[R-390] R-392 quest for power - Circuit idea...

Tue, 13 Aug 2002 19:53:53 -0700

I can't speak for
the bench supply, but if that Power One is a
switcher, it will radiate all kinds of crud, loudly.
If it's a linear, I don't know, maybe that tip about
small caps across the diodes.  The manufacturers
don't worry much about RF emission.

73,
Dave Wise

> -----Original Message-----
> From: Rodney Bunt [mailto:[email protected]]
> Sent: Tuesday, August 13, 2002 7:20 PM
> To: Bruce Ussery; [email protected]
> Subject: Re: [R-390] R-392 quest for power - Circuit idea...
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> Bruce,
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> There are two pins for power on the connector
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> Power Pins A & D +24VDC, Pin E is Ground
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> One is for the fillament/heater circuit, the other is the=20
> plate B+ supply. Easy to check one
> lights the tubes!!!!
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> The B+ requirements are quite modest, so a simple 3 terminal=20
> regulator (such as a LM317 with
> heatsink) from the +30v to the B+ will give you the quiet=20
> supply that you want without much
> heat...
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> Regards,
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> Rodney
> VK2KTZ
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> --- Bruce Ussery <[email protected]> wrote:
> > Hi gang,
> > I've had this R-392 (not an A, not a Chevy), for a couple=20
> of weeks and have=20
> > been enjoying it on the kitchen counter which is also green=20
> so it looks=20
> > great. It's an actual working radio, unlike the ones I=20
> usually bring home.=20
> > All bands fairly hot, fairly accurate.
> > My only problem is finding a better way to power it. The=20
> homebrew supply=20
> > that came with it (very basic- xfmr, square bridge=20
> rectifier, 33,000 uf cap)=20
> > doesn't make any radio noise, but it has about 170 mV RMS=20
> ripple, which I=20
> > can hear on CW or SSB. It's also putting out right at 30V=20
> which worries me a=20
> > little. I've tried 2 regulated supplies; a Systron Donner=20
> bench type supply,=20
> > and a Power One open frame job. Their outputs are clean as=20
> a whistle, but=20
> > they both radiate a loud buzz into the receiver from about=20
> 8 Mhz on down.=20
> > (Too many solid state gizmos.)
> > This temporary?? kitchen setup is truly less than ideal- a=20
> 15 ft. wire=20
> > across the top of the cabinets and no ground. A temporary=20
> ground hooked from=20
> > ant. ground to the AC outlet helped the buzz some, but it's=20
> gonna take more=20
> > I think. I verified totally quiet operation with two 12V batteries.
> > I not totally against using batteries as a permanent=20
> solution- that's how I=20
> > power my "late model" ham rigs. It just gets messier having=20
> to deal with 2=20
> > batteries, lacking a 24V charger. Anyone have similar noise=20
> problems on the=20
> > lower bands?
> >=20
> > (Craf-T-Bob, this thing sounds great with a Hallicrafters=20
> R-46 speaker=20
> > hooked up instead of the LS-166/U. The R-46 has a 500 ohm=20
> xfmr according to=20
> > the label- is that correct?  Close enough for me anyway...)
> >=20
> > Bruce
> > WA4ZLK
> >=20
> >=20
> > _________________________________________________________________
> > Chat with friends online, try MSN Messenger:=20
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> >=20
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> > http://mailman.qth.net/mailman/listinfo/r-390
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