Monka mcHF Reference guide

Using the mcHF transciever – brief overview:
For f/w Ver. 0.0.219.26
NOTE:
If you are unfamiliar with the mcHF, please refer to the section: Before you get on the air -
Initia set-up of the mcHF transceiver” in the Operator's Manual”.
To turn on the transceiver, press the POWER button briefly and the display should light up, go through its attribution
and boot-up screen and display the frequency and spectrum scope or waterfall display.
Receive:
•Adjust volume using the ENC1 control.
•Tune the frequency using FREQ ENC knob. Select the step size using the STEP- and STEP+ buttons.
•Pressing-and-holding the STEP- or STEP+ button will temporarily decrease/increase the step size
while tuning, the step size display changing colour while this is in effect.
•Pressing-and-holding both the STEP- and STEP+ buttons at the same time will enable/disable the
Frequency Lock” mode. The main frequency display will turn grey when Frequency Lock” is
enabled. The RIT is still enabled when the frequency is locked.
•Change the band using the BND- and BND+ buttons.
•Press-and-hold the BND- and BND+ buttons simultaneously for >2 seconds to toggle between Spectrum
Scope and waterfall display modes
•Change the mode (USB, LSB, C , etc.) using button G1.
•Button G4 selects the receiver bandwidth. In FM transmit, pressing-and-holding will generate a tone burst.
•Pressing button G2 will select the mode of DSP noise reduction - Not available in FM mode.
•Pressing and ho ding button G2 will turn DSP off, saving the current settings while pressing and
holding again will restore the last-used mode. The available DSP modes are:
•NR = Noise reduction only
•NOTCH = Automatic notch (tone) filter only
•NR+NOT = Both Noise reduction and Automatic notch filter.
•If RIT is desired, use ENC3 to shift the receive frequency: The small frequency display will show actua
receive frequency display when RIT is set to non-zero, but the large display will show the transmit
frequency.
Important note: It is strongly recommended that Frequency Translation” (menu item “RX/TX Freq Xlate”) be
activated for best receiver performance – see the complete manual for more information on this setting.
Front panel controls of the mcHF transceiver

Transmit:
Set the receive frequency and mode, setting the desired output power using button G3. Note that it is recommended
that for voice modes that “full” po er not be used unless you have carefully configured for clean, linear output
po er.
Initia SSB transmit audio set-up:
•Connect the mcHF transceiver to a 50 ohm dummy load capable of handling at least 10 watts. Alternatively,
you may tune to a c ear frequency while connected to an antenna with a kno n-good 50 ohm match.
•Use button G1 to select LSB or USB mode as desired.
•Press button F2 to select the AUDio meter.
•For testing, press button G3 to select the 0.5 watt setting: The power setting does not matter for this
configuration.
•Connect the microphone to connector J3: This is is the one just above the speaker connector on the right side
of the UI board, below and to the right of the FREQ ENC control. The mcHF is typically used with an
electret-type microphone element and power for the microphone element is supplied by the radio.
•Press button M3 to switch from RIT to MIC. If the box to the right-hand side of RIT shows LIN” which
indicates that line-input mode is active, press-and-hold button M3 to change it to MIC. Press button M3 as
necessary to highlight MIC on the display: This allows the adjustment of the microphone gain.
•Now, key the radio using the Push-to-Talk (PTT) button on the microphone: The spectrum display should
freeze.
•Speak norma y into the microphone. You should see the indicator on the AUDio meter bounce upwards.
While speaking, adjust the ENC3, which adjust the MIC parameter, so that the AUDio meter indication
peaks up to +4 or so (in the red) on peaks. Occasional, higher, higher peaks are permissible, but avoid
settings that cause full-scale indications which could imply distortion.
•Release the PTT button and press button F2 to select the ALC meter.
•Press button M1 to highlight the CMP on the display: This will allow the adjustment of the compression
level of the speech processor.
•Press the PTT button and speak normally again. You should see the ALC meter indicate upwards on voice
peaks occasionally: If it does not, increase the MICrophone gain slightly.
•Adjusting CMP to a higher value will increase the aggressiveness of the speech processor: A value of 2 is a
nice, modest value and a value of 12, while very punchy” and can be used to maximize talk power” will
likely sound very processed” and may be unpleasant for normal, casual QSOs. The value of “SV” will allow
the selection of custom settings – see the full manual for additional information.
•Once you have configured the settings to your satisfaction, press-and-hold button F1 to store them in
memory.
Comment:
AM transmission operates the same way as SSB, but frequency translation mode must be activated.
Remember also that the unmodulated carrier in AM will be ¼ that of the PEP power in SSB! Because of this
the power setting in AM is automatically limited to a maximum of 2 watts.
What to do if you notice that the ALC or AUDio meters jump when you key your
microphone:
In a quiet room with an antenna or dummy load connected to the mcHF, set the METER mode to ALC and key the
microphone/transmitter without talking and note if ALC meter jumps at the instant that you key the transmitter and
goes down again. Next, switch the METER mode to AUD and key the microphone/transmitter again, watching the
AUDio meter.

If you notice that either meter jumps upwards when you key the transmitter and drops down again your keying the
transmitter may be causing either an electronic click” or mechanical clunk”, de-sensing” the transmitter's ALC.
This can be caused by the the powering-up of the electret element in the microphone when the radio is keyed and/or
by the (noisy!) mechanical action of the switch – but the result can be the same in either case: A temporary desense”
when you start talking and/or an annoying sound heard by the station receiving you!
To minimize this adjust menu item “TX Mute De ay” which will keep the microphone audio muted for a short period
after keying up. The parameters are adjustable from 0 (off) to 25, which keeps the audio muted for a full 250
milliseconds (one-quarter of a second) after the microphone is keyed.
It is recommended that one finds the minimum value to reliably suppress the appearance of the microphone key-up
noise and then increase it by 50%.
If this does not work, it may be that your microphone is taking too long to power up”. In this case disconnect the end
of R8 that connects to U1 and, instead, connect it to the 3.3 volt supply at C10-C13.
Using the mcHF with computer “Sound Card” modes via the Line-Input and Line-
Output connections:
The mcHF may be connected to a computer, tablet or smart phone via audio cables and the PTT line on the
Microphone cable to allow modes such as SSTV, PSK31, WSPR or other digital Sound Card” mode. To do this,
configure the transceiver as follows:
•Using button G1, select USB mode: All digital modes are operated using USB, regardless of band. In this
way the audio frequency of the digital signal may be added to the frequency display to calculate the actual
transmit/receive frequency.
•Set RIT to zero using ENC3: Press button M3 as necessary to highlight RIT to allow adjustment. When
using a digital mode the RIT MUST be disabled or else you will have difficulty making contacts!
•Set CMP to zero using ENC1: Press button M1 as necessary to highlight CMP to allow adjustment. When
using a digital mode, the audio compressor must be set to MINIMUM or else it may degrade the digital
signal!
•Before connecting the external device (Computer, tablet, phone) set the audio output level to mid-scale. Also
set the audio input gain to approximately mid-scale as well.
•For receive, one may use any of the available receive audio filters, but it is recommended that the 10 kHz
filter not be used! If narrow (300Hz, 500Hz or 1.8 kHz) filters are used, one may shift the center frequency
of that filter in the menu to suit the passband for that mode, but be aware that it is possible to run too narro
a filter for some of the wider” digital modes! In the vast majority of cases the 2.3kHz filter will be adequate.
Connect the Line-Input jack (J2) of the mcHF to the audio output of the device you are using to generate the audio and
connect the Line-Output jack (J1) of the mcHF to the audio input of that same device.
To key the transceiver, you will need also to connect a cable the Microphone jack (J3 on the UI board) or the Key
jack (J2 on the RF board) and the PTT/Key line on either of those jacks (the “ring”) would be grounded to key the
transceiver: Typical rig-computer interfaces will easily accommodate this connection.
•Preferably, connect the mcHF transceiver to a 50 ohm dummy load capable of handling at least 10 watts.
Alternatively, you may tune to a c ear frequency while connected to an antenna with a kno n-good 50 ohm
match.
•Using button M3, select LIN mode. You may need to press-and-hold this button to change from MIC to
LIN. Press button M3 as necessary to highlight LIN.
•Using button F2 select the AUDio meter.
•Using button G3 set the mcHF to 0.5 watts for this setup.
•Using the program running on the external device, key the computer using the selected mode. If the program

has a test” mode, use it for this.
•Adjust the LIN setting via ENC3 for a reading on the AUDio meter of +2 to +4.
•Make sure that you have set “CMP” to 0 as noted above!
•Un-key the transceiver.
•Make a note of the settings that you have used for future reference.
•Find a signal on the bands representative of the mode and adjust the audio input level of the external device
for approximately mid-scale”. The Line Output level on the mcHF on this version of firm are is fixed.
•It should be noted the the LINE OUT jack will contain the transmit audio. This is an artifact of the hardware
configuration.
•Once you have configured the settings to your satisfaction, press-and-hold button F1 to store them in
memory.
TUNE mode:
The TUNE button may be used to send an unmodulated (CW) carrier for brief testing, such as checking the RF power
output or the VSWR/matching. The TUNE function is also used for initial adjustment of various parameters (TX
Gain, Phase) as described elsewhere in detail.
The operation of the TUNE mode is very simple:
•Press the TUNE button: The mcHF transmits and the indicator turns red.
•Press the TUNE button again: The mcHF stops transmitting and the indicator turns white.
•Pressing-and-holding the TUNE button will disable/enable transmit: The on-screen TUNE” indicator will
turn grey when transmit is disabled. This is the same function as the “Transmit Disable” menu item.
Comments about the TUNE mode:
•When set to CW mode, when TUNE is activated the mcHF will produce a carrier above the dial frequency by
the amount of the setting of the “CW Side/Off Freq” (e.g. sidetone frequency).
•When set to SSB mode, when TUNE is activated the mcHF will produce a carrier that is offset from the dial
frequency by 750 Hz – the same as the audible sidetone. This carrier will be below the dial frequency in LSB
mode and above it in USB mode.
•Note: There will be no tone in SSB-TUNE mode when frequency translation is active.
•Pressing-and-holding the TUNE button will toggle the TRANSMIT DISABLE function. If this mode is on,
the TUNE indicator will turn grey and all transmit capabilities of the mcHF will be disabled. This is the
same as the parameter “Transmit Disable” in the configuration menu.
•TUNE mode does not function in AM mode.
Additiona information:
•Refer to the main manual for additional information about the Freq. Ca ibrate” menu item which is used to
calibrate the frequency display of the radio so that it reads accurately!
Configuration of the mcHF for CW operation:
•Connect a key or paddle to jack J2 on the RF board: This is the connector next to the DC power input.
For connecting a paddle for Iambic keying:
•The TIP of the connector is DIT.

•The RING of the connector is DAH.
For connecting a straight key, mechanical semi-automatic key (e.g. a “bug”) or an external keyer/computer:
•The RING of the connector keys the transmitter.
Note that the DAH/Straight Key connection is the same as the “PTT” line on the Microphone connector.
Now, press the MENU button (F1) and use the NEXT and PREV buttons (F4 and F3, respectively) to navigate to the
screen containing the menu item CW Keyer Mode”, noting the setting to the right of it. The three possible settings
are:
•IAM_A – Iambic mode A”. Using paddles, alternate dots and dashes are sent with both paddles are
depressed, stopping with the last dot or dash that was sent while the appropriate paddle was depressed.
•IAM_B – Iambic mode B”. The same as mode A” except that keying continues by sending one more
element – a dot if the paddles were released during a dash and vice-versa.
•STR_K – Straight Key. This would be used for a straight key, a bug”or external keyer/computer.
Additional items on this menu (you may need to scroll to another screen using ENC2) include:
•CW Padd e Reverse – This reverses the DIT and DAH positions of the paddle, affecting ONLY the IAMBIC
modes when using the built-in keyer and has no effect when using a straight key.
•CW TX->RX De ay – This sets the delay, after the last CW element, before the transceiver returns to receive
mode.
•CW Side/Off Freq – This sets the offset frequency and sidetone in CW operation, adjustable in 10 Hz steps.
•Important Note: If the sidetone frequency is adjusted, the center frequencies of the narrow (300 Hz
and 500 Hz) filters should be adjusted to keep the frequencies within the filter passband!
•CW TX/RX Offset – This selects whether USB or LSB is used for CW reception or if LSB is automatically
selected below 10 MHz. This also selects whether the displayed frequency is that of the transmit frequency
or that of the signal being received and whether a frequency shift occurs when switching between SSB and
CW mode: See the main manual for more information!
•The parameters CW Keyer Speed and CW Sidetone Gain are also adjustable from the main display.
( WPM” and STG”, respectively)
To configure for CW operation:
•Press button G1 to select the CW mode.
•Press button G4 to select the desired receive audio bandwidth.
•Press button G3 to set the power to 0.5 watts: The power has little effect on this adjustment.
•Press button M3 to highlight the WPM parameter: Use ENC3 to set the desired sending speed in words-per-
minute. This parameter has no effect if set to straight-key mode.
•Press button M1 to highlight the STG parameter: ENC1 is used to adjust this parameter.
•Press the paddle/key to cause the mcHF to transmit: Use ENC1 to adjust the volume of the sidetone. Note
that the volume control (“AFG”) setting has no effect on the level of the sidetone.
•Once you have configured the settings to your satisfaction, press-and-hold button F1 to store them in
memory.
Misce aneous notes and tips:
•The DSP NR” (Noise Reduction) mode may be used to advantage when in CW mode, but note that the DSP
NOTCH” mode is always disabled because it would kill” CW signals!
•The sidetone frequency is always exactly that of the amount of transmit offset from the dial frequency.
Whether or not the transmit frequency is offset from the displayed frequency or not depends on the CW

TX/RX Offset” menu parameter.
•If the parameter “CW Side/Off Freq” is changed - which changes the sidetone/offset frequency - remember
to change the the center frequencies of the 300Hz and 500Hz filters so that the center of your receive filter
passband will match your transmit frequency. If you do not do this a station that returns to you on your
frequency may do so outside the passband of your receive filter!
•There is a slight interaction between the power setting, the perceived loudness of the sidetone gain and the
sidetone gain setting. This is a known issue, but it has not been a cause of complaints.
•Pressing-and-holding button G3 when in CW, LSB or USB mode will generate a tone that is equal in
frequency to the CW sidetone and transmit-receive offset. This may be used to spot” the frequency so that
you can transmit on the same frequency as the station with which you are communicating. The loudness of
this tone may be adjusted using the Adjustment Menu” option Beep Vo ume”.
For a more thorough exp anation of the many features of the mcHF transceiver – particu ar y the items in the
menu – refer to the “mcHF Operators Manua ” that is found on the mcHF Yahoo Group in the KA7OEI fo der
of the FILES section.
In this same folder you ill also find:
•Re ease notes for the various software versions
•“mcHF_board_modifications” fi es with the recommended hardware modifications!
•Binary fi es
•Source code
Notes and tips about AM operation:
•AM transmit is possible only if Frequency Translate is active. If Frequency Translate is off, AM receive is
possible only if the signal is slightly off-tuned” to avoid the zero Hertz” hole: There are no such
restrictions when Frequency Translate is on.
•Output power is automatically limited to the 2 watt” setting when in AM mode.
•When using a wide” filter, some DSP functions may be disabled.
•Remember that AM is a continuous-carrier mode: Your final transistor heat-sinking and power supply must
be able to dissipate the power!
Notes and tips about FM operation:
•FM is disabled by default: You must enable it in the Configuration” menu.
•FM transmit or receive is possible only if Frequency Translate is active.
•When in FM mode all DSP functions are disabled.
•When in FM mode the RFG” control changes to SQL” (squelch).
•Remember that FM is a continuous-carrier mode: Your final transistor heat-sinking and power supply must
be able to dissipate the power! It is recommended that po er be reduced to the minimum required for
communications.
•If it is enabled, pressing-and-holding button G4 during FM transmit will cause a tone burst to be sent.
•The FM” indicator will turn white when the squelch is open. If tone decode is enabled, the FM” indicator
will turn red, unless the squelch is still closed (e.g. signal noisy, squelch too tight”, etc.)

mcHF Key function matrix
Button(s)
Brief press
Press-and-ho d >1 second
Power
Change display brightness
Power on and power off/save settings to memory
M1
Select AFG and CMP or STG
M2
Select RFG and DSP or NB
Switch between DSP and NB
M3
Select RIT and MIC or LIN
Switch between MIC or LIN
G1
Change operational mode
Change operational mode - including disabled mode(s)
G2
Change DSP mode
Enable/Disable DSP without changing mode
G3
Change transmit power level
Generate CW Sidetone reference (CW/LSB/USB modes only)
G4 Change receive bandwidth
(except in FM mode)
Change receive bandwidth – including disabled bandwidth(s)
Generate tone burst (FM TX only)
BAND-
Change to different band
BAND+
Change to different band
STEP-
Change step size
Temporarily change to smaller tuning step size
STEP+
Change step size
Temporarily change to larger tuning step size
STEP- & STEP+
Lock/Unlock tuning knob
POWER & BAND-
Toggle display backlight auto-off
BAND- & BAND+
Toggle Spectrum Scope and Waterfall modes
Main operationa (receive/transmit) mode:
F1
Enter MENU mode
Save settings to memory
F2
Change meter mode
F3
Toggle SPLIT mode on/off
F4
Toggle VFO A/B
Copy active VFO to inactive VFO (A=B or B=A)
F5
Toggle TUNE mode
Enable/Disable transmit toggle
Menu mode:
F1 Exit MENU mode Save settings to memory
F2 Set selected menu item to default
F3 Move to previous menu screen Move to beginning of current menu
F4 Move to next menu screen Move to end of current menu
F5 Toggle TUNE mode Enable/Disable transmit toggle
•Pressing-and-holding F1, F3 and F5 simultaneously while powering up the radio will cause defaults to be loaded.
The user must either disconnect power to retain the old settings or press-and-hold the POWER button to overwrite
them with defaults. All configurations, adjustments, frequencies and mode settings ill be lost!
•Pressing-and-holding a button (other than PO ER) while powering up the radio will cause it to enter a button
test” mode. If multiple keys are pressed, only the name of the button with the highest precedence will be
displayed. In decreasing order, the precedence is: M2, G3, G2, BNDM, G4, M3, STEPM, STEPP, M1, M3, F1,
F2, F4, BNDP, F5, G1 and POWER
•The “Band-” and “Band+” and the “Step-” and “Step+” functions may be swapped using menu selections.