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Watch this guy I listen to his videos while I'm repairing at the bench.

Ok what about the variable power control on the front of the radio does it vary the power levels when adjusted? I assume you mean the circuit board not the CPU board, Anyway there should not be 13+ volts on all three legs so I assume you have tested the (2SB754Y) this being the main modulated...

Nothing to be ashamed of you have everything you need to be efficient at component level trouble shooting there are many that have a lot less that would love to have your bench.

This is the Bench I have now this little bench does me right repaired over 200 radios and amps since we got here 2 years ago was in Indiana were here in Iowa now..

Well I didn't mean to upset the community I was merely stating that some use the word "locked" to mean the transmit frequency will always be right on 27.385 "Hopefully" drifting aside, others us "locked" to mean "Receive and Transmit" are locked together. I usually just say, Yes grasshopper we...

There seems to be different use of terminology on different posts but you are ok with Receive and Transmit frequency moving together at the same time. Just clarifying some call modifying the clarifier for equal tracking of REC & XMIT Frequency unlocked and some call it locked. Just making sure...

To troubleshoot the modulation issue, let's try removing only transistor TR24. Based on the schematic, TR24 is the only component directly linked to the microphone, so removing TR25 should not be necessary at this stage to reinstate modulation. I still could be true that TR25 circuit is at issue...

For that radio to perform its best, the alignment will be far more effective if the clarifier is modified to control both the transmit (TX) and receive (RX) frequencies simultaneously. In other words, when you adjust the clarifier, it should shift both frequencies together to keep them in sync...

I use a Rigol TS-815-TG spectrum analyzer frequently, and I'm confident you would be very happy with one. It's an incredibly powerful tool for component-level troubleshooting. Once you learn to use it with a probe to directly observe frequencies, you'll find yourself wondering, "How did I ever...

I found this format in my old teaching aids from my golden days at community college, I went ahead and modified it some it may help and i may not but I offered it anyway. If you find mistakes feel free to correct them. I will take a look at the schematic and see what could be the issue with...

I don't use this particular device but I do use a scope for this and sometimes I use a spectrum analyzer depending on what I'm trying accomplish I also have an old Heathkit VTVM that I use with an RF probe and I really like it. So there you go. I have been using these kinds of equipment for...

Ok here is a Word doc. with all that mess in it sorry didn't know I had this I have about 1500 schematics on my new Computer system and still have not had time to look at it all.

OK BELOW IS ALL THE INFO I HAVE SORRY IT'S IN SEVERAL POSTS AS IT WAS TO LONG AND I DIDN'T HAVE TIME TO BREAK IT DOWN IN ONE FILE.

AM/FM transmitter circuit The first local oscillator frequency (37MHz band) and 10.695MHz frequency generated in the Q12 are led to the Pin #4 and Pin #1 of IC3, respectively, and mixed with each other, resulting in 27MHz band transmit frequency . The 27MHz output is led to the Q8, Q9, and Q10...

AM/FM receiver circuit A received signal passes T7 , then amplified in Q2O, and again passes the band pass filter consisting of T8 and T9, then, enters into the Mixer stage of Q22. On the other hand the first Rx local signal frequency is applied to the base of Q22 through a coupling capacitor of...

Fundamental theory of PLL circuit The word PLL is an abbreciation of the "Phase Locked Loop" in which a given signal is processed to track the frequency and phase of a reference signal. In other word, the PLL is of an automatic frequency control loop or automatic phase control. The PLL circuit...

The PTBM048A0X board was used in a wide range of CB radios from various brands, including: Colt: 480, 485DX, 890, 1000, 1200 (Excalibur) Hy-Gain: 2705 (V), 2720, 2785, 3108 (VIII) Lafayette:SSB80, SSB120, SSB140 (Telsat series) Midland: 77-002, 78-976, 79-892 Cobra: Though often...

In the last 6 months I have repaired over 100 units and built several solid state amps while I could possible do more I choose not to I takes up lots of time. Going forward I plan to do a lot more but it will be a few weeks out as I have a lot of my own equipment I took in trade for partial...

Actually this is one of the easy ones to do, That being said i'm going from memory from working on thousands of radios over the years but here it goes. there is a diode D75 I do believe it needs to be removed then you need to find the wire to the fine control on the clarifier "VoiceLock" that...

I thought I did send you a message I must have screwed it up somehow.