Robyn 510D no TX but good driver and final

[Zman]

I found the final choke was burnt. I replaced it and now no transmit and the final and driver are ok.. I removed both and installed them in another rig that uses 1306 and 1307 driver and final...

 

[Robb]

Pre-driver failure - don't recall the p/n.
Voltage off - AM Regulator - don't recall the p/n .
Capacitor (tantalum) - known problem - C172?

Same chassis as the Cobra 138/9 XLR - IIRC . . .

You might want to check ALL of the Service Bulletins for this radio.
I'm sure many of them are applicable:
http://www.cbtricks.com/radios/cobra/138xlr/index.htm

 

[2RT307]

I'm thinking my Cobra 139XLR base (cousin to yours) had the AM regulator die. It was a cheap and easy fix. Mike at Kilgore's Electronics said it was a very common thing with those rigs.

73,
RT307

 

[ExitThirteen]

Predriver: 2SC1973
AM Regulator: 2SC1419, but do not put another one of those in. Replace with 2SC1061 or NTE/ECG 152
C179: 2.2uf 16V tantalum capacitor, replace with 2.2uf 25V electrolytic capacitor



~Cheers~

 

[melaza]

Hi, you could use a TIP41c too. I'm starting to use the TIP series to upgrade voltage regulators.

TIP41c is a TO-220, 100V, 6A. Exit 13 is right, don't buy the original again, you could use the other one exit 13 says (2sc1061) too.

I upgraded the original 2SB754 to TIP36c on a RCI6900F and work very well.

Greeting from the Caribbean...:sneaky2: