[Boatanchors] Re: [Hallicrafters] various

[James A. (Andy) Moorer]

I guess I would have to respectfully disagree - the 5U4 filament pulls 3 
amps whereas the GZ34 filament only pulls 2 amps. That extra amp can heat up 
the power transformer a bit (5 watts to be precise). Most transformers will 
tolerate 50% more current, but on others it will shorten the transformer 
life and can even drip nasty black stuff out the bottom.

I suggest replacing it with 1N4007 diodes in series with a 50-ohm 20-watt 
resistor. That gives just about exactly the same V-I curve. Some folks skip 
the resistor, but that makes the voltage a bit high.

James A. (Andy) Moorer
www.jamminpower.com

----- Original Message ----- 

> Hi Jeff - I have replaced 5AR4's with 5U4GB's in a number pieces of 
> equipment due to the cost of 5AR4's. I did not re-wire the socket. The 
> pinout is the same. Electrical specs are close enough.
>
> Dave N7RK