[Boatanchors] Looking for SNC Xmfr P3546 for Johnson T/R Switch

[rbethman]

On 9/23/2015 8:21 PM, Doug Hensley wrote:
> Has anyone found a suitable substitute to replace the transformer insidean EF Johnson T/R Switch ?  I'll settle for technical details if anyone hasthem.
> The one in my unit appears to be an SNC P3546.  Will send SNC an emailtomorrow but I am not optimistic they will remember this.
>
> Thanks,
> Doug W5JV
I have the docs on it.

The transformer isn't all that strange.



Those are the voltages on those tubes.



This is the transformer in the schematic.

There is one 6.2 VAC take off on the secondary for the two filaments.

The secondary is center tapped to ground, with 190VAC applied to the 
6X4, and after that, 170VDC is applied to the 6BL7.

I also have one here.  It works, and I am NOT letting it go.

They don't grow on trees, and the last one someone offered they wanted 
$200 for it!

I simply said NO THANKS!

This one I spent a whole lot less on!

It will stand up to a BC-610 that tosses a 400W carrier with today's 
voltages.

It indeed saw modulating peaks that on my peak reading Bird showed in 
excess of 2000W!

I had to throttle the audio gain on the speech amplifier, the BC-614.

It finally was kept down to less than 2000W.  Since all the circuits 
were based on 110VAC from the PE-95 10KW generator towed behind the 
communications van, seeing these higher voltages when 125 to 127VAC is 
what I see here directly from the wall.

I am using a Triplett AC Voltmeter, intended for a panel mounting, that 
reads 0 to 150.

I would say that it is pretty accurate.

I'm not going to drag the Oscilloscope to compare the two.

I haven't found a need.

Regards, Bob - N0DGN
[ Tired Old Sarge ]