Transmitter Iron

[ka4koe]

I am, of course, researching my options for tx iron. I ran across some posts with respect to toroidal cores for transformers, etc. Is there a consensus whether or not using toroidal cores for HV transformers (2 KV secondary, 0.5A, for instance) for power supplies and mod iron???

Looking at any potential mass/cost savings.

Tnx.

FEELEEP

[N2DTS]

You can have a bc610 plate transformer I have, or a transformer and choke out of a paging transmitter, 1500/3000 volts at about 500ma.
I could also hook you up with an oil filled cap, 50 watt dale type bleeder resistors are cheap on line.

You would have to pick it up in South Jersey though.

For $100.00 I would throw in four 4-125's, a pair modulated by a pair should do about 600 watts carrier.
Likely got sockets for them and a filament transformer as well.
Plus I have some BIG variable caps...

[Detroit47]

Where did you find cheap bleeders? PLEASE SHARE A LINK. Thanks N8QPC.

[N2DTS]

Well, depends, mouser has 50k 50 watt dale type resistors, but they are only rated at 1700 volts I think.
Those are $3.00 each.

The old style bar type wire wound are $6.00 each I think.

I have a bunch of 25 watt 50k dale chassis mount bleeders in some power supplies at up to 3000 volts, I run them at 2000 mostly, been in for 30 years without a zorch.
30 years ago I did not even think about the voltage rating of those resistors...

I have them in series parallel to get the resistance and power rating I need.
You can get 25K, 50K, whatever, and up to 75 watts I think and string them together.
The 75 watt resistors have a 2000 volt rating I think.

At over 2000 volts, it might be best to use the bar resistors.
 
http://www.mouser.com/Passive-Components/Resistors/Wirewound-Resistors/_/N-7fx9f?P=1yzmno6Z1z0wncf&gclid=CK7-18yLhcMCFQIQ7AodN08AHA

$2.38 and up for all kinds of styles...

Google is great!