[Milsurplus] Re: switcher noise
Ralph Cameron
ramcam at magma.ca
Wed Jun 29 14:23:43 EDT 2005
I've series connected three regulated crowbar protected 5V (nom.) 35 A
switching supplies to get 12V @35A and they run cool as acucumber at 40A
continuous for over 2 hours and they barely get warm. There is no switcher
noise I can discern and shouldn't be if properly designed.
Before series "ing" I carefull adjusted the voltage from each to 4.3V I
can't discern any voltage drop at full load. They were a bargain at a buck
apiece.
Ralph VE3BBM
----- Original Message -----
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To: <milsurplus at mailman.qth.net>
Sent: Wednesday, June 29, 2005 2:19 PM
Subject: Milsurplus Digest, Vol 14, Issue 58
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> Today's Topics:
>
> 1. Re: GB> Re: Time to put your jammers on (Hue Miller)
> 2. Re: GB> Re: Time to put your jammers on (Brad Thompson)
> 3. RE: RAK-7 / RAL-7 (Kenneth G. Gordon)
> 4. T-195 power supply (flood at Krohne.com)
> 5. Re: Choke identity sought. (Kenneth G. Gordon)
> 6. Re: RAK-7 / RAL-7 (WA5CAB at cs.com)
> 7. Re: T-195 power supply (David Stinson)
> 8. Re: T-195 power supply (W7QHO at aol.com)
> 9. Re: T-195 power supply (David Stinson)
> 10. Re: [ARC5] Re: [Milsurplus] Re: Antenna tricks
> (Unserviceable but Repairable)
> 11. Re: [ARC5] Re: [Milsurplus] Re: Antenna tricks (David Stinson)
> 12. Re: [ARC5] Re: [Milsurplus] Re: Antenna tricks (James Duffer)
> 13. Re: [ARC5] Re: [Milsurplus] Re: Antenna tricks (Richard Brunner)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 29 Jun 2005 01:36:00 -0700
> From: "Hue Miller" <kargo_cult at msn.com>
> Subject: [Milsurplus] Re: GB> Re: Time to put your jammers on
> To: <glowbugs at piobaire.mines.uidaho.edu>, <milsurplus at mailman.qth.net>
> Message-ID: <BAY106-DAV79FF97127FBA2097FAC31E4E00 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
>
> I still have a couple of these beasts, an ARQ-1 and an ARQ-8. I was
> just thinking, it would be non-trivial to power these up, considering
> the usual 400 Hz requirement, but it might be interesting to see what
> the jamming signal sounded and looked like. -Hue Miller
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 28 Jun 2005 22:36:54 -0400
> From: Brad Thompson <Brad.Thompson at valley.net>
> Subject: [Milsurplus] Re: GB> Re: Time to put your jammers on
> To: Tom Norris <r390a at bellsouth.net>,
> glowbugs at piobaire.mines.uidaho.edu
> Cc: milsurplus at mailman.qth.net
> Message-ID: <5.0.2.1.2.20050628222155.0242b520 at pop.VALLEY.net>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> At 09:02 PM 6/28/05 -0500, Tom Norris wrote:
>>In no particular order --
>>
>>The output tubes are Western Electric 703A
>>Spec page for the tubes here
>>http://www.hts-homepage.de/WesternElectric/WE703A.html
>>
>>Code name apparently for this set was "Rug"
>>During the Normandy Invasion 240 of these,
>>along with another 200 higher power jammers
>>were successful in jamming any German radar
>>installations or radar guided guns.
>>
>>With that power supply, it *may* (or may not)
>>be a UPT-T4 APQ-2 trainer. May be why the
>>ps looks so neat. The trainer is a hella more rare
>>that the everyday T-9 I can't find any documented
>>differences, other that the statement that the trainer
>>was "modified" Only accessory listed with the trainer
>>is the AS-263/UPT antenna, as with the regular jammer.
>>
>>Now if I can remember the dozen sites where I found
>>all that info! Seems I didn't bookmark them!
>
> Hi, Tom and the group--
>
> Here's one:
>
> http://pages.cthome.net/fwc/APT-EQP.HTM
>
> BTW, this has to be one of the most interesting sites I've stumbled
> across-- where else
> will you find treatises and lists on topics ranging from bullfrog raising,
> to infant mortality in
> New England, to cast-zinc statues, to World War II radio, radar, and
> crypto
> equipment?
> Don't visit this site unless you have a couple of extra hours to spend on
> it!
>
> 73--
>
> Brad AA1IP
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 29 Jun 2005 07:23:13 -0700
> From: "Kenneth G. Gordon" <kgordon at moscow.com>
> Subject: RE: [Milsurplus] RAK-7 / RAL-7
> To: Milsurplus at mailman.qth.net, "Ed Zeranski" <ezeran at ezeran.cnc.net>
> Message-ID: <42C24C61.6443.1C2B1990 at localhost>
> Content-Type: text/plain; charset=US-ASCII
>
> Ed Zeranski wrote:
>
>> As an aside..In one of the Navy manuals I got for the RAL, there is a
>> manual for
>> RAK and RAL and one covering both, there was a D or E sized drawing of
>> the RAL
>> schematic with the tubes replaced by FETS. The drawing looks officially
>> done
>> with info block etc...just like real! So, FETS were what, early '70s? I
>> just
>> wonder if one was ever converted.
>
> I have seen that...somewhere. I may even have a copy of it.
>
> I have several RAKs in which that was done. Whoever did it, also removed
> the audio tuning network....completely. However, I think this was done by
> one of the other guys who worked for my former employer who "left" me all
> the stuff. I have not yet tried one of these out to see how it worked.
>
> Ken W7EKB
>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 29 Jun 2005 10:32:25 -0400
> From: flood at Krohne.com
> Subject: [Milsurplus] T-195 power supply
> To: milsurplus at mailman.qth.net
> Message-ID:
> <OF29E09354.0216C5F2-ON8525702F.004E967E-8525702F.004FDF65 at Krohne.com>
> Content-Type: text/plain; charset="US-ASCII"
>
> Greetings,
>
> I have come into a large number of 24-28VDC 60 amp power supplies. These
> are switching supplies pulled out of 250-500 Watt 900MHz paging
> transmitters. My thoughts went to using these as a power supply for the
> T-195 transmitter I picked up this spring. Have any of you out there used
> something similar. I was worried about switching noise. I have a very
> quiet switcher running the R392 now.
>
> Also, it's a bit off track but is anyone interested in 500 watt Glenair
> PA's for 900MHz? Perhaps you could use them to cook birds nesting on your
> hf arrays?
>
> John Flood KB1FQG
> TASC Department
> KROHNE, Inc
> 7 Dearborn Rd.
> Peabody, MA 01960
> Tel.: 978-535-6060 / 800-356-9464
> Fax: 978-535-8180
>
> ------------------------------
>
> Message: 5
> Date: Wed, 29 Jun 2005 07:33:50 -0700
> From: "Kenneth G. Gordon" <kgordon at moscow.com>
> Subject: Re: [Milsurplus] Choke identity sought.
> To: Milsurplus at mailman.qth.net
> Message-ID: <42C24EDE.25115.1C34D591 at localhost>
> Content-Type: text/plain; charset=US-ASCII
>
>> > SC-1019 (ES-700683) RETARDATION COIL 3340-308 708 060
>
> Actually, I think this info above concerns a "telephone loading coil", but
> these devices ARE a power supply choke. Possibly severe mislabling
> by someone a LOOONG time ago. I think these originally came from
> Fair Radio Sales back in the 1970s.
>
> Ken W7EKB
>
>
> ------------------------------
>
> Message: 6
> Date: Wed, 29 Jun 2005 10:38:49 EDT
> From: WA5CAB at cs.com
> Subject: Re: [Milsurplus] RAK-7 / RAL-7
> To: ezeran at ezeran.cnc.net, Milsurplus at mailman.qth.net
> Message-ID: <6d.48424189.2ff40c79 at cs.com>
> Content-Type: text/plain; charset="US-ASCII"
>
> I don't have enough of a sample of the RAK, RAL and/or RAK/RAL manuals to
> say
> but I wonder whether some of the model numbers indicate the same thing
> that
> they did with the RBB/RBC? I.e., the RBB/RBC-5 and RBB/RBC-6 are
> identical
> except that one was supplied in a table mount cabinet and the other was
> rack
> mounted.
>
> In a message dated 6/29/2005 12:47:14 AM Central Daylight Time,
> ezeran at ezeran.cnc.net writes:
>> Right. Once a LONG time ago, I made a rack mount version of an RAK-
>> 7 for an employer by doing just that. Looked factory stock when I got
>> finished.
>>
>
> Robert & Susan Downs - Houston
> <http://www.wa5cab.com> (Web Store)
> MVPA 9480
> <wa5cab at cs.com> (Primary email)
> <wa5cab at houston.rr.com> (Backup email)
>
>
> ------------------------------
>
> Message: 7
> Date: Wed, 29 Jun 2005 10:11:01 -0500
> From: David Stinson <arc5 at ix.netcom.com>
> Subject: Re: [Milsurplus] T-195 power supply
> To: flood at Krohne.com
> Cc: milsurplus at mailman.qth.net
> Message-ID: <42C2BA05.7090705 at ix.netcom.com>
> Content-Type: text/plain; charset=us-ascii; format=flowed
>
> I may be interested, depending on price/size etc.
> I have an ASTEC switcher running my SCR-287
> (75 amp surge to start the dynamotor) and
> it's RF quiet. Can the 900 MC rigs be
> "tweaked" into the ham range, you think?
>
>
> flood at Krohne.com wrote:
>> Greetings,
>>
>> I have come into a large number of 24-28VDC 60 amp power supplies. These
>> are switching supplies
>
>
> ------------------------------
>
> Message: 8
> Date: Wed, 29 Jun 2005 11:11:23 EDT
> From: W7QHO at aol.com
> Subject: Re: [Milsurplus] T-195 power supply
> To: flood at Krohne.com, milsurplus at mailman.qth.net
> Message-ID: <9a.29181984.2ff4141b at aol.com>
> Content-Type: text/plain; charset="ISO-8859-1"
>
>
> In a message dated 6/29/05 7:32:50 AM, flood at Krohne.com writes:
>
>
>> I have come into a large number of 24-28VDC 60 amp power supplies. These
>> are switching supplies pulled out of 250-500 Watt 900MHz paging
>> transmitters. My thoughts went to using these as a power supply for the
>> T-195 transmitter I picked up this spring. Have any of you out there used
>> something similar. I was worried about switching noise. I have a very
>> quiet switcher running the R392 now.
>>
>
> On the noise question, turn one on next to a receiver, tune around and
> take a
> listen.
>
> As to using your switcher to run a T-195, depends on whether or not your
> set
> has the solid state replacements for both internal dynamotors. The
> electromechanical dynamotors, especially the 1000 volt unit, require a
> power supply
> capable of providing a high starting current surge (couple of hundred amps
> for a
> few milliseconds). Switching power supplies generally aren't capable of
> providing this. One solution here would be to "float" a couple of 12
> volt car
> batteries in series across the output to take the surge.
>
> A number of T-195's I've seen have a solid state 1000 volt supply and a
> dynamotor to supply the lower voltages. Your switcher alone might run
> this
> combination, but you would have to try and see.
>
> Would be interested in one of your switchers.
>
> Dennis D. W7QHO
> Glendale, CA
>
>
> ------------------------------
>
> Message: 9
> Date: Wed, 29 Jun 2005 10:17:48 -0500
> From: David Stinson <arc5 at ix.netcom.com>
> Subject: Re: [Milsurplus] T-195 power supply
> To: W7QHO at aol.com
> Cc: flood at Krohne.com, milsurplus at mailman.qth.net
> Message-ID: <42C2BB9C.9060600 at ix.netcom.com>
> Content-Type: text/plain; charset=us-ascii; format=flowed
>
>
>>>I have come into a large number of 24-28VDC 60 amp power supplies. These
>>>are switching supplies
>
> I run my SCR-287 (75 amp surge) and SCR-274N (~50 amp surge)
> on ASTEC switching supplies. One is a dual 50 amp and the
> other is a dual 30 amp. They have a pin on the control connector
> that allows you to force load sharing, as long as you set
> the output voltages identically. The one running the SCR-274N
> has a couple of "starting caps" hung on the outside to
> help the surge along, but the "big-un" starts the
> PE-73 without any trouble.
> Both supplies are RF quiet. I initially hung
> some large ferrites on the "ins and outs,"
> but only because I was in a hurry and as "insurance."
> Afterwards, I pulled them off and found that they
> weren't needed. If you find yours noisey try some ferrite.
>
> I'd also be interested in one or two, if the price
> is right.
>
> 73 Dave S.
>
>
>
> ------------------------------
>
> Message: 10
> Date: Wed, 29 Jun 2005 11:55:54 -0400 (EDT)
> From: Unserviceable but Repairable <cosmoline at ba-watch.org>
> Subject: Re: [ARC5] Re: [Milsurplus] Re: Antenna tricks
> To: brianclarke01 at optusnet.com.au, nerd at verizon.net
> Cc: arc5 at mailman.qth.net, k2gkk at hotmail.com,
> milsurplus at mailman.qth.net
> Message-ID: <200506291555.j5TFtsLj012172 at fracas.netboobie.org>
>
>> dead bug on the whip's tip ball
>
> D'ya think, Mac, your antenna might have still been whupping back 'n
> forth as Brother Dave described in the story of "Miss Baby & the
> Motorcycle Jacket?"
>
> You probably know story where B-Dave imitated sound made by State
> Patrolman's antenna as it came to rest after a sudden stop.
>
> Whuuup-whuuup-whuup
>
> Consider one such whuuups dead centering the bug
>
> Sure simpler than doing the math for E-field. Might provide
> a graceful withdrawl from the RF bug-zap
>
>
> ------------------------------
>
> Message: 11
> Date: Wed, 29 Jun 2005 11:30:24 -0500
> From: David Stinson <arc5 at ix.netcom.com>
> Subject: Re: [ARC5] Re: [Milsurplus] Re: Antenna tricks
> To: Unserviceable but Repairable <cosmoline at ba-watch.org>
> Cc: arc5 at mailman.qth.net, brianclarke01 at optusnet.com.au,
> k2gkk at hotmail.com, milsurplus at mailman.qth.net
> Message-ID: <42C2CCA0.5080103 at ix.netcom.com>
> Content-Type: text/plain; charset=us-ascii; format=flowed
>
> Guys:
>
> I don't think the facts or fancy of the story are worth
> making an enemy by calling someone "liar" in public.
> We should not make enemies over trifles.
>
> The man told me he saw it.
> I can't prove he didn't. I can do math,
> but there's no way I can know every factor,
> because I wasn't there. It's "impossible" to
> break a window with a Nerf football, too.
> But I've seen it done.
>
> It's no skin off our behinds one way or the other.
> When your hide isn't at stake, isn't it better to
> concede the "benefit of the doubt," then make
> an enemy for little reason and no profit?
>
> It's not like we're doing research to solve some
> big problem.
> It's a good story; one you can tell over beer and pizza
> and everyone gets a chuckle and goes on.
> I agree with a paraphrased Harry Truman:
>
> "Damn an expert anyway!
> They sure know how to ruin a good story."
>
> 73 Dave S.
>
>
>
>
> ------------------------------
>
> Message: 12
> Date: Wed, 29 Jun 2005 11:51:12 -0500
> From: "James Duffer" <dufferjames at hotmail.com>
> Subject: Re: [ARC5] Re: [Milsurplus] Re: Antenna tricks
> To: arc5 at ix.netcom.com
> Cc: milsurplus at mailman.qth.net
> Message-ID: <BAY17-F5E2A9AE082C8DA62F571BB9E00 at phx.gbl>
> Content-Type: text/plain; format=flowed
>
>
> snip.
>>It's a good story; one you can tell over beer and pizza
>>and everyone gets a chuckle and goes on.
>>I agree with a paraphrased Harry Truman:
>>
>> "Damn an expert anyway!
>> They sure know how to ruin a good story."
>>
>>73 Dave S.
>
> And the definition of an expert can be obtained by breaking the word down
> into its two parts, "ex", a has been, "spurt", a drip under pressure.
> Thats
> it, a has been under pressure!!
>
> 73, Jim
>
>
>
>
> ------------------------------
>
> Message: 13
> Date: Wed, 29 Jun 2005 14:02:30 -0400
> From: "Richard Brunner" <rbrunner at gis.net>
> Subject: Re: [ARC5] Re: [Milsurplus] Re: Antenna tricks
> To: <milsurplus at mailman.qth.net>
> Message-ID: <01e801c57cd5$c17cd870$53c907cf at richardb>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=response
>
> Well, there are experts and there are experts; try this.
> The end of the antenna is a high voltage point, and is indeed a sort of
> mechanical point. As we all know, where you have a high voltage at a
> point,
> there is a very high voltage gradient through the air. It's reasonable
> that the voltage gradient was sufficient to snuff the poor 'ole bug. Note
> also that a neon lamp attached to the end of the antenna will also light,
> BECAUSE OF THE HIGH VOLTAGE GRADIENT. You don't need a ground
> connection...
> Note that high voltage equipment uses rounded guards to reduce the voltage
> gradient to reduce or eliminate corona when the air breaks down from the
> high voltage gradient. As supporting evidence, (about high voltage
> gradient) in high voltage switchyards everything touchable is grounded,
> because if left floating it will assume a potential somewhere between the
> line voltage and ground, and when you touch it it is very unpleasant.
>
> Richard Brunner, AA1P
>
>
>
> ------------------------------
>
> ______________________________________________________________
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