Posts: 81
Threads: 24
Joined: Aug 2018
City: LAVERN-SUBIRATS
State, Province, Country: ESPAÑA
The output push-pull transformer is cut off. It is the transformer located next to the speaker. PUSH-PULL OUPUT TRANSFORMER, PART N. 2897.
Radio Daze, has several push-pull transformers.
Can you advise me on what goes best for 86?
Thanks.
Ferran
Posts: 7,285
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
The 125A would be suitable for your application. A pair of 71A's will make about 2W of audio. Plate load is about 5K per tube so total primary is about 10K. Secondary is going to be low like an ohm or two.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 06-12-2021, 05:51 PM by
Radioroslyn.)
Posts: 81
Threads: 24
Joined: Aug 2018
City: LAVERN-SUBIRATS
State, Province, Country: ESPAÑA
Posts: 81
Threads: 24
Joined: Aug 2018
City: LAVERN-SUBIRATS
State, Province, Country: ESPAÑA
Hello everybody,
I have finished with the restoration of the 86. I would like to mention a few points:
1.- Capacitor block: I have been very careful when removing the housing. You have to raise it a little. With a thin knife, the cables are cut between the block and the plate where the cables are welded underneath. In this way we avoid desoldering the cables and avoid damaging the board. I have put them NON-ELECTROLYTIC.
2.- The inter-stage transformer between valve 27 and valve 26, the primary was cut off. I have totally disconnected it. I have made the coupling to resistors, following the instructions in Ron's writing. Fantastic !!!!.
3.- The primary output transformer (the one below the speaker) cut off. I have replaced it with a 125A following Terry's instructions.
4.- I have carried out the calibration of the neutrodyne capacitors by means of a special coupling. One of the legs of the filament was not connected.
For the rest of the restoration ..... easy. No problem.
The radio sounds great.
Posts: 7,285
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Glad to hear you got the old guy working again!
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry