Kenwood TS-830 User manual

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Kenwood TS-830
Survival Guide
PART I
edited by
Olaf Rettkowski DL9AI

2
VERSION
Kenwood TS-830 Survival Guide, ed. Olaf Rettkowski, DL9AI, ver.1.2, 03 Dec 2002
REFERENCE
This is a collection of material found on the net. For reference and further information visit
the following sites and/or see the following papers:
http://myweb.tiscali.co.uk/martin.atwsm/TS830S.html , Martin, G1XGX
http://www.vcnet.com/measures/830.html , Richard L. Measures, AG6K
http://www.eham.net
http://www.mods.dk
http://groups.yahoo.com/group/Amateur-repairs
http://www.kenwood.net
Kenwood TS-830S Operating Manual
Kenwood TS-830S Service Manual

3
1Preface .........................................................................................................................6
2Read first ! ...................................................................................................................6
3History of this document ............................................................................................7
4To-Do list .....................................................................................................................7
5General Description....................................................................................................7
6Problems and known Fixes ........................................................................................8
6.1 Excessive delay in relay control signal to external amplifier--which causes hot
switching in the amplifier's RF relays ..........................................................................8
6.2 Frequency drift..............................................................................................................8
6.3 Frequency drift during warm-up...................................................................................9
6.4 TS-830S Frequency Drift - "FIX" switch.....................................................................9
6.5 Frequency jumping .......................................................................................................9
6.6 Intermittent shift in display and operating frequency.................................................10
6.7 Intermittent ALC on transmit .....................................................................................11
6.7.1 Problem 1: Intermittent ALC indication [TX] on only one band ...............................11
6.7.2 Problem 2: Intermittent ALC on transmit...................................................................11
6.8 Lack of crispness in receive audio..............................................................................11
6.9 Lack of crispness in transmit audio ............................................................................12
6.10 No power output on most bands .................................................................................12
6.11 Noisy or intermittent front panel control potentiometers [pots].................................12
6.12 On the AF-AVR Unit, the 4-pole relay contacts which switch the bias to the finals
may fail after extensive use. .......................................................................................12
6.13 Peak-distortion in the RX audio .................................................................................13
6.14 Poor, transmit, SSB carrier-suppression after alignment............................................13
6.15 Power-output falls off when the key is held down .....................................................13
6.16 Premature 12V pilot lamp burnout .............................................................................13
6.17 Rapid jumps in VFO frequency..................................................................................14
6.18 Receive [RX] signals intermittently drop roughly 40 db............................................14
6.19 Receiver AGC-overshoot, causing receive audio-distortion on voice-peaks and
concurrent S-meter overshoot.....................................................................................14
6.20 Television interference with the radio transmitting into a 50 Ohm, shielded
termination..................................................................................................................14
6.21 Receive suffers or goes out after QRO modification..................................................15
6.22 Transmitter "talkback"................................................................................................15
7Problems and Hints from Newsgroups ...................................................................16
7.1 Beware of high voltage!!!...........................................................................................16
7.2 No sidetone when keying CW, VOX doesn't work on CW........................................16
7.3 Resistor replacement after grid-to-cathode short of the 6146 tubes ...........................16
7.4 Difference between 6146B und 6146W tubes ............................................................16
7.5 Slow power drop-off...................................................................................................17
7.5.1 Slow power drop-off: Answer 1 .................................................................................17

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7.5.2 Slow power drop-off: Answer 2 .................................................................................17
7.5.3 Slow power drop-off: Answer 3 .................................................................................17
7.5.4 Slow power drop-off: Answer 4 .................................................................................18
7.6 Low power output.......................................................................................................18
7.6.1 Low power output: Answer 1 .....................................................................................18
7.6.2 Low power output: Answer 2 .....................................................................................18
7.6.3 Low power output: Answer 3 .....................................................................................18
7.7 Intermittend drop of power output .............................................................................19
7.8 Problem peaking Drive control ..................................................................................19
7.9 Intermittent loss of drive to final ................................................................................19
7.10 No dip on the plate current and no or small output ....................................................20
7.11 Reducing power output to QRP-like levels, No.1 ......................................................20
7.12 Reducing power output to QRP-like levels, No.2 ......................................................20
7.13 Increasing power output / QRO-modification, No.1 ..................................................21
7.14 Increasing power output / QRO-modification, No.2 ..................................................21
7.15 Intermittent loss of audio............................................................................................22
7.16 Final tubes replacement and neutralization ................................................................22
7.17 Low power output on 160 m only ..............................................................................22
7.18 Crystals for FIX band selection..................................................................................23
7.19 Changed DRIVE setting after final tubes replacement is normal ..............................23
7.20 Difference between TS-830 and TS-830 "gold label"................................................23
7.21 Microphone impedance matching ..............................................................................23
7.22 Problem with TS-830 TX relay ..................................................................................24
7.23 No operation on WARC bands...................................................................................24
7.24 Receiver signal attenuation when keying the microphone or rocking the bandswitch
....................................................................................................................................25
7.25 VOX trip problem.......................................................................................................25
8Maintenance Procedures..........................................................................................25
8.1 VFO Lubrication ........................................................................................................25
8.2 Fan Lubrication ..........................................................................................................26
8.3 VBT [Variable {selectivity} Bandwidth Tuning] Oscillator Alignment [approx.
8375 KHz] ..................................................................................................................26
8.4 USB/LSB Carrier Oscillator Alignment.....................................................................27
9Modifications.............................................................................................................27
9.1 AMTOR modification ................................................................................................27
9.2 WARC modification...................................................................................................28
9.3 RIT / XIT modifications.............................................................................................28
9.4 VFO-230 fine tune mod..............................................................................................28
9.5 TS-830S Low Voltage Supply Optional Improvements ............................................28
9.6 Kenwood TS-830 filter modification .........................................................................29
9.7 TS-830S Operation on 240 V AC ..............................................................................30
9.8 TS-830S Noise Blanker Optional Improvements.......................................................30
10 Product Reviews .......................................................................................................31

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10.1 Opinions and Ratings of TS-830 owners....................................................................31
10.1.1 Great Radio, Rating: 5 of 5.........................................................................................31
10.1.2 I miss mine, Rating: 5 of 5..........................................................................................32
10.1.3 Good but aging, Rating: 5 of 5 ...................................................................................32
10.1.4 TS-830 The Best of the Best, Rating: 5 of 5...............................................................32
10.1.5 Brilliant audio from 830, Rating: 5 of 5 .....................................................................32
10.1.6 Excellent Radio on the used Market, Rating: 5 of 5...................................................32
10.1.7 Excellent Radio, Rating: 5 of 5...................................................................................32
10.1.8 A quality classic, Rating: 5 of 5..................................................................................33
10.1.9 Still Impressive after all these years, Rating: 5 of 5 ...................................................33
10.1.10 One of the very best, Rating: 5 of 5............................................................................33
10.1.11 Will never say 'goodbye', Rating: 5 of 5.....................................................................33
10.1.12 Nice, Rating: 4 of 5.....................................................................................................33
10.1.13 Nice transceiver, Rating: 5 of 5 ..................................................................................34
10.1.14 Great Rig. Rating: 5 of 5.............................................................................................34
10.1.15 Like putting down a friend; rating. 5 of 5...................................................................34
10.1.16 Going strong after 18 years, Rating: 5 of 5 ................................................................34
10.1.17 TS-830S Finals last forever, Rating: 5 of 5 ................................................................34
10.1.18 Good radio...with a question to other TS-830S owners, Rating: 4 of 5......................35
11 Connectors and Plugs ...............................................................................................36
12 Index...........................................................................................................................37

6
1 Preface
I purchased a Kenwood TS-830S on the used market after passing the ham exam in 2001.
Months before I was searching the internet extensively to get an idea of how an newcomers
shortwave transceiver must look like, especially what features it must have and which of them
are not essentially. The costs did play an important role: my personal limit was 500$ for the
transceiver (a few weeks later the MFJ-949 manual antenna tuner took me again 200$… and an
MC-50 mike from Kenwood again 70$). Regardless of the many (mostly technical) comments
about this decision, which are to be found on the net, my personal opinion is that a transceiver
must look like a transceiver – that means, there must be a minimum amount of metallic shining
knobs and switches and in generally a solid design.
First time using it I didn't really know what I was doing, but the TS-830 knew…and did what it
was expected to do… It didn't take a long time until I encountered the first problems: there was
no output in SSB-mode and I realized the low power output on the upper bands. And here the
story begins. I searched for technical descriptions and procedures to do these repairs and found
them wide dispersed on the Web. And so I started collecting them, in the beginning for personal
use only.
The problem of no SSB TX operation was quite easy to fix: a broken copper ground connection
on the back of the IF board caused the mike amplifier to fail. Soldering a simple insulated wire
to another ground point on this board and I was in business on SSB. Changing the tubes and
re-neutralizing in generally is a simple procedure, but if one had never done this before, even
simple things can be difficult or at least take a long time. This may be a waste of time – on the
other hand its is only the intensive dealing with a problem that makes us learn and achieve
experience and skill.
Many hams do know how to handle and repair older equipment, but a growing number doesn't
anymore since they grew up with solid state technology only or are not interested in the older
rigs. Many newbees are taught to avoid boatanchors, they hear that dipping the plate and
peaking the load of a tube final is much too tricky and time wasting (takes 5 seconds or less…)
to make dealing with these rigs worthwhile.
If You are the proud owner of one of these 20-year old TS-830's made by Trio-Kenwood You
are probably interested in old equipment – if not for liking so for necessity. This collection of
articles and information about the TS-830 should serve as a reference for those who need it. If
You find this file useful, You are invited to propagate it over the net. If You add Your
experience or improve it's content, please email a copy to me. Feel free to remove my name
from the cover page if You want – I'm not the author but only the collector of this stuff. Please
excuse my poor English…
Halle, Germany, June 25th 2002
VY 73's
Olaf Rettkowski DL9AI
Email: [email protected]
2 Read first !
All information provided here is not verified. Use the modifications and procedures at Your own
risk. Please keep in mind, that malfunction or damage of Your equipment may occur, even if
You follow the instructions of these document carefully.

7
Please make sure You have the latest version of this document. Check
http://www.geocities.com/om6523.
3 History of this document
• First version (1.0) 25th June 2002 by Olaf Rettkowski DL9AI
• Latest revised version: (1.1) 13th Nov 2002
4 To-Do list
• For part II "Manuals": Rescanning of the layout and the board schemes to make them
READABLE; the additional red lines indicating power supply lines are to be regarded.
• Adding of general information how to repair a rig: measurement equipment, procedure;
where to start for locating errors – the information provided with the service manual
seems to be not sufficient, especially for those of us not so familiar with sophisticated
electronic repairs.
• Adding of personal experience in using a TS-830: maybe someone has developed new
procedures or can give hints helpful in operation.
• Adding of detailed descriptions of the function of certain parts – which resistor or
transistor has what function. This will help not only in fixing problems of this rig but
provide some kind of teaching material to learn electronics…
• Adding of test reports of older ham radio magazines, (if allowed to publish…)
5 General Description
(Author: Richard L. Measures, AG6K)
The ancient TS830S is a still a remarkable radio.
Processing: The processor is clean and effective. When an 830 processor is turned on, the S-
meter at the receiving end noticeably increases and the perceived volume increases - yet the
audio is clean and understandable. I have never observed a modern transistor-output radio that
could perform this feat. There are several factors at work here. First-off, RF, instead of AF,
clipping was used to maximize the effectiveness of the processor. Naturally, RF clipping
generates IMD products. Trio-Kenwood engineers minimized this problem by utilizing a post-
RF clipping 455 kHz IF ceramic filter to clean up the IMD products. After the processed
transmit IF signal is filtered and converted to the operating frequency, it is amplified by an
extremely low-distortion tube-type RF amplifier that utilizes [Collins Radio, Co.] RF-negative-
feedback. The net result is a clean, effective RF processor that is not objectionable to listen to -
provided the indicated processing level is kept under roughly 8db.
Strong signal overload: The 830 has extremely low VFO phase noise. When listening to a weak
signal that is 5 kHz away from a strong local signal, the 830 outperforms many modern radios.
However, at signal spacings of 50–100 kHz, modern radios are better at tolerating strong local
signals. On transmit, the 830 generates a remarkably clean transmit signal with a minimum of
adjacent-frequency phase noise.
S-meter accuracy: The 830's S-meter is fairly accurate. Above approximately S-5, one S-unit
equals pretty close to the required 6 db. Above S-9, the db scale is reasonably accurate.
Naturally, calibrating the S-meter helps. Some modern radios indicate 3 db per S-unit--a 50 %
error, and 20 microvolts = S-9. Whatever happened to the Collins standard of 100 microvolts =

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S9?
Drawbacks:
Slight frequency drift during warmup. This problem can be ameliorated by one of the fixes
described below.
2. Inability to work split frequency at typical frequency differentials.
3. As with any ancient machine, maintenance requires an extra effort. However, newer radios
appear to be far from trouble free. I have spoken with owners who had to return their highly-
complex new radios to factory service five times during the first year.
6 Problems and known Fixes
6.1 Excessive delay in relay control signal to external amplifier--which
causes hot switching in the amplifier's RF relays
Cause:The RF relay in the TS-830S also switches the external amplifier relay control line.
Thus, the amplifier relays can not begin to close until the RF-relay in the TS-830S has closed.
Fix: Install a NPN >200V switch transistor [MPS-A42 or=] in the TS-830S to take over the job
of relay control line switching. The input [base] of the switch transistor is driven by the +12V on
transmit signal ["RL"] that drives the coil of the TS-830S' RF-relay, RL1. The base-current is
limited to approx. 11 mA with a 1 KOhm series resistor. Connect another 1 KOhm resistor
between the emitter and the base to drain off the stored charge in the base. The emitter connects
to chassis-ground. The collector connects to the wire from pin 4 on the Remote socket. Pin 2 of
the remote socket should be connected to chassis-ground or to the emitter of the transistor. The
NPN transistor can only switch a positive relay-control line voltage, so this circuit will not work
on negative relay-control voltage amplifiers like the SB-200 and the 30L-1. The fix is to convert
these amplifiers to [standard] positive V relay control line polarity. A solid-state electronic
cathode bias switch [ECBS] is useful in this application. Such a circuit is shown in QST
magazine, January 1994, "The Nearly Perfect Amplifier."
6.2 Frequency drift
(Author: Tommy Hayes)
Before making any internal modifications for the frequency drift please try this:
Take both the top and bottom covers of the rig off the transceiver. Find each and every philips
screw that you can get to with a philips screw driver and loosen it about 1/4 of the way. After
doing that, retighten the screws.

9
This includes but is not limited to each and every PC board that you can get to. Done this with
my 830 that had severe drifting problems and so far (4 months) have not had a problem with the
drift yet on any band.
6.3 Frequency drift during warm-up
Cause: Change in humidity and temperature inside the VFO Unit.
Semi-Fix: The amount of frequency-drift during warm-up can be reduced if the radio is
equipped with a "damp-chaser" resistor that will keep the VFO slightly warm when the radio is
switched off. This is accomplished by placing a 7.5 KOhm nominal, 2 W metal-oxide-film
[MOF] resistor in parallel with the contacts of the power-switch, S9. When the radio is off,
roughly 115 VAC appears across the switch contacts, which causes the resistor to dissipate heat
underneath the VFO. The full lead-length resistor is mounted on two, standoff insulators which
are fastened to the shield partition that is between the VFO and the PLL Unit. The resistor is
positioned under the VFO shield-can. A strip of insulating tape is placed on the bottom of the
VFO shield-can and on the inside of the bottom of the 830 cabinet to provide extra electrical
insulation in the event that the insulating coating on the MOF resistor fails. Each resistor lead
should be placed inside approx. 28 mm of heat-resistant insulating-tubing, such as Teflon, so
that the wires can not touch chassis ground.
6.4 TS-830S Frequency Drift - "FIX" switch
(Author: Alan N5LF)
If your TS-830S drifts or jumps frequency up & down 100 to 200 Hz, the problem may be a
dirty FIX switch. The FIX switch disables the VFO and is used for crystal control. The switch
conducts voltage in both the on (crystal) and off (VFO) positions. Dirt, corrosion, or wear makes
the switch provide uneven voltage to the VFO and therefore causes the drift/jumping.
To test for this problem, wiggle the FIX switch or press it in & out a few times and see if the
drift/jumping stops for a few minutes.
Temporary cure: Spray the switch with contact cleaner. This works for me for 1 to 3 months,
then it starts acting up again.
Permanent cure: Use a jumper to bypass the switch, so it is permanently in VFO position.
If someone knows a solution that doesn't disable the FIX switch's function, please let us all
know.
(These and other hints mentioned also in section 6.5, page 6)
6.5 Frequency jumping
Alan Wormser had the problem caused by the FIX switch (see section 6.4, page 9) and also
supplied some other answers to his question:
1. Grounding the AF/AVR board: Connecting a wire from TPG post to ground screw, and
inserting star washers between board and heat sink, in accordance with Kenwood bulletin -
appeared in QST Hints & Kinks in the mid-1980s. (Ian G3SEK, Art N2AH, Paul K0PW, Frank
Kb0ZFN, and many others)
2. The grounding screws on the PC boards may not make good contact. (Bill W7US)
3. Although I have not seen this problem in a Kenwood, I have seen it in Icom and Yaesu- both
with the same cause- small single turn variable caps. In case of the Yaesu it was a frequency
netting cap on a heterodyne oscillator- drove me nuts. It occurred randomly and never when I

10
had the rig open. A hint from another ham sent me looking in that direction. Replaced 2 or 3 and
that was the end of it. (Dale W4OP)
4. Check the external VFO DIN jack in the rear. Actually you will need to check it from the
inside. If you have one, put the matching DIN plug into the jack and pull it in and out several
times. This is a common problem with the 830. This jack has a contact which is shorted
WITHOUT an external VFO. If the contacts get dirty, it will do exactly as you described. You
might also want to spray a small amount of contact/electronic solvent on the jack and do the
plug in and out. (Brian KJ5AG)
5. I had what sounds like the same problem with a TS-830S. Turned out the FIX switch labeled
was intermittent. It is in the path of the voltage to the VFO and if it has some extra resistance,
the frequency would change. I tried "Deoxit" and that worked for a while but finally I jumpered
around the switch contact since I never used crystals for operating. Try operating the switch
many times and see if goes away for a while. (Dennis NT0V)
6. Maybe one of the xtal trimmer caps is going bad. The center pivot point is getting rusty.
Contact cleaner will fix this for a month or so but you need a new one.
6.6 Intermittent shift in display and operating frequency
(Author: Trio-Kenwood Communication, Inc.: “TS-830 frequency shift”)
Some users may report an intermittent shift in the display and operating frequency. This may
typically be a 1 to 4 KHz random shift. Cause will be a loose grounding screw on the AF/AVR
unit heat sink.
On the AF/AVR unit X49-1140-00, there are three self-tapping screws holding the aluminum
heat sink to the PCB. These also supply the ground connection to that section of the board.
Between the heat sink and PCB foil, add a tooth-lock washer N17-1030-41 at the two self-
tapping screws on the side of the heatsink that has the two transistors attached. (The remaining
screw already has a lock washer.)
When replacing the board to the chassis, add a solder lug E23-0420-05 to the heat sink
mounting screw as shown, and tighten all screws for this board. Solder an insulated lead
between the TPG (Test Point Ground) wrap post adjacent to C81, and the added solder lug.
Procedure:
1. Remove the top cover (8 screws) and unplug the speaker.
2. Remove the bottom cover (8 screws).
3. Remove 5 screws holding the AF/AVR unit and swing the board over. Leads do not have to
be unplugged.
4. Add two tooth-lock washer as shown.
5. Replace the circuit board and heat sink to the chassis, adding the solder lug as shown.
6. Solder a jumper between the TPG wrap post and the added solder lug.
7. Replace the top and bottom covers.

11
Installation time for this procedure is 1/2 hour or less.
6.7 Intermittent ALC on transmit
6.7.1 Problem 1: Intermittent ALC indication [TX] on only one band
This indicates that the trouble is different than was the case in Problem 2 {which would be the
same on all bands}. The bandswitch is usually the culprit. This occurs most often on the 7 MHz
band-switch position, on the two, rear-most bandswitch sections in the RF Unit.
Cause: The bandswitch (also) has dissimilar-metal crimp-connections that turn into semi-
insulators due to electrolysis. This takes place between the bandswitch's riveted-on,, tin-plated,
stationary contacts and the copper-foil on the printed circuit board [PCB]. Fix: Apply a small
amount of conductive-paint where the stationary switch contact touches the copper-foil on the
PCB. The conductive-paint will be drawn, by capillary-action, into the problem area where the
two, dissimilar-metals touch each other.
6.7.2 Problem 2: Intermittent ALC on transmit
Cause: As in problem 1, this problem is usually caused by an intermittent crimp-connection on
the pins at the ends of the coax cable that brings the transmitter intermediate-frequency ["TIF"]
signal from the IF Unit to the RF Unit. The ends of the TIF coax cable can be found in the same
connectors that were discussed above, in Problem 1.
The fix is the same: Make good electrical connections at the crimps on the connectors' pins.
6.8 Lack of crispness in receive audio
Cause: The intermediate-frequency bypass capacitors, C62/C63, at the audio output of the
product-detector, are so large that they noticeably attenuate the treble audio frequencies.
Fix: Reduce the value of these capacitors and reduce the terminating resistance, R78, across the
output capacitor, C63, to reduce the treble attenuation. R78 is changed from 47 KOhm to
approx. 3.3 KOhm - 4.7 KOhm. C62 and C63 are changed from 0.022 µF to 0.0075 µF -
0.01 µF. {the factory value varies depends on the radio's S/N} These components are on the IF
Unit, about 4cm in front of the left-rear corner. Note: After this change is made, the full range of
audio frequencies will be present in the background/"sky" noise. It is beneficial to compensate
for this by turning down the RF Gain control until the sky noise decreases to a comfortable
level. [This is the main reason to have an RF gain control.]

12
6.9 Lack of crispness in transmit audio
Cause: The RF-bypass capacitor, at the collector of the 1st audio amplifier, is so large that it
bypasses the higher audio frequencies along with the RF. {The amount of treble-rolloff in a
stock radio is about 4.5db at 2800Hz.}
Fix: On the IF Unit, at Q19, change C106 from .015µF to approx. 0.001µF. Q19 can be found
directly behind the filter space for the larger of the two, optional CW-filters.
6.10 No power output on most bands
Cause: This is usually due to the final unit bandswitch being out-of-sync with the bandswitch
shaft. This problem is caused by a cracked, plastic shaft-coupling between the RF unit and the
final unit. Trio-Kenwood did not use Locktite, or a similar thread-locking compound, so the
setscrews in the coupling had to be over-tightened, by the assembler, to prevent the setscrews
from loosening during operation. The constant stress on the plastic, caused by the combination
of ordinary use and the over-tightened the setscrews, eventually causes the plastic couplings to
crack.
Fix: Remove the cracked plastic coupling and either epoxy it together, buy a replacement
coupling from Trio-Kenwood, or find a replacement shaft coupling made from metal. Use
Locktite in the setscrew threads during re-assembly so that the set-screws will not need to be
overtightened. Plastic shaft couplings can be cracked by overtightening the setscrews. Allow the
Locktite to set 2 minutes before operating the switch.
6.11 Noisy or intermittent front panel control potentiometers [pots]
Cause: The grease, that is used to lubricate these pots, oxidizes and becomes gummy with age,
causes an intermittent connection between the rotating wiper-arm and the resistance-film in the
pot.
Fix: Stand the radio up on its back, on the original rear packing cushion. Pull-off the knobs of
the offending pots. Using a syringe and small-gauge needle, inject TCE degreaser down into the
clearance spaces next to the concentric shafts of these pots, rotating the shafts back and forth to
loosen the gummy grease. When the pot is no longer intermittent, inject GC Electronics Co.
"De-Ox-Id" . This material should be thinned with about 50% TCE to help fluid penetrate down
into the pot.
Note: TCE is carcinogenic and should be used with good ventilation.
6.12 On the AF-AVR Unit, the 4-pole relay contacts which switch the bias
to the finals may fail after extensive use.
This relay is neither cheap nor easy to replace. The failure is caused by th.00000 repeated
shorting to ground of a charged capacitor in the bias circuit by one set of the relay contacts
during T/R transition.
Fix: On the circuit diagram, find the leftmost set of contacts. The arm [movable contact] of this
set of contacts is grounded.
Fix: cut the trace from the arm to ground in 2 places about 5mm apart. Remove the foil between
the cuts. Solder a approx.100 Ohm, 0.25 W resistor across the gap. The resistor will limit the
peak discharge current during T/R-R/T switching to a value that will not burn the relay contacts.

13
6.13 Peak-distortion in the RX audio
Cause: This is usually caused by one or more problems in the product-detector [PD] on the IF
Unit. These problems are: 1. Unmatched PD mixer-diodes, and/or 2. Too-much 455 KHz
injection-voltage at the local-oscillator {LO} port of the PD. 3. No terminating-resistor is used
at the LO-port of the PD. This allow the IF-signal to modulate the LO, which adds distortion.
Fixes: Replace the PD diodes, D20, 21, 22, and 23, with 1N6263, Hewlett-Packard HSCH-
1001, or similar Schottky-diodes. {D20-24 are on the IF Unit, about 4 cm in front of the left-rear
corner}. Add a approx. 100 Ohm, approx. ¼ W resistor from the junction of R75 and R76 (470
Ohms each) to circuit common. If you have an oscilloscope or an RF-voltmeter, the correct LO-
voltage, measured across the added 100 Ohm terminating-resistor, should be approx. 600 mV
peak to peak on both USB and LSB. This voltage can be set by alternately adjusting L19 and
L20, which are about 3 cm northeast of connector-11.
Note: This test point is also available, from the component side of the board, on pin 4 of
connector-11, to circuit common.
6.14 Poor, transmit, SSB carrier-suppression after alignment
Cause: Unmatched balanced-modulator diodes.
Fix: Replace the original, Germanium diodes, D29 thru D32 with 1N6263, Hewlett-Packard
HSCH-1001, or similar Schottky diodes and re-null the carrier with TC3 and VR4 on the IF
Unit.
Note: HSCH-1001 diodes are hybrid-type Schottky diodes, which have a lower noise-figure at
audio frequencies than ordinary Schottky diodes. Ordinary Schottky diodes will also do the job.
6.15 Power-output falls off when the key is held down
Cause: This is usually the result of electron emission from the screen-grids in the 6146Bs.
Screen-emission is caused by operating the filaments of the tubes with excessive filament-
voltage for many hours. The excessive filament-voltage overheats the cathode, which causes the
cathode's electron-emitting barium coating to slowly evaporate and stick to the screen-grid.
When the contaminated screen gets hot during key-down operation, the barium particles on the
screen emit electrons in the wrong direction, toward the cathode, which causes the anode
[plate]-current, and power-output, to fall-off.
Fix: Replace the 6146B’s with new tubes and insert, for 120 VAC or 240 VAC operation, a
0.51 Ohm nominal, 2 W, Metalfilm [MF] resistor in series with the Final Unit PCB-end of the
violet-colored wire, that connects the heater switch to the PCB {that the 6146B sockets are
mounted on}. The added voltage-drop in this resistor will decrease the filament-voltage, at the
tube-sockets, to approx. 6.1V and will greatly prolong the life of healthy tubes without altering
their power-output or IMD.
6.16 Premature 12V pilot lamp burnout
Fix: Reduce the pilot lamp operating voltage. Put a suitable resistor in series with the wire that
supplies power to the pilot lamp terminal strip on the bottom of the radio, near the VFO. Start
with approx. 20 Ohms, 0.5W. For optimum life, the pilot lamps should be operated at roughly
8-9 V. Reducing the voltage to the meter pilot lamp requires a separate resistor of roughly
68 Ohms.
Note: inexpensive replacement lamps are available at hobby shops that sell miniature trains.

14
6.17 Rapid jumps in VFO frequency
Cause(s): [1] This can be caused by fluctuation in the 9V regulated power-supply voltage,
which is the result of an intermittent connection between the AF-AVR [automatic voltage-
regulator] Unit's circuit-common and chassis ground. [2] The problem can also be caused by a
dirty ground-connection wiper on the rotor of the VFO tuning-capacitor.
Fix(s): [1] Solder a wire to the "TPG" terminal, next to C81, on the AF-AVR Unit. On the other
end of this wire, solder a #6 ground-lug with locking teeth. The ground-lug is placed under one
of the nearby sheet-metal-screws that fastens the AF-AVR Unit to the chassis. [2] Remove the
VFO from the radio using a 3 mm Allen-wrench. Pull the pilot-lamps from their grommets and
pull the electrical plug from the rear of the VFO assembly. Remove the VFO shield-can {5,
Phillips-head screws} and clean the gummy grease from the wiper on the tuning-capacitor's
rotor shaft with solvent. Lubricate the wiper with contact cleaner.
6.18 Receive [RX] signals intermittently drop roughly 40 db
Cause: This is usually due to a poor electrical connection at the crimps on the contact-pins at
the ends of the "RIF" [receiver intermediate-frequency] coax cable, which is above the chassis.
This cable carries the 8830 KHz RX signal between the RF Unit, Connector-5, pin 2, {to right
of VFO} and the IF Unit, Connector-6, pin 6, {to left of VFO}. The crimped-on pins in these
connectors have a tin-plating. The coax has copper conductors which, along with moisture from
the air, creates a dissimilar-metal electrolytic action that eventually turns the crimp-connection
into a semi-insulator.
Fix: Make a good electrical connection between the copper and the tin-plating, where the
center-conductor wire protrudes beyond the crimp, by applying solder or a conductive-paint
{neater than soldering and easier to use} such as GC Electronics Co. Silver-Print. This paint can
be applied to the target area with the end of a partially straightened paper-clip. To remove the
female pins from the connectors, using a jeweler's screwdriver, depress the pin's ratchet-tab,
which is accessible through the slot in the side of the connector and simultaneously pull the
contact and wire out through the back of the connector. To avoid mixups, remove one pin, repair
and replace it before removing the next pin.
Note: It is easier to gain access to Connector-5, on the RF Unit, if the Counter Unit is moved
slightly {4, Phillips-head screws}.
6.19 Receiver AGC-overshoot, causing receive audio-distortion on voice-
peaks and concurrent S-meter overshoot
Cause: Too-much R/C delay in the AGC-bus at the second-gate of Q1 on the RF Unit.
Fix: Replace R12 [1M Ohm] with a 10k Ohm to 51k Ohm unit. Q1 and R12 are located at the
front, left of the RF Unit. It is possible to clip the leads of R12 from the top of the circuit board
and install the lower-R unit without removing the RF Unit from the radio. An alternate method
is to remove the AF-AVR-Unit and remove the cover plate that is underneath it. This allows
easier access to the trace side of the RF-Unit circuit board.
6.20 Television interference with the radio transmitting into a 50 Ohm,
shielded termination
Cause: This is usually caused by VHF harmonic energy leaking out through the line-cord.
Fix: Add one or two, µ=850, VHF-attenuator ferrite beads in series with each of the two wires
in the line-cord. It is also helpful to add a approx. 470 pF, 1 KV, disc-ceramic, bypass-to-ground

15
capacitor, on each wire, on the line-cord side of the ferrite beads. If the bypass capacitors are
added, it is advisable to replace the 2-wire line-cord with a 3-wire, grounding line-cord and
plug. The green ground-wire should be connected to the chassis of the radio. This provides a
ground-return for the small 60 Hz AC-current that flows through the bypass-capacitors.
6.21 Receive suffers or goes out after QRO modification
(Author: Frank J. Lukas, Jr., North Ridgeville, OH)
I would like to pass on the problem I had encountered in connection with the QRO modification
to the Kenwood radios TS830S, TS-530S and the TS-530SP. The problem occurs after many
hours of long winded QSO's. It seems that with the increase in the screen voltage from 210 to
300 volts, R37 on the RF unit (#X44-1360-00) heats up tremendously and will change it's value
so greatly that even the receive either suffers or goes out totally. R37 originally is Metalfilm
resistor at 3.3 KOhm and is 1/2 watt. I have changed mine to a Metalfilm as original same value
but have used a one watt resistor. The brand I was able to get was RCA and I suppose there are
better on the market. This is a 2 % tolerance. Three units that I know of have had this problem
that I took care of in this area alone. Two units were TS-830S and one a TS-530SP. Just thought
I would pass that information along for what it is worth.
6.22 Transmitter "talkback"
(Author: Trio-Kenwood Communication, Inc.)
Transmitter "talkback", either with or without a linear amplifier, may be eliminated by adding a
filter at the receiver audio power amplifier.
On the AF unit X49-1140-00 at Q4, cut the 12 V DC B+ line between R47 and C28, and add a
1 µH choke (L40-1092-02) in-line. Add a 0.01 µF cap (C52-1710-36) from the IC pin 1 to
ground, as shown using a 3 mm lug (E23-0015-04) under the IC mounting screw on the heat
Sink.
Installation time for this procedure is ½ hour or less.

16
7 Problems and Hints from Newsgroups
7.1 Beware of high voltage!!!
Speaking of smoke…
Years ago I laid my forearm across the plate connectors of a TS-830 that was in transmit mode
(don't ask why...), 800 V DC plus RF, about 30 watts worth.
Next thing I knew I was sitting on the floor, looking at my arm... the flesh was crawling around
on it's own, quivering. My wife came running down and said "What's wrong, I heard you yell!".
I told her I didn't yell. She said I did!
Assessing the damage, I felt thankful that it was just the right arm, and that it apparently didn't
go through my heart...much. Then I spotted 'em... two little white burn marks on my left index
finger.
73, and be careful, especially around 120/240 V AC, and tube rigs. And, it's antenna season, that
means take special care to know where your power lines are. The typical high-line behind our
homes (4-8 KV) can jump to metal on a dry day so watch it when putting up antennas. Plasma
burns hurt.
7.2 No sidetone when keying CW, VOX doesn't work on CW
(The VOX works on SSB, so the VOX GAIN control is not left in the 'Off' position…)
The sidetone generator is used to key the VOX in CW. On the audio unit board, there is a Q1
that is the sidetone oscillator. Look at TP1 on that board when keying the key, you should see an
audio waveform of several hundred millivolt peak-to-peak there. Or us a digital voltmeter on
AC volts, should see a low-level AC voltage that corresponds to the CW key action. If it's not
there, you either have bad Q1 (2SC945, which every ham should have a couple of at all times!)
or some other component bad. Q1 is a run of the mill audio oscillator.
According to a Transistor data book, the 2SC945 is equivalent to either the BC548, or 2N3094.
Both being NPN capable of handling 100 mA at up to 50 V.
(ATTENTION: success of the procedure is not reported)
7.3 Resistor replacement after grid-to-cathode short of the 6146 tubes
(For TS-520,TS-820,TS-530,TS-830)
On these rigs, if the 6146 tube(s) develop a grid-to-cathode short (the usual mode of failure), the
1 W 10 Ohm cathode resistor will blow, makes noise and smoke. The line fuse resistor may or
may not blow. This resistor acts as a fuse; DON'T oversize it when replacing. Replace both
tubes, and replace the resistor with same size, such as Radio Shack 271-0080.
Hint: Metal film resistors "blow" more cleanly than carbon comp, and break the circuit more
quickly.
7.4 Difference between 6146B und 6146W tubes
The highly touted and easily available so-called "heavy" 6146W actually has less plate
dissipation than the 6146B (25 W for the W-type versus 35 W for B-type). That is why the B
version is so much more expensive. It's not really necessary unless you have done the high-
power screen voltage mod on these rigs, but that's another story...

17
7.5 Slow power drop-off
Question: I've been tuning my 830S through a good 50 Ohm dummy in the tune mode and pre-
tuning the antenna tuner in this mode also so I would not damage the finals. The last two days I
have noticed that after warmup, tune and pre-tune of the tuner the power will slowly drop of
from 110 W to nearly 50 W. Another interesting thing, during the tune-up stage, as I max the
drive I noted it would max.. then slowly increase at about 1/4 more than the max. I would then
continue with dipping the plate etc. with 100 to 110 W out. If I held the key on tune or CW I
would peak at 100 then the power would slowly drop to 50 W over 10 seconds. I have not held
the key longer than that… (Glen KD5NVC)
7.5.1 Slow power drop-off: Answer 1
The 830S is now officially an "old" rig, since it was on the market in 1980, some 21 years ago.
If it has the original tubes, it's very likely they're very worn out! Even if it's on its second or
third set of tubes, this is quite likely, especially if the tuning process is ever prolonged.
There's no reason to spend a lot of time tuning up a TS830S. Adjust the external antenna tuner,
if you must use one, with the 830S running very low power in the CW or RTTY mode, where
the power can be turned down to almost nothing. Once the tuner is all adjusted for the best
possible match, run the drive back up and spend the next five seconds optimizing the PA tuning.
If it takes longer than that, you're really doing something wrong. There's no reason to dip the
plate current, etc, that's a guideline.
I used to tune my 830S "on the fly," by simply dialing up a frequency where I wanted to make a
call, pressing the mike button and making the call while quickly adjusting the TUNE and LOAD
controls for maximum output on either the 830's relative output meter or an external wattmeter,
using my voice as the signal. That gets it tuned fine in just a few seconds.
The leading cause of 6146 and 12BY7 failure in the Kenwoods has always been "tuning up."
Keep it brief, and do your adjustments at low power, then a very short touch-up of only the PA
TUNE and LOAD controls (no reason to go back and re-peak the driver stage, it won't change),
and you're done. I'd surely change the 12BY7 and the 6146's, follow the neutralization
instructions in the manual for re-neutralizing the 6146's, put it back together and keep tune-ups
short! They'll all last about ten years if you follow that rule. (Steve WB2WIK/6)
7.5.2 Slow power drop-off: Answer 2
Hi Glenn: If the plate voltage on the finals is not dropping, I would definitely suspect the finals.
Most power tubes begin dying the same way - by losing emission after they have been working
a few minutes. I suspect I have changed a thousand or more of various types from 45's and
6K6's up with that same problem. (Pete AC5E)
7.5.3 Slow power drop-off: Answer 3
My TS830 is in its 20th year with me.... a year and a half ago, I replaced the 12BY7 after
experiencing the same symptom. Touch wood, I'm still on the original finals. Having used tube
finals in my HF rigs since I got licensed 36 years ago (yikes!), I have found the power drop-off
symptom to have always been a dying tube.
By the way, I don't think you have to be overly careful about tune-up - just don't keep the key
down too long, and it can be done fairly quickly. I adjust the load for maximum output, dip the
plate current, then go again with the load for maximum output in my outboard power/swr meter,
and back again to dip the plate current. Each time the dip is less deep, and output power
increases. Hey -- after all these years I still love this rig, which is as comfortable as an old

18
shoe - great audio, a good receiver, and very reliable and rugged. This radio has given me its
money's worth and more so - it's been a worthwhile investment, and I still don't see retiring it --
I'm still enjoying it too much!!! (4X1MK)
7.5.4 Slow power drop-off: Answer 4
If I remember correctly, you aren't risking anything by installing your new 12BY7. The last time
a 12BY7 went bad while I was using it, in a Tempo ONE, the current increased (while output
went down?). I didn't live near any place I could get a driver tube, so I tried short transmissions
-- blew the fuse (the fuse protected my rig from ME!) (AE7G)
7.6 Low power output
Question: I recently purchased a TS-830S used, the unit is clean with no evidence of abuse.
After proper tune-up using a Heathkit dummy-load and a good swr/watt meter for HF can get
80 W PEP max. on CW. Specs show that I should get 100 to 180 max on CW. Can this be the
6146B or the driver tube? bias is 60 to 65 mV, I have double checked ALL tuning as per
Kenwood instructions. SSB voice peaks near 60 W PEP max. (Glen KD5NVC)
7.6.1 Low power output: Answer 1
Hi, Glen: It is really hard to make a reasonable guess at this distance. My first suspect would be
the output tubes, since I have had several 6146's "die slowly." The 12BY7 usually goes out
pretty quickly. (Pete AC5E)
7.6.2 Low power output: Answer 2
The TS830S runs 100 W-120 W output power, depending on the band (~120 W on the "lower"
bands, fading to about 100 W on 10 m). So, you're not far off.
You say the "bias is 60 to 65 mV," which makes no sense at all. Do you mean the idling plate
current, created by the bias, reads 60 to 65 mA? That would make sense. And if so, that's a bit
low. It's normally about 90 mA, and is adjustable with the bias control on the rear panel. If you
crank that control and cannot get the idling plate current to increase above 65 mA, then I would
definitely suspect "soft" 6146's, either one, or both. You can tell if the 12BY7A driver tube is
good by looking at the ALC meter. When in TUNE, you peak the driver tuning control (which is
grid tuning on xmit, and receiver preselect peaking on receive) for a peak in ALC reading, and
then you can adjust the drive up and down with the drive level control (potentiometer), which
only works on TUNE and CW and does nothing in the SSB mode. When in TUNE and after the
driver stage tuning is peaked, see if you can turn the drive level control up so high that the ALC
meter "pegs" (goes offscale to the right). If so, the 12BY7 is probably okay. When they go soft,
it's hard to get the ALC meter to read very high. (Steve WB2WIK/6)
7.6.3 Low power output: Answer 3
Look at the specs again. I suspect, and I may be wrong, but it may say 100 W to 180 W "input
power" on CW..... The radio transmitter being 60% to 70% efficient would come out to 60 W to
120 W output. All of the old radios measured power in the terms of input power, not output
power because that is the way the FCC power regulations of the time read....75 W input power
for a novice, and 1000 W input power for general and above. Even my Kenwood TL-922
amplifier says 2000 W input power. (Kenneth AB5CC)

19
7.7 Intermittend drop of power output
Question: …I seem to have intermittent problems with the power output. I typically would peak
the RF output in CW mode, at approximately 265 mA plate current, and see roughly 130 W
output on my less than state of the art MFJ-949E tuner. One day after a successful QSO and
excellent 59 +20 signal report from Turks and Caicos Island on 14.203 MHZ (I'm located in
Cincinnati, OH), I moved up to about 14.310 and when I tried to retune, found that I read only
about 30 W on my meter…
…After installation and neutralization of new final and driver tubes, I'm not sure if it is working
properly or not. In CW mode, at 265 mA plate current, I show about 35 W on the average
reading MFJ meter. In USB mode, if I whistle into the mike with mic level conservatively set at
about 12 o'clock (into a dummy load of course) I seem to get up to about 80 W... (Rick
W8RDH)
Answer: I had the same problem with my TS-830S. The power started dropping to 75 W, then
finally got down to 30 W. I also assumed that the final tubes were going bad, so I bought a new
pair, along with a driver and re-neutralized. Everything worked good for about a day before, I
dropped back down to 30 W. After doing some hunting around, I found that a wire that
originated by the 12BY7A tube area and ran to a pin that was insulated on the tube cage
shielding area, had a bad soldering joint. After resoldering the wire to the pin, the problem has
not come back.
Another thing you might want to look into, is that your coax jumper cable between the rig and
tuner does not have any shorts. Just recently, we were setting up a club station, and we were
only showing 30 W output from a Ten Tec Corsair II at the tuner/dummy load. Turned out to be
a bad jumper, because when it was replaced we were getting 100 W out. (Mark K9MQ)
7.8 Problem peaking Drive control
Question: The tune-up procedure for this rig begins, after setting Bias for 60 mA, with setting
the mode switch to Tune, meter switch to ALC and using the Drive control to peak. I have done
this hundreds (thousands?) of times in the past, but now when rig is switched to send, the meter
initially rises as expected, and then quickly drops to zero, with about a 30% drop in output
power as indicated on my power meter on 20 meters. Subsequent tries result in progressively
lower initial ALC readings. On 15 meters, I get no ALC indication at all, but seem to be able to
tune the Load, Plate and Drive controls for max power out. (Rick W8RDH)
Answer: Replace the 12BY7 driver tube and that should fix it. A weak driver tube will cause
low ALC action. (KF4DHE)
7.9 Intermittent loss of drive to final
Question: The rig has been out of service for a couple of years. Usually I get 1 W or less power
out. New Finals and drive tube. Occasionally works fine for hours then power goes back very
low. Meter shows NOTHING in tune position. I tried contact cleaner on switches, relays, etc.
(Jess KR4OJ)
Answer 1: I've had my used TS830 for about a year, and just encountered this symptom for the
first time. When in Tune mode and the meter switch is set to ALC, I got NOTHING on the
meter, whatever the CARRIER level setting. Then, after wiggling the DRIVE control, I saw the
ALC reading jump around. I took the cover off and sprayed contact cleaner on the variable cap's
rotor wipers. I then saw the correct ALC, but changing to CW & Ip on the meter produced
jumpy readings. I repeated the contact cleaner, which worked the second time. So check the cap
in the driver plate circuit. (John W0GMJ)

20
Answer 2: Check the driver valve base soldering under the RF board, I had the same problem
and found hair line cracks in the soldering of the base connections, also there are a couple of
resistors and a two pin plug to check right next to the base of the driver valve well if that doesn't
work check the last wafer switch, for bad contacts.
Answer 3: I found on mind this happens on the 18 MHz band along with a loss of receive on
that band. Cleaning the band-switch -- I think the last or second last wafer before the final cage
temporarily fixed the problem, and a longer lasting fix was obtained with lightly applying "Rail-
Zip" to the slider, which overcomes oxidation improving contact. This is available in model
railroading shops for improving contact on electric train tracks to the engine. (Ron 4X1MK)
7.10 No dip on the plate current and no or small output
Question: Alas... my venerable 830 serving me for the past 19 years got sick...
No dip on the plate current on any band, and just on 40 m I could get some output, but without a
dip. Changes tubes, cleaned the contacts on the bandswitch wafers (this helps for an intermittent
problem on 18 MHz, where there must be some stubborn dirt which reappears from time to
time), to no avail. (Ron 4X1MK)
Answer: With the cover off the 6146's compartment, I turn the plate tuning knob and see that
the final tune capacitor goes pretty slowly for how much I'm turning the knob... hmmmm.. that
vernier drive certainly has geared things down a lot... then... EUREKA !!!!..... I see that for a
full half revolution of the scale on the front panel, the plates only have moved maybe 20
degrees... so I tightened the two Phillips screws on the shaft coupler, which had become quite
loose over the years, aligning the plate tuning scale with the capacitor meshing, and everything
works again as it should. Very simple mechanical problem. (Ron 4X1MK)
7.11 Reducing power output to QRP-like levels, No.1
On SSB, turning down the mike gain is a very poor way to reduce output power because doing
so defeats the transmitter's ALC system. Thus, when you turn down the mike gain, you cannot
assure any particular peak output level, and you're also turning down only the voice modulation
content of your signal; the original carrier suppression, unwanted sideband suppression,
miscellaneous transmitted noise, spurious and so forth are not adjusted "down," at all, but
remain as they were. As such, signal quality overall suffers. The best way to "turn down" the
power of a TS830S - and many other rigs of that vintage that have no power level control on
SSB - is via the external ALC port on the rig's rear panel. Providing an adjustable bias level to
that port, ranging from 0 V DC to –10 V DC, will allow full-range power adjustment, down to
zero output. This is easily accomplished with a 9 V transistor radio battery (be sure to wire the
"+" battery terminal to chassis ground - the ALC voltage supplied must be negative) and a
1000 Ohm potentiometer wired as a voltage divider.
Tune up normally with the pot adjusted for zero voltage at the ALC terminal, and you should
have about 100 W output. With the key down, now turn the pot until the power falls off to
whatever power output you desire. Then, switch to SSB and your output will be that reduced
level. DO NOT RETUNE anything on the rig, its tuning will be just fine. This is the way I
adjusted to output power of my TS830S for many years, it works perfectly and still provides all
the normal audio punch and clarity, but at reduced output power. (WB2WIK/6)
7.12 Reducing power output to QRP-like levels, No.2
The MIC and CAR controls are used for adjusting power output. The meter circuit is not
especially helpful in measuring SSB power, so an outboard PEP reading wattmeter comes in