Topband: DX-100 adventure - progress

[Charlie Cunningham]

Hi, Bill!

That's great! You're good to go with the elecrolytics, then!

BTW - as for the chirp on the signal - the DX-100 VFO  and voltage regulator
was pretty much  what they sold separately as the VF-1 vfo. The DX-40 had a
socket to power it, but I never could get rid of the chirp, until I built a
separate PS for the VFO. The OA2 gas tube just wasn't stiff enough to
eliminate the chirp. You might be able to eliminate most of the chirp by
replacing the gas tube with a Zener Diode. By the time you get up ro a 100
volts with the Zener, it's really avalanche breakdown and has a pretty stiff
knee. Might improve your chirp!

Have Fun!

73,
Charlie, K4OTV

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Bill
Cromwell
Sent: Friday, December 20, 2013 11:12 PM
To: Charlie Cunningham
Cc: 'top Band'
Subject: Re: Topband: DX-100 adventure - progress

On 12/20/2013 11:00 PM, Charlie Cunningham wrote:
> BTW, Biii - tip/suggestion  - for those series-connected electrolytics you
> probably should put a pair of equal value resistors - one across each
series
> capacitor, as the leakage currents will not be equal in each capacitor in
> each series string and the DC voltage won't divide equally across each
> capacitor unless you put individual "bleeder" or "swamping" resistors
across
> each cap in the series pair to equalize the DC across each capacitor in
the
> series!  I'll be interested to see how it turns out! I never had a DX-100
> "Benton Harbor Kilowatt"!  I did  have a DX-40 for a while, but no 160 on
> that one, though! I do have an EF Johnson Navigator in pretty good
condition
> that needs to  have all of its electrolytics replaced because of their
age.
> I does have 160 (and 11 meters also!).
>
> Good luck and Merry Christmas!
>
> 73,
> Charlie, K4OTV
>
>
Hi Charlie,

In the DX-100 there is already a big honking pair of bleeder resistors 
so that the bleeder is divided with one half across each half of the 
series pair. I think that's what you meant. The DX-100 originally had 
two caps rated at 450 volts in series and the bleeder set up that way.

73,

Bill  KU8H
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