Mrk 3 SSB Audio

[mattbee]

David, unfortunately the SSB performance on the Mark III was dismal when it was brand new, so just imagine how it is 50-years later.

Personally, if your searching for optimal SSB operation, I'd be using a new style export radio/ham radio with 11-meters on it, or a different more friendly CB that has decent SSB operations. 

These continued post in regards to the SSB performance of Browning's is like kickin' the can down the road..... unfortunately no matter what you do, I don't think you'll be happy with the performance of it regardless.

Good luck, and hopefully you'll get it working to you're satisfaction if using a different radio is not an option  

Mattbee   


 

[air1]

The MKIII was Browning's first attempt at SSB so it's not the best on SSB. It does work well on transmit though but doesn't have quite the output of most other radios. The receiver was the weak part of the system as it had no filter for the side bands making it hard to tune to frequency and keep it there. In order for it to transmit to it's full potential it needs to have all the electrolytic caps replaced if they have not been in the last 10 to 15 years. The tubes need to be tested and replaced if they are weak in any of the tests. All the resistors need to be tested and replaced if they are out of tolerance and it needs to be aligned properly. If the crystals are not close to being on frequency power output will be down but fortunately there is a VFO (clarifier) on the transmitter to help get it on frequency. Most I have worked on can do 3.5 to 4 watts on Am and about 10-12 on side band on an average reading meter if they have all this done to it. Also there are two different versions of the SSB transmitter so you have to use the correct schematics for the one you have. Same goes for the receiver.

[narfedwards2]

that i think 0.47 yellow cap tied to the 12ax7 near where the spot ties in..in the audio chain from mic input...i have had one of them create issues then go tits up altogether....

[2600]

Aug 11, 2021 13:08:23 GMT -5 narfedwards2 said:

that i think 0.47 yellow cap tied to the 12ax7 near where the spot ties in..in the audio chain from mic input...i have had one of them create issues then go tits up altogether....

A look at the ALC control between the chassis edge and the final/driver tubes might reveal trouble. Just cleaning that control can make a difference. And if it's legitimately turned down, that will limit sideband power.

The balanced-modulator transformer T1 has a tuning slug that has to be peaked for max SSB power. If someone just randomly twisted it looking for more AM power, it could be adjusted way, way off its proper peak setting. The setting of T1 won't have any effect on AM wattage. Someone randomly turning it while watching the AM wattage may have left it out in left field.

73

[Sandbagger]

Aug 11, 2021 11:50:51 GMT -5 david said:

Well I was hoping someone had documented the process. I have another unit to align, I will figure out the change to field alignment process for carrier balance. I talked to Michigan from Texas for about 15 mintues yesterday with no issues on 27.385 LSB. I just want more carrier audio for amps.

SSB has no carrier, at least none if the carrier balance is set up properly. And there isn't much you can do to improve the Browning receiver. The biggest issue with the receiver is the BFO. It drifts all over the place and requires frequent retuning to keep people sounding legible. For the mostly AM - occasional SSB operator, it might be workable. But a serious SSB'er is best served looking for a better performing SSB radio.

[2600]

Aug 16, 2021 16:49:56 GMT -5 david said:

I am lost on ALC, I know what it is, but missing what adjusts it and what tube is related to it.

Thanks for all the responses!

Only the later-production transmitters had it. Pretty sure the FCC insisted they add this feature around 1974, after it had already been in production a few years.

And if yours is the older version, no ALC there to worry about.

73