[ARC5] Freed XFMR PGC-7 The transformer hunt continues.....

[Kenneth G. Gordon]

On 20 Aug 2014 at 7:03, Andrew Kopke wrote:

> I found it.  Any thoughts?

Yes. Several, in fact.

> Primary 115V 50/60 cps 110 VA
> Secondary 
> 650 VCT
> Choke input 225 vdc 140ma
> Cap Input 330 vdc 100ma

Or, with a full-wave bridge rectifier and choke input, 585 VDC at 56 mA 
continuous. Still 33 watts.

About 33 watts, maximum, in any case. But this is continous power output or 
CCS (Continuous Commercial Service)

> 5V 3A

Another 15 watts, not being used, since most of us don't use thermionic 
rectifiers any more for any of several reasons.

Therefore, add this wattage to the 30 watts above. Result: 45 watts.

> 6.3V 5A

Another 31.5 watts probably not being used, since you probably need to use 
either a separate 12 V or 24 V transformer for the filaments of your 
transmitter. 12 V and 24 V transformers are cheap and plentiful. If it was me, 
I'd do that.

Add this to the 45 watts above, you get 76.5 watts.

For CW, you can, generally, double the power you can pull from the 
transformer without overheating it, or in this case 153 watts, but only ICAS 
(Intermittant Commercial and Amateur Service)...in other words, CW or SSB.

Now, if you want to series the two filament windings, which will give you 11.3 
vac at 3 amps output to use as filament power, subtract 33.9 watts from that 
76.5 watts, giving you 42.6 watts continuous, or 85.2 watts ICAS.

Then, of course, as Ian pointed out, if the transformer weighs around 5 lbs, 
you can expect it to handle 100 watts ICAS. But that is total power output, 
which includes not only the HV but also the filaments.

Now you have several choices and you can decide out what to do...

Ken W7EKB