AX 05 New CB Radio Project – PC122 into Icom IC701
AX 05 New CB Radio Project
– PC122 into Icom IC701
Most people on CB Radio running Ham or Amateur Radios usually say they are running a PC-122! I will be the only CB Radio operator running a PC-122 that looks like a ham radio! LOL
Had my old Icom IC 701 up for sale on CQDX11.com HERE.
But only a few inquiries that did not happen so decided to re-engineer it into a CB radio and pull all the IC701 parts out and sell separately.
I figured most people dont want a whole faulty ham radio for parts, just the part they need at a reasonable price. So all the internal pcbs and components are for sale by offer on CQDX11.com HERE
NOTE: PRICES NEGOTIABLE on Quantity – Will ship World wide on prior PayPal Payment.
Essentially there are seven main components [Main Case / RF HSink & Front Panel Meter NOT Inc.]
1. Double PCB with cables to front panel controls -( all cut at Switches or Pots -NOT Included.) Unsure of operation
2. LED PCB Complete – Worked Perfectly prior to removal
3. Band Switcher Solenoid Assy – Worked Perfectly prior to removal
4. PLL assy – Unsure of operation
5. BPF assy – Worked Perfectly prior to removal
6. RF Fan Assy – Worked Perfectly prior to removal
All components disassembled carefully – all plugable modules except Dual PCB assy which has all switches and pots cut from loom.
Bought a Yellow Dot Uniden PC-122 from Col, in Geelong that I thought I may be able to learn some tricks for my other two PC-122’s. Ian Barlow certainly charges well for doing his thing on CB radios, but after looking at all the mods and how well this PC-122 performs I think he gives his moneys worth.
My as new “Yellow Dotted” Uniden PC-122 has been stripped to enable integration into the Icom IC701 HF Amateur Transceiver as I have always liked the old style Military look. The large Meter which will show a proper indication of signal strength unlike the bar leds of the PC-122 is a bonus.
It looks like it will be a difficult job to do but will be worth it in the end.
I have found that the switches on the PC-122 are mounted on a PCB and will be a pain to replace into the IC701 so I may not try. As the PA/CB is ALWAYS on CB and the NB/ANL is always on NB+ANL they can stay inside the IC701 still attached the the PC-122. The MODE switch also is never moved from LSB also on my radio’s so may stay unmoved as well.
The rotary potentiometers for VOLUME/On-Off – SQUELCH – RF GAIN & CLARIFIER are a different thing as all are needed to be used. They are easily rewired to the appropriate pots on the IC701 all of which I have retained in the front panel for cosmetic reasons.
The four pot knobs and the channel selector knob were carefully levered up and the pots on the front of the PC-122 have been un-soldered. This was reasonably easy from the PCB after stripping the front fascia off and removing the PCB assy from the front escutcheon.
There will be a few unused pots on the IC701 but there is now the opportunity to add a MIC GAIN & AF GAIN or other controls to the unused pots & switches. I may try to wire the PC-122 MODE S/W to the IC701 Rotary MODE control.
11/11/2015 Lest We Forget!
Well after doing to mods over the last few days to make it all fit OK, I have placed the Uniden PC-122 into the vacant space inside the Icom IC701. After positioning it to allow room for the VFO knob to control the Channel selector which also makes room for the mini Computer power supply. This fits inside as well, so I can just plug in 240VAC to power it. The VFO assy was left in place except for the Optical Chopper and the counterweight which I may put back in after using it for a while to see if it may make the VFO feel better selecting channels.
I have used the IC701 RIT Knob for the CLARIFIER, as it stands for Recieve Incremental Tuner in a ham radio so reads as it should. The PB Tune also works to control the PC-122 SQUELCH which also is similar to Passband Tuning at a long stretch -but works fantastic and is the best SQUELCH control on any radio I have as it is so sensitive and easily set.
The dual main On/Off – Mic Gain- Comp(compression) Knob is now used as On/Off – Mic Gain – VOLUME. The Mic Gain will be wired in soon coming from the PC-122 PCB as it has no native control for Mic Gain. Not that it needs it, just to be pedantic.
The dual AF Gain – RF Gain Knob is used as RF GAIN on the PC-122 and the AF Gain is in reserve for later.
The BAND + METER + MODE + VFO Switch Knobs are not used at all at this time.
If I need to change the MODE, I can easily remove the top flap cover to access the original switches on the PC-122 front facia inside.
Testing the setup below before resetting all the knobs in place. The Kenwood MC-85 Microphone plugged in the top flap cover orig PC-122 location on faceplate. I will be running a mic cord inside to the IC701 original 4 pin socket so I can plug the MC-85 into the front of the IC701 socket to make it look original. LOL Original, yeah riiiight!
Below is the completed and operating ICOM IC701/Uniden PC-122 setup in the shak bench above my trusty old ICOM IC-R71A HF receiver that I use to monitor the ham bands etc.
In operation up and going, the RX is Awesome! Virtually no background hiss and the signals that dont move the needle that I have adjusted to about right come through loud and clear. The main Melbourne CB’ers like Squiddy and others have given me glowing reports of the audio quality and clarity and also seems to be pumping out well too.
Will put up some utube video as well so, come back soon!
Dec 2018 – 3 Years later after modification.
Still AWESOME! Especially with the Kenwood MC-85 Microphone driving it to perfection. I always get unrequested great audio reports from most new contacts either local or DX which is gratifying after all the work. Well all the work by Ken, the “Yellow Dot” man! I just made the “Plain Jane” Uniden PC-122 look pretty and great to look at to view the big analogue meter of the Icom IC701.