[WSWSS] For Sale - Partially Completed 2 Meter Kilowatt Amp & Pwr Supply

Sat, 19 Jan 2002 18:09:51 -0800 (PST)

That's totally incredible!!   If ever there was a weak signal, it is that
signal that comes off the moon after a multi KW signal from the earth...
God in himmel, where have we been for the last few years?   Cliff K7RR

On Sat, 19 Jan 2002, Bob Kocisko wrote:

> Peter,
> 
> I'm doing vy weak signal work on 2m EME & soon on 70cm EME.  I'm currently
> QRP on 2m running 400 watts output.  Even with legal limit pwr, EME is the
> ultimate weak signal work in amateur radio in my opinion.  In addition, I've
> done a lot of 2m MS over long hauls & pwr is helpful for that also.  "Weak
> Signal" is not synonymous with "QRP".
> 
> 73,
> Bob, K6PF
> 
> 
> 
> ----- Original Message -----
> From: "Peter Shores" <[email protected]>
> To: "Bob Kocisko" <[email protected]>
> Sent: Saturday, January 19, 2002 2:21 PM
> Subject: Re: [WSWSS] For Sale - Partially Completed 2 Meter Kilowatt Amp &
> Pwr Supply
> 
> 
> Hi Bob,
> 
> Each  time that I read about someone selling  "high power amplifiers" on
> this reflector  I cant help but think isn't this the "weak signal society"
> group? Maybe the name should reflect something other than weak since the
> amount of energy that is going to be radiated is far from what I thought the
> term implied. However, I guess if one is doing some kind of EME or long haul
> the signal at some point is going to become weak; at least to someone
> somewhere.
> 
> 73's
> 
> Peter AD6TN
> ----- Original Message -----
> From: "Bob Kocisko" <[email protected]>
> To: "WSWSS" <[email protected]>; "Moon-Net posting msgs"
> <[email protected]>; "Forsale-Swap Net" <[email protected]>; "Bob
> Kocisko" <[email protected]>
> Sent: Friday, January 18, 2002 11:06 PM
> Subject: [WSWSS] For Sale - Partially Completed 2 Meter Kilowatt Amp & Pwr
> Supply
> 
> 
> > Hello:
> >
> > Two days ago, I posted a message that I hv for sale a partially completed
> > K2RIW design 432 MHz kilowatt amp & pwr supply.  This message pertains to
> a
> > similar situation but for 2 meters instead.  In the May 1975 QST, W9OJI
> > described a 2 meter version of the K2RIW amp using 2 x 4CX250B's in
> parallel
> > with a 0.25 WL stripline for the anode & a 0.5 WL stripline for the grid
> > ckts.  I purchased this partially completed project fm a different ham
> with
> > the intent of using much of the RF deck & many parts of the HV, screen &
> > bias supplies but rebuilding them so they will look vy professional in my
> 6
> > foot rack cabinet.  The quality of the construction of this PA & PS are no
> > where near the quality of the 432 MHz PA & PS that I offered 2 days ago.
> I
> > intended to re-build a heavy duty HV pwr supply (using the big & heavy
> xfmr
> > included), & screen, bias & filament supplies that would pwr this tetrode
> PA
> > on 2m + the 70cm tetrode PA.  I purchased this partially completed PA & PS
> > for $300 abt 4 years ago strictly for the parts & am offering it in the
> same
> > condition as when I purchased it for the same $300.  This will need to be
> a
> > pick-up only.  It's too big & heavy to ship.  Based on the value of the
> > parts alone, I think this price represents a very gud value.  I do hv a
> > couple of people in Southern Calif. interested in the 432 MHz PA & PS I
> > offered & rcv'd a couple of emails saying at $350, it was a "gift".  So,
> if
> > you're interested in this project & hv the ability & desire to complete
> it,
> > pse read on for a detailed description.  Otherwise, tnx for reading & go
> > ahead & delete this long message now.
> >
> > 73,
> > Bob, K6PF
> > DM13ar
> >
> > Detailed information for those of you who are interested follows.
> >
> > WHAT IS INCLUDED:
> >
> > The RF deck consists of two 17x7x3" aluminum chassis mounted back to back.
> > The 2 tube sockets are part of an assembled unit which was removed fm some
> > other equipment.  It is mounted along with 2 x 4CX250B's.  The 0.25 WL
> brass
> > stripline plate circuit & plate blocking cap are mfg'd & installed.  The
> > plate tuning vane (cap) is also mfg'd & mounted with a large venier & knob
> > on the exterior of the chassis.  The RFC is wound but not installed.  The
> > output coupling probe has not been made yet & the output coaxial connector
> &
> > HV connector & feedthru cap need to be installed.  The 0.5 WL brass
> > stripline for the grid ckt has bn mfg'd & installed & attached to a tuning
> > cap.  The capacitive input probe needs to be mfg'd & the tube sockets need
> 
> > to be wired up.  THe input coaxial connector, RFC & feedthru cap all need
> to
> > be installed yet.  I would estimate that the RF deck is abt 65 to 70%
> > completed.  Agn, the hard part has bn done.  A blower was not included but
> > will be needed & the airflow system will need to be completed.  The
> quality
> > of construction of the chassis (extra holes, etc) is not that pretty.  I
> > think attaching this RF deck to a rack mount panel would add a nice touch
> &
> > any extra holes in the chassis can be plugged up.
> >
> > A copy of the May 1975 QST article is included along with another article
> by
> > W2GN in October 1977 which described another version of the K2RIW PA for
> 2m.
> > That article included a pwr supply schematic.
> >
> > There is a separate 17x6x3 chassis & cover plate that has 3 meters mounted
> > on it.  One is 0-6V & labelled filaments, another meter is 0-1ma. for grid
> > current & the third meter is a 0-50ma. for screen current.  There are
> > connectors on the rear of the chassis & some interconnecting cables.  If
> the
> > RF deck is rack mounted, I think these 3 meters could all neatly be
> mounted
> > on the same panel.  Again, this chassis with the 3 meters is not vy
> pretty.
> >
> > The pwr supplies are mounted on a 17x13x3" chassis attached to a 12" rack
> > panel.  On the panel are 3 additional meters labelled 0-2.5KV plate
> voltage,
> > 0-500ma. plate current & 0-10v filament voltage.  Thr are also 2 toggle
> > switches (one is on/off & one is unlabeled), a rheostat to adjust the
> > filament voltage & a pot to adjust the grid bias.  There is another pot
> > unlabeled & not connected to anything.  Mounted on top of this chassis are
> > the HV diodes, electrolytic caps, HV metering ckt, screen supply & 2
> relays
> > (one is a time delay).  Another hvy duty relay & small xfmr(bias supply?)
> > are located underneath the chassis.  I never traced this ckt out since I
> > never intended to use this pwr supply as constructed since the quality of
> > construction was not up to my standards.  My intent was to use it as an
> xlnt
> > & inexpensive source of parts to rebuild it the way I wanted.
> Potentially,
> > all of the pwr supplies are completed but I hv no idea whether they work
> > properly or not.
> >
> > An old 36"Hx20.5"Wx15"D standard rack cabinet on castors is included.  It
> > needs paint & does not hv a rear door.  A huge plate xfmr (14"Lx9"Wx7"H)
> is
> > mounted on the bottom of the rack cabinet.  It probably weights 75-100 lbs
> &
> > needs a coat of paint also.  This xfmr is labeled 230 VAC primary & 2260V
> > secondary @ 2.1 KVA (almost 1 amp).  There are some interconnecting cables
> > included.  There are 2 of old pieces of aluminum with various holes that
> > serve as panels to fill up the space on the front of the rack cabinet.
> >
> > All of the above is being offered for $300 on a pickup only basis.
> >
> > I do hv a couple of optional item I can sell if someone is interested.  I
> > was going to build a vy well regulated HVPS using choke input filtering.
> I
> > purchased the following additional parts for the HVPS & will sell them for
> > what I paid.  THey include: 2 separate 35uf, 4KV oil filled caps that look
> > brand new ($30 each) + a used swinging choke (5-30 Hy, 750-75 ma., 10KV
> > test) for $40.  The choke also is vy heavy.  So, if interested, I will
> > include these 3 additional HVPS items for an additional $100 but they are
> an
> > option.  I won't sell them separately unless the PA & PS sell first & the
> > buyer doesn't hv an interest in these optional items.  I also was thinking
> > of using 2 x 4CX350A's instead of the 4CX250B's.  WOuld get a little
> higher
> > pwr out with higher anode voltage.  I may hv 2 or 3 of these tubes
> available
> > for sale if interested.
> >
> > I just took a few photographs & will try to get them developed on
> Saturday.
> > If they turned out ok, I should be able to email any interested parties a
> > few photos by Sunday.
> >
> > Pse let me know if you hv any interest.  Agn, if you got this far, many
> tnx
> > for reading this message.
> >
> > 73,
> > Bob, K6PF
> > DM13ar
> >
> >
> >
> > _______________________________________________
> > WSWSS mailing list
> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/wswss
> 
> 
> 
> 
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