[Milsurplus] Strong Stomach Needed.

[telegrapher at att.net]

 Do you suppose this will end soon?  It's been beaten into the ground severely!  Now i'll hear about using the "delete" key.  Such is life.

Larry
W0OGH


  -------------- Original message from "Eric Winder" <ewinde at sc.rr.com>: --------------


> God, I love this list!
> 
> Eric WB4QOV
> 
> 
> 
> Date: Thu, 16 Jul 2009 19:02:44 -0500
> From: Gary Pewitt 
> Subject: Re: [Milsurplus] Strong Stomach Needed.
> To: "Bruce Lane" ,
> 	milsurplus at mailman.qth.net
> Message-ID:
> 	<200907170003.n6H03rkp003725 at mail962c35.nsolutionszone.com>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
> 
> Right on brother.   I completely agree with your
> philosophy.  Pristine original is great -if- you can do it without
> bankrupting yourself.  Modifications needed to actually use the gear
> keep a fine old rig on the air where it belongs are too.  There's a
> difference between butchering a piece of gear for no good reason and
> doing what is necessary to get it running with hopefully reversible
> mod's -if- possible .   If a piece of gear isn't so rare then I like
> to do improvements too.  I DON'T mean solid stating the whole thing
> or converting AM rigs to SSB with major mods but using better
> resistors and capacitors and solid state plug ins for the rectifier
> tubes, things that actually make it work better and last
> longer.  I've even been known to add a biscuit fan when needed if
> there's room.
> Keep what's good and fix what's bad.
> 73  Gary N9ZSV
> 
> 
> 
> 
> At 05:13 PM 7/15/2009, Bruce Lane wrote:
> >Good day,
> >
> >*********** REPLY SEPARATOR  ***********
> >
> >On 15-Jul-09 at 11:25 Michael Tauson wrote:
> >
> >         (snippage)
> >
> >I love the purists.  I really do.  Pretty
> > >much like I love a rabid pit
> >bull.  If it isn't NOS, NIB or an
> > >exceptionally close approximation,
> >it's just not worth having - or so they
> > >say.
> >
> >         (more snippage)
> >
> >At the same time, I do what I can to preserve what I can
> > >but in fully
> >functional form.  That sometimes means going in and *gasp*
> > >actually
> >having to do soldering et al.  Real work kind of stuff.
> >
> >         (final bit of snippage)
> >
> >         I have to agree, up to a point. There's absolutely nothing
> > wrong with wanting to put together an original-condition radio
> > setup from, say, the 50's or 60's. Many have already done it, and I
> > suspect many others will do it.
> >
> >         HOWEVER - When the desire to do so reaches a point of
> > bashing anyone who makes mods to a radio to make it useful for
> > their application, you're venturing into the territory of trying to
> > force your beliefs on others, and that's not a Good Thing.
> >
> >         Permit me to cite an example. I have, sitting in my garage,
> > a gorgeous Harris HF kilowatt linear amp (the RF-110A, to be
> > exact). I want to use it, but finding a means to generate the
> > necessary final plate voltage (2250VDC at an amp) has been
> > challenging. Yes, it came with a power supply, but the thing
> > requires three-phase utility input (unavailable in my area). Also,
> > the amp itself requires 100mW of drive, unmodified, which is
> > incompatible with my radios (100 watts output is typical).
> >
> >         If I were to go the "purist" route, I would probably have
> > to take out a second mortgage for Puget Sound Energy to run in a
> > polyphase feed, or get hold of a single-to-polyphase rotary
> > converter. Either way, the cost would range into the mid-to-high
> > four-figure arena, and I simply don't have the room for one of
> > those rotary monstrosities.
> >
> >         I've tried to locate the single-phase supply for this amp
> > (they're exceedingly rare), but every one I've seen went for over
> > $300 WITHOUT shipping, and they're heavy enough I'd have to shell
> > out for truck freight costs. That's over twice what I paid for the amp
> itself.
> >
> >         Even if I did go that route, I'd be surprised if I got
> > better than, say, 40% efficiency out of it. Face it, it's a
> > transformer-based design done in the late 60's/early 70's.
> > Technology has improved a bit since then. ;-)
> >
> >         The solution I found is twofold: First, for the plate
> > voltage, scrap the three-phase supply completely, and replace it
> > with a high-efficiency SMPS design I found in some back issues of
> > QEX. The entire HV plate supply will then easily run from a 240V
> > single-phase input, drawing less than 12 amps, and tip the scales
> > at around eight pounds. The remainder of the specialized supply
> > circuits in the existing power supply, such as the 400Hz source,
> > will run perfectly well off single-phase 120VAC.
> >
> >         And, getting rid of that horrendously heavy three-phase
> > potted transformer will make the power supply chassis at least 80
> > pounds lighter.
> >
> >         Second: Modify the amp itself by bypassing the driver
> > stage, and feeding the final tube directly. I've already got the
> > details on doing so tucked away on my hard drive somewhere. That
> > also eliminates at least two other voltages I'd normally have to supply.
> >
> >         In essence: What I'm doing is making good use of older
> > technology, which might otherwise have been scrapped and melted
> > down, but taking advantage of newer technology to do it. How is
> > that harmful to anything or anyone? Does the fact I can't afford to
> > use it in original/unmodified condition make me a "bad person?"
> >
> >         Looking at the bigger picture: How much power would I be
> > wasting if I tried to use it unmodified? How much extra pollution
> > might that generate from the power plant(s) supplying my part of
> > the grid? Does it not make sense to be as efficient as possible,
> > even when using older stuff? How is seeking a balance between old
> > and new wrong?
> >
> >         I'm sure there will be purists Out There who will cringe at
> > the thought of any mod to equipment like this. If so, well... I'm
> > sorry you feel that way, but at least I'm trying to put a
> > well-built piece of gear to use, in as much original shape as
> > possible, rather than stripping it down to a bare chassis and
> > building my own design into it.
> >
> >         Happy tweaking.
> >
> >
> >-=-=-=-=-=-=-=-=-=-=-=-
> >Bruce Lane, Owner & Head Hardware Heavy,
> >Blue Feather Technologies -- http://www.bluefeathertech.com
> >kyrrin (at) bluefeathertech do/t c=o=m
> >"Quid Malmborg in Plano..."
> 
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