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Feeling colder??? (Hell has frozen over!!!!)

guitar_199

Sr. Member
Mar 8, 2011
984
1,322
153
Deer Park, TX
(just a "story".... not a "cry for help". I am having fun!!!)

Well... since my layoff has led to my retirement I have decided to quit "eyeballing" that Console V way up on the top shelf.

I actually recapped it about 4 years ago or so and just never got " a round tuit " when it came to getting it going. That time is here!!!!!

I pulled it down on the bench yesterday afternoon and hooked it up to the bench to see what was going on (which reminds me... I REALLY need to get rid of "work crap" and set this bench up ..... arrange it better!!!!).

Hooked it up to the generator and "no tone" came out. No transmit.

I decided to chase the "no receive" first. Setting the generator up for an S9 signal and throwing it in..... I discovered that:

The meter was dead on at the S9 mark,
When I change the channel the meter drops to zero on either side of the test channel.
When I vary the signal output... the needle follows smoothly.
When I step the attenuator UP 10 dB.... the S9 signal moves right over to the +10 spot.

This tells me that the signal is making it IN.... just.... not OUT.

It was at this point... I thought to test the "PA function". So I plugged in a speaker to the PA SPKR jack, flipped the switch to PA......
AND KABOOM!!!!!!! That TONE came flying out of the PA speaker. Dead quiet.... full loudness.

Two things......

one.... according to the OM for the Console V... flipping the PA function on DOES........ route the radio audio to the PA speaker ...IF one is hooked up. THIS is by design.

two..... looking at the schematic..... the PA switch takes the audio amp output and routes it to one of two places... in PA... straight to the PA speaker jack. In CB.... it gets sent to the RCV/TX relay so that audio only comes through in RCV, THEN it goes to the headphone jack (which has a switch). If no headphone is plugged in the audio goes to the EXT SPKR jack (which has a switch). If no external speaker is plugged in the audio is passed on to the speaker.

So.... screaming tone out the PA speaker tells me that everything else it good all the way OUT of the audio amp. Tone in PA.... tells me the sound is THERE. Nothing in CB.... tells me where I have to focus... but it all looks like "connections" at this point. Just "find and check" each of those switch points (relay, headphone jack, ext speaker jack) and see where I am losing it.

As far as transmit goes... when I key up the needle does BUMP a tiny bit... but it stays low/at the bottom. I could be wrong but the "bump" I see makes me think that SOME RF ENERGY is happening and I am guessing that I just need to drop back to the RF out section and trace it along. I will probably start back at the PLL synth and TX mixer and follow the path from there out. OR.... I will start at the mode switch and look for DC power going to the finals (including the AM regulator) to see if it is more of a power feed issue!!!!! BY THE WAY it does not transmit in ANY of ... AM, LSB, USB. THAT is why I am thinking of going back to the TX mixer first. IN SSB DC power to the driver/final is just WHAM 13.8v and everything comes down the TX strip. But still, I'll check them both.

ALSO BY THE WAY.... I did test the PA function...and it works. Mic audio DOES come out of the PA speaker. So that tells me that mic audio IS making it in, past the processing board, and into the mic amps and THROUGH the audio amp as well.

THIS IS FUN!!!!!!!!!!!

(sorry if I have put anyone to sleep. Just wanting to share the fun in the "goose chase")

[EDITED TO ADD]
I forgot to mention..... when I selected PA so that the tone would come out.... I dropped the level and found out that I can still hear tone at -117 dBm. I am hoping it will do a little better after an alignment.

AND ALSO

The fact the the channel selection appears to work properly.... I am interpreting THAT as evidence that the PLL/Synthesizer is working properly.... again... pending alignment. So hopefull ...chasing things from the VCO to the TX mixer... and "down the TX strip" will locate that missing transmit signal.
 
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That was easy!
I started at the speaker ... traced backwards.
When I got to the headphone jack on the front panel... it looked kind of funny.

I put a finger in to straighten the wires a bit.....
The shell of the headphone jack fell apart and the internal contacts fell out with the wires still soldered on. I clipped the scope probe to the metal piece that should have the signal on it..... and it DID.

So it's the old "exploding headphone jack" routine!!!!

Time to dig out the spare from under the desk.....

(edited to add)
just for a test... I found the other metal piece/contact and pushed the two of them together..... and the speaker lit off!!!!! Now to change that headphone jack....
 

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