Highs

[Shadetree Mechanic]

Here is the current info that I just dug up. Basically what I had in my notes with info on the AM modulation transformer. As was said earlier, the modulation transformer in these radios is barely adequate to run the radio in its stock form. There is a limit to the amount of lows you can add before excessive heating of the transformer becomes a problem. If the radio has increased audio, expect the audio chip to get hot as well as the regulator. I usually leave the transmit audio alone and boost the audio chips gain. I also leave the Finals alone save for a swing kit and run an Astatic 636. Enough lows, but not more than the radio can handle. I am not worried about power because I run amplifiers. The receive I will open up to the full Goldfinger values and run a speaker from a bookshelf stereo system.

Use at your own risk.
https://www.wwpdx.com/ForumWWPDX/viewtopic.php?f=117&t=13845&sid=c7ea547054d6f6001c1be8995c3a43ea

 

[543_Dallas]

I think it could do much better with the modified Heising set up. As it is the final and driver draw DC current through the mod transformer. Get rid of the DC on the transformer and it only has to deal with the audio. B+ would be supplied through a reactor (choke). I think that little transformer has potential not when carrying enough DC to make 12 Burdd Whatts.

https://www.amwindow.org/tech/htm/modheising.htm

 

[Shadetree Mechanic]

More info.
https://www.worldwidedx.com/threads/29-ltd-audio-boost-help.36793/

 

[Bow]

On a Cobra 29, the Modulation transformer saturates at around 200-250 Hz... The wave form looks all jacked up, and the Audio turns to Poo

That is on TX and RX.

 

[Tokin]

Ill leave this here. Best $180 i ever spent.