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Hey Guys, I've seen a cheap 7 digit frequency counter on ebay. I've done a few searches on the net and see mixed arguments, some say its enough others say at least 8 digits to align HF radios. Whats your opinion? This is what I'm interested in: 7 Digit counter that goes to 200mhz, no brand...

Thanks Nomad

@Dr. Frankenstein Finally got a chance to start looking at it today. Your spot on! D35 is the culprit, lifted a leg and its open. Can see the voltage stop there as well that I expect to see up in the receive chain trace R75 is connected to. Thanks for wasting your time on me. D35 is a...

Thankyou so much for your reply, that's the detail I am after. >If you understood how a radio actually works Exactly! Thats my problem for sure! :) I don't understand the fundamentals which is why I've been teaching myself online the basics to how the circuit works. I need to conceptually...

I agree its like the whole section is no getting power when on AM mode. I just seen your edited response, I should of been more clear, this radio has a RX/TX led lights only. ie not band specific lights. The RX light (green led ) works on ssb for example. So i know the Rx light is good. TX...

Well a few months have passed and I have got nowhere on this (no AM RX). I've been trying, I don't think its a solder bridge as I've checked everything over and over many times with magnifier and continuity/resistance checks to make sure everything matches the schematic.. I gave it a lot of...

Thanks Nomad, I might reverse all my solder work out briefly as I've already been over it many times comparing my work to the schematic.

I managed to get SSB RX working much better and its close to being correct on volume level (still down a bit to what it should be but receive great). I found more dry solder joints throughout the board. I can't find any more. I am still trying to get AM RX back. No RX light on AM, no volume...

Hey Guys, I'm working on what I believe is a cybernet board: PTBM146AOX with a LC7131 PLL. This radio started my interest in trying to repair radios a year ago. Bought off ebay as untested of course :) Unfortunately I didn't have the soldering skills at the time and made a lot of beginner...

There is also the use of country codes in callsigns when DXing Eg 43 Alfa Tango 001 , the 43 represents Australia, 001 is the individuals call sign. Full list of country codes: https://ukspec.tripod.com/rf/cb/divs.html I guess country codes were used more in the freeband spectrum if you...

Finally, AM carrier was low due to someone turning down VR6 (AM POWER). I just turned it back up and carrier came back to where it should be.

Thanks for clearing that up and extra detail on parasitic diodes. I've been looking at those cheap fleabay chinese component testers for a while now. Ill buy one shortly because I need that for capacitor testing as well. My cheap DMM can only read up to 20uf... Rob

@brandon7861 Thankyou so much mate for your help. Sorry for the delay in reply. Just been very busy on other things the last few weeks but I had to come back to tell you: Today I finally changed VR8 Driver 500ohm trim pot and the radio is up and running, I now have TX output!!. My first...

Thanks for the replies, I'll start working through your tests. @brandon7861 I am using Diode mode on the DVM, the C1306 is showing open between collector and Emitter when I have the black lead on collector (center pin) and red lead on emitter (right side pin). Swapping leads around also...

@brandon7861 Thanks for ideas. Still trying to work out with the 0ma driver bias issue. Tried below with no change: Lifted C215, no change. Tried cleaning and adjusting VR8, no change still 0ma. Position was 1/3 up from anti clock wise (1/3 far from most left). Replaced Driver 2SC1306 with a...

Forgot to mention. Checked radio for overall current draw while on external power supply at 13.78v On Receive: 270ma, AM transmit: 350ma, SSB transmit 440ma

@Dr Frankenstein Thanks for the detail on C149 and other schematic logic. I thought I may have seen dc volts or noise or something but after posted my online research showed RF as VAC and then I thought about it makes sense seeing D49 rectifies the signal for the front dc volt meter (signal...

Hey Guys, Thanks for the responses. @doffo I know what your talking about problems with the voltage IC, ie MB3756. All voltages are good in RX and TX on all pins. I had read about the high AM carrier problem which I'm pretty sure shows up as high voltages on MB3756. I can hear the radio key...

Thanks for the reply Nomad, on driver and final metal tab I'm getting: 13.13v on AM RX, 7.2v on AM TX 13.75v on SSB RX, 13.13v on SSB TX

Hi Guys, I bought a Realistic Navaho TRC490 recently from ebay as working on RX, but not on TX. Board is PC385AG ie same as Uniden Washington (MB8719), Cobra 2000 etc. Description was possible mic wiring wrong......mic supplied was wired wrong but I had a working mic to suit the 4 pin...