RM Italy KL506 User manual

Remote Control:
The remote head is not supplied from RM Italy however the circuit diagram below shows the requirements
of creating a remote front panel if required. The connector is an RJ45 type and cable length should be no
more than 3m in length. The remote front panel controls offer the same functionality as the front panel of
the KL506.
The function of the pins present on the remote connector as as follows:
1. Ground
2. Preamplifier ON input
3. Wattmeter signal output
4. Power output for the remote command
5. Hi power input
6. Linear amplifier ON input
7. Low power input
8. SSB input
At no time should should voltage appear on pins 5 & 7 at the same time.
When using the remote control, the switches on the front panel should be set as follows:
 Preamplifier OFF
 Linear Amplifier OFF
 SSB / AM - AM Mode
 Power set to Mid, (center), position.
The digram below shows the circuit diagram of the remote control circuit and pin out of the RJ46 front
www.rmitaly.com [email protected]
Warranty:
The KL506 is covered by a 24 month warranty against manuafacturing defects, from the
date of purchase. The RF transistors, external and asthetic damage are not included in the
warranty.
Pin1 Pin 8
KL506
HF 10m Linear Amplifier
WARNING: Before using this product please read carefully all of
the information in this manual or at least the quick start guide!!! To avoid
damage or incorrect operation this is extremely important!!!
Specifications:
Operation Frequency: 10m Amateur Band, (1.8-30MHz with LPF)
Modulation Types: SSB,CW,AM, FM, (All narrowband modes)
Transistor: 4x RM SD1446 Transistor
Max I/P Current: 35A
Power Supply: 13.8VDC+/- 1V 50A
Input Fuse (Internal): 3x12A (5x20mm Fast Blow Glass Fuse)
Input RF Power: 1-10W max (All modes)
Output RF Power: 230W max CW/FM
Maximum bypass power (Amplifier off): 50W max
Input VSWR: 1.1—1.5:1
Output VSWR Maximum: 2.5:1
Harmonic Output: >-50dBc 25-30MHz
Ver 1.0 Oct. 2020

Quick Start Guide:
A more complete guide to the installation is featured later
1. Connect the RTX input connector to transceiver with
50 Ohm patch cable
2. Connect the ANT Output of the Amplifier to SWR
Bridge / Wattmeter (If required), and then the Antenna
(50 Ohm load Impedance)
3. Connect the Amplifier DC power Cable to a suitable
13.8VDC (± 1V) 50A Power Supply or Auto Battery.
Pay attention to the correct polarity
4. Make sure that the amplifier is switched off
5. Adjust the Transceivers RF output power to 7W (10W
max) if it is capable of more than 10W output
6. Switch on the Amplifier and start operating
7. Check that the antenna VSWR is acceptable with the
amplifier in use. Any large increase in VSWR indi-
cates that the Antenna is not suitable for the power
being used. Operation should be halted immediately
to avoid damage to the Amplifier / Radio / ATU etc.
Schematic Diagram KL506

Front / Rear Panel Description
Front Panel
1. Output Power Level display
2. Remote Control port
3. SSB Delay switch
4. RX Preamplifier ON /OFF Switch
5. Amplifier ON / OFF switch
6. Input Power Attenuator
7. Output Power Level LED indicator
Green Low Power
Orange Medium Power
Red High Power
8. Amplifier ON LED
9. Preamplifier ON LED
10. TX LED
1. RTX Input SO239 Connector
2. PTT Input RCA / Phono Connector (Active Low)
3. 13.8V DC Input Connector
4. Antenna Output SO239 Connector
Rear Panel

Installation:
Unpack the amplifier from it’s shipping carton and inspect for any signs of damage. The ampli-
fier should be installed (either fixed or mobile installation), in a place that allows good ventila-
tion and provides a suitable base to support it. Failure to allow for reasonable ventilation will
cause the amplifier to overheat and damage may occur. A short 50 Ohm patch lead should be
used to connect the amplifiers RTX SO239 input [connector to the output, (Antenna Socket)
of the drive Radio. This length of this cable is not critical but should be of good quality and be
kept as short as practically possible. The ANT output ^connector of the amplifier should then
be connected to antenna being used. (If an external VSWR/Power meter is to be used the ampli-
fier should be connected to the input and then the antenna to the output, This order of connection
is very important. Check also that the Antenna is suitably rated for the power output level.
(Antenna VSWR should not change much from low to high power). The antenna should be
tuned before connecting the power amplifier or with the amplifier switched OFF! .
In SSB mode the front panel switch ]should be set to SSB, if an external PTT input is not
connected. This adds a short delay to the release time of the RTX relays so that pauses in speech
do not cause the RTX relay to drop out. In AM or FM mode the SSB delay switch should be set
to AM.
The amplifier must be connected via the DC input power connector ]to a suitable power sup-
ply of the correct voltage output and sufficient current rating. The output should be 13.6 / 13.8V
DC but the amplifier may be connected to a supply from 12V to 14V DC without damage. The
current rating of the power supply must be at least 50A continuous. Be aware that the current
rating must be greater still if the drive radio is also connected to the same power supply, al-
though this is not generally advised.
The voltage output and current rating are very important for low voltage (12V) RF transistors as
voltage sag, (poor load regulation) or insufficient current capability can drastically reduce the
output power or cause distortion. If full output is not seen then the first thing to check is that the
voltage remains above 12.5V at full load. Anything less indicates the power supply is not suit-
able for the amplifier at full output.
The cross sectional area of the cables used to connect the amplifier to the PSU should not be less
than 10mm² or 7 AWG. They should also be kept as short as practicably possible to avoid volt-
age drop due to ohmic losses. This is less of a problem in a fixed installation where the power
supply may be placed close to the amplifier.
For a mobile installation the leads should not exceed a length of 3m and they should be con-
nected directly to the auto battery. An additional fuse may also be connected inline to provide
protection in case of cable short circuit to chassis ground from the amplifier to the battery.
KL506 Broadband use:
The KL505 is designed for operation on the 10m Amateur radio band, from
28.000MHz to 29.700MHz however the amplifer has useful gain covering all of
the bands from 160m to 10m, (See the diagram ‘Gain vs Frequency’ on the
previous page). The amplifier does not feature Low Pass Filtering so it is
essential if the amplifer is used on other HF bands that a suitable Low Pass
Filter is connected to the output in order to supress the harmonic output of the
band being used, to avoid unneccesary interference and comply with current
regulations which should be know to the operator before use.
It should be noted that the gain of the amplifer increases somewhat on the lower
bands so less input power is required for the same level of output power. Input
drive should be adjusted accordingly in order not to overdrive the amplifier, the
input attenuator ` may also be used to adjust the drive level so long as the
input to the amplifer does not exceed 10W. We reccomend that the amplifer be
driven with about 7W from the exciter or optimum performance on the 10m
band.

0
50
100
150
200
250
0,0 1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0
Output Power (W)
Input Power (W)
Typical Output Power KL506 10m
(28.850MHz)
KL506 Gain vs Frequency
The installation location must also provide a suitable ground system both for RF and the AC
power supply, (if used). This is very important safety requirement for any radio transmission
equipment but as power increases becomes increasingly important. A good RF ground will also
help to prevent any returned RF from causing problems with the equipment. Usually erratic
operation of equipment when in transmission may be attributed to RF being present or poor RF
grounding. Installations where a good RF ground is not possible, like operation above the
ground floor may require alternative solutions such as artificial earths or the connection of 1/4
wave counterpoises to the operating equipment. Correct RF earthing techniques are however
beyond the scope of this manual.
Mobile use should ensure that the ground connections are well bonded to the vehicle chassis
ground for best operation.
Operation:
Before using the amplifier the user must be familiar with all of the controls and be sure that it
has been connected correctly. Refer to Page 3 of this instruction manual.
Important!!
Before the amplifier is switched on, (switch _), the power output of the drive radio should be
adjusted correctly if it is capable of outputting a power greater than 10W. This may be done
with the amplifier connected but switched off. 10W is the maximum permissible input power to
the amplifier and an input power of 1-10W is OK as it is not necessary to run the amplifier at
full output if not required. Generally 7W input should be sufficient.
When the amplifier is switched on LED bis illuminated.
The amplifier does not have protection against excessive input power and as such the responsi-
bility will be with the user not to overdrive it. Maximum input should not exceed 10W. The best
performance of the amplifier will be obtained if the amplifier is operated at just less than full
output which should be achieved with about 7W input on the 10m band.
If the drive radio cannot be reduced below 10W then the input attenuator should not be used to
lower the input to the amplifier. The input attenuator can and should only be used to reduce the
output of the amplifier if required. There are 3 levels of attenuation, with LED ashowing the
currently selected level: Green Low Power, Orange Medium Power and Red Maximum Power.
Damage will occur if the amplifier is operated above 10W input power.
When the amplifier is in transmission LED dis illuminated. When it is OFF the amplifier is in
receive state.
The relative RF output level is shown on the LED display [ when the amplifier is in
transmission.

Antenna Considerations:
The amplifier is designed to work into a 50 ohms resistive load and any antenna outside of this
requirement must use an antenna tuning unit between the output of the amplifier and antenna.
It is recommended to check that the antenna to be used is sufficiently rated for at least 500W
power handling before connecting this product. It is also recommended to check that the VSWR
does not change considerably with increased power as this would indicate that the antenna was
not suitable for high power use.
Cable losses particularly increase with increasing frequency. Always use a good quality 50 Ohm
feeder and keep the length as short as possible. Not only will this allow more power to reach the
antenna but will also increase the signal strength at the receiver.
This amplifier should not be operated into mismatched loads, (high VSWR), An acceptable level
should be less than 1.5:1. Less than 2.0:1 is also acceptable but some reduction in power may be
seen and the amplifier will work less efficiently and generate more heat. There is no protection
for excessive VSWR so it is advised that the antenna is tuned correctly for the frequency it is to
used on to avoid damage to the amplifier.
Mode:
The KL506 may be used for all of the common narrow band transmission modes such as SSB,
CW,AM,FM, SSTV and data modes etc.
RX Preamplifier:
The KL506 is fitted with an RX preamplifier, that when activated can help to increase the re-
ceived signal level. This can be used when the signal level is low to help improve intelligibility
of the received signal. The RX preamp can be used independently of the amplifier however
when the amplifier and preamp are both activated the preamp is automatically switched out of
line when the amplifier is in transmission. Switch ^is used to switch the preamp on and off.
LED cis illuminated when the preamp is switched on.
Warning: Transmit Time.
Hi Duty cycle modes such as FM and Data modes etc. operate the amplifier at full power all of
the time unlike modes like SSB and CW that are either intermittent or only reach peak output for
very short times, these high duty cycle modes will run the amplifier much harder and generate
more heat in the same amount of time. It should be noted that the amplifier although capable of
being used with these modes should not be operated continuously. A transmission time of more
than a few minutes should be avoided to avoid excessive transistor junction temperature. The
exact time for transmission in these modes will depend on numerous factors such as, how good
the ventilation around the amplifier is, if there is sufficient space for freely flowing air to circu-
late, etc. If the ambient temperature is high this will reduce the total time in transmission. Com-
mon sense should be exercised, if the heat sink is becoming too hot then sufficient time should
be allowed to let it cool down before reuse.
Input drive and power output:
The amplifier should give full output with approximately 7W input. Excessive input power
should be avoided and the amplifier should always be operated in a responsible manner.
The KL506 features an input attenuator `that may be used to reduce the output of the ampli-
fier if the drive radio does not have the facility to reduce its output power.
The input attenuator should NOT however be used to reduce the input power level of the drive
radio if it is greater than 10W! Otherwise the attenuator may be damaged from overheating.
There are 3 levels of input attenuation.
Maximum output power considerations:
All amplifiers have a maximum output and this occurs shortly after gain compression where by
Pin no longer produces a proportionate increase in power output . The amplifier should always
be operated at a point below its saturated output. Trying to extract every last watt by overdriving
the amplifier will not actually help your signal to be stronger, you will in fact cause higher levels
of distortion which will make your signal less intelligible at the distant receiver station.
Running the amplifier a little under max output will also allow the amplifier to run cooler and
make it more reliable for many years of use.
As an example consider the following situation.
1 ‘S’ point on a receiver is usually approximately calibrated at 6dB so for example the difference
between S5 and S7 2 ‘S’ points is 12dB.
The difference between 7W and 230W is about 15dB a healthy increase to your signal strength,
more than 2 ‘S’ points, with the same antenna. Now lets say for example you run the amplifier at
a moderate 200W output by slightly reducing the input power, the difference between 230W and
200W is 0.6dB which when you compare this to 6 dB per S point is actually very little and as
the amplifier is not running at its absolute maximum will give a cleaner output with less distor-
tion that will actually make a difference at the distant receiver for the better!!
PTT Input:
The KL506 features a PTT input located on the rear panel \ this may or may not be
connected. If left unconnected the amplifier will still function as it uses an RF sense, (Similar to
VOX), circuit that will automatically switch the amplifier to TX when the amplifier is switched
ON and RF is applied to the input connector. The PTT input is active low, which means shorting
the center pin of the RCA/Phono socket to ground will trigger the amplifiers RTX relay. (This is
the most widely used method and the way nearly all modern transceivers are configured). The
PTT input socket requires a suitable RCA / Phono type plug and should be connected via a
screened cable to the PTT output of the transceiver. If the transceiver has a PTT output we
recommend that it be connected to the amplifier, especially for SSB operation.