[Collins] Re: Need 516F-2 replacement choke source

[Dr. Gerald N. Johnson]

On Sat, 2008-08-16 at 17:40 -0500, David wrote:
> Thanks to everyone for their helpful posts of assistance and information.
> I wanted to close the loop and leave an electronic info trail for future 
> folks seeking the same info.
> 
> Several of you referenced the Heyboer custom manufactured chokes that were 
> custom produced as a result of Mr. W. Abate's generous group offer to this 
> list awhile back.  The item number at Heyoer is : 8 Hy 6680300-00, HTS-6982.
> 
> Heyboer provided me the spec of this item as:
> "8/9 Henry choke  148 ohms 200 + mAmp  It can handle up to 550 volts. Size 
> 3" X 2 1/2" X approx 2 1/2" tall.
> One pc was quoted @ $70, 5pc @ $50 ea, 10pc @$43 as of 8/9/2008.
> 
> Mr. Abate didn't recall if this spec was the same as his order, however, he 
> agreed that this particular quoted voltage didn't sound correct.  Because of 
> this I'm leaning towards using the Hammond 193J Filter Choke
> 10H, DC Current: 200mA, Resistance: 82 ohms, Max DC Volts: 800V.  Parts 
> Express has them listed at $55.66, but of course the footprint will not be 
> the same.
> 
> Alternatively, I suppose one could isolate the choke from the chassis if one 
> went with a lower voltage rating.
> 
> Other note:  C1 is a 0.05 uF electrolytic in parallel with this L1 choke. 
> It's supposed to be resonant with the 8H choke to filter the 120Hz harmonic 
> if using a 60 Hz line.  If one substitutes the L1 choke with other values, 
> you might need to compensate the value of  C1.
> 
> Thanks again to all of those kind enough to have corresponded with me.
> 73
> -dave
> W5OC
> 
800 volts isn't enough insulation for the high voltage choke in the
516F-2 because no load the voltage floats up to about 1100.

C1 is NOT electrolytic, its paper. needs an orange drop, 1000 volt
rating. The biggest problem with its value is that depending on design
the inductance of the filter choke can change a lot as the load varies
so chasing that resonance can be a pain. That comes from the DC current
changing the flux density in the iron core.

Isolating the choke from the chassis may make marginal insulation
withstand the operating voltage but makes the power supply potentially
deadly to bugs, budgies, kittens, puppies, and people unless the choke
is totally enclosed.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer