[Amps] Amps Digest, Vol 50, Issue 17

[Garry]

amps-request at contesting.com wrote:

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>Today's Topics:
>
>   1. Re: RE :  Water Types (Colin Lamb)
>   2. Re: RE :  Water Types (Harold  Mandel)
>   3. Re: DI water explainationTSPA (Paul Christensen)
>   4. Re: RE :  Water Types (Keith Dutson)
>   5. Water Types try glycol (Kevin Adam N9IWW)
>   6. Re: cooling tubes (Roger Parsons)
>   7. Drake L4B (Jim Zellmer)
>   8. Re: 3CV1500A7 (pegasus at mho.net)
>   9. Re: 3CV1500A7 + Mods for 8877 Upgrade (Phil Clements)
>  10. Welcome back (Ian White GM3SEK)
>
>
>----------------------------------------------------------------------
>
>Message: 1
>Date: Tue, 6 Feb 2007 14:45:59 -0800 (GMT-08:00)
>From: Colin Lamb <k7fm at teleport.com>
>Subject: Re: [Amps] RE :  Water Types
>To: hermans <on4kj at skynet.be>,	"'Robert B. Bonner'" <rbonner at qro.com>,
>	amps at contesting.com
>Message-ID:
>	<14635299.1170801960376.JavaMail.root at elwamui-cypress.atl.sa.earthlink.net>
>	
>Content-Type: text/plain; charset=UTF-8
>
>"What about using a good bottle of " Dry Gin " ?"
>
>Jos always comes up with good practical questions.
>
>In fact, can't we use the amplifier itself in the distillation of some after amateur hour spirits?  Use the final amplifier to boil the mash and start the distillation process.
>
>Those hams that talk the most and longest will be rewarded with the most booze.  Isn't that the way it is supposed to work out.  
>
>Colin  K7FM
>
>
>
>
>------------------------------
>
>Message: 2
>Date: Tue, 6 Feb 2007 18:31:08 -0500
>From: "Harold  Mandel" <ka1xo at juno.com>
>Subject: Re: [Amps] RE :  Water Types
>To: "'Colin Lamb'" <k7fm at teleport.com>, <amps at contesting.com>
>Message-ID: <007f01c74a46$e1d5f490$630ca8c0 at laptopHM>
>Content-Type: text/plain;	charset="us-ascii"
>
>Okay, now that the water-quality-of-life issue is 
>agreeable with us all, let's talk about what Jos
>is saying.
>
>If pure ethyl alcohol (well, not absolute ethanol but a reasonable tincture)
>in the C2H6O family were used, would this be less conductive than
>pure water? (It's less acidic than water).
>
>After all, the manufacturers all speak about using Ethylene Glycol
>tinctures in RF loads. I wonder how ethanol in the Stanley Steamers
>and Econoloads would fare?
>
>Jos, you may have something going here....
>
>Hal
>
>[snip]
>"What about using a good bottle of " Dry Gin " ?"
>[snip]
>
>
>
>
>------------------------------
>
>Message: 3
>Date: Tue, 6 Feb 2007 19:01:07 -0500
>From: "Paul Christensen" <w9ac at arrl.net>
>Subject: Re: [Amps] DI water explainationTSPA
>To: <amps at contesting.com>
>Message-ID: <051001c74a4b$11cd0540$f9153405 at OfficeDell>
>Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>	reply-type=original
>
>  
>
>>"You don't use DI water with steel or iron piping.
>>    
>>
>Use stainless steel, brass, copper, or plastics."
>
>One point of interest with the Alpha 70V is that copper appears to be the 
>only metal that comes in contact with water.  The condenser is of a special 
>design that uses soft rosin-core solder, rather than the acid-core type that 
>is often used when bonding auto radiators.   I haven't had a good look to 
>determine if solder is also directly exposed to water.
>
>I will need to dig up the article, but I believe this was discussed by Jack 
>Quinn, author of "The Stanley Steamer," back in the May, 1966 issue of QST. 
>At the time, I believe Jack was Eimac's Product Manager.  In the article, he 
>went on to explain that even brass tubing and fittings can add to water 
>contamination over long periods of time.
>
>I almost forgot that this topic was covered by Dick Ehrhorn here on the AMPS 
>reflector nearly a decade ago.  Here's his insight on vapor cooling and he 
>even credits John Lyles in the middle:
>
>http://lists.contesting.com/_amps/1998-08/msg00030.html
>
>Paul, W9AC 
>
>
>
>------------------------------
>
>Message: 4
>Date: Tue, 6 Feb 2007 18:36:53 -0600
>From: "Keith Dutson" <kdutson at sbcglobal.net>
>Subject: Re: [Amps] RE :  Water Types
>To: <amps at contesting.com>
>Message-ID: <000a01c74a50$13e98a60$7401a8c0 at DUTSON.CORP>
>Content-Type: text/plain;	charset="us-ascii"
>
>If pure ethyl alcohol (well, not absolute ethanol but a reasonable tincture)
>in the C2H6O family were used, would this be less conductive than pure
>water? (It's less acidic than water).
>
>--------------------------------------------------
>
>Pure water has a PH of 7.0.  It is not acidic.
>
>73, Keith NM5G
>
>
>
>------------------------------
>
>Message: 5
>Date: Tue, 06 Feb 2007 19:59:43 -0500
>From: Kevin Adam N9IWW <n9iww at verizon.net>
>Subject: [Amps] Water Types try glycol
>To: Keith Dutson <kdutson at sbcglobal.net>
>Cc: amps at contesting.com
>Message-ID: <45C9247F.80700 at verizon.net>
>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>N9IWW Wrote
>Try Glycol this is used in radars for cooling
>
>
>Keith Dutson wrote:
>  
>
>>If pure ethyl alcohol (well, not absolute ethanol but a reasonable tincture)
>>in the C2H6O family were used, would this be less conductive than pure
>>water? (It's less acidic than water).
>>
>>--------------------------------------------------
>>
>>Pure water has a PH of 7.0.  It is not acidic.
>>
>>73, Keith NM5G
>>
>>_______________________________________________
>>Amps mailing list
>>Amps at contesting.com
>>http://lists.contesting.com/mailman/listinfo/amps
>>
>>  
>>    
>>
>
>
>
>------------------------------
>
>Message: 6
>Date: Wed, 7 Feb 2007 03:11:47 +0000 (GMT)
>From: Roger Parsons <ve3zi at yahoo.com>
>Subject: Re: [Amps] cooling tubes
>To: Amps <amps at contesting.com>
>Message-ID: <950669.53075.qm at web31802.mail.mud.yahoo.com>
>Content-Type: text/plain; charset=iso-8859-1
>
>I cool a single 3CX800A7 in my modified MLA2500 with a
>Papst fan which has the same dimensions as the
>original, but considerably higher output and can work
>against a higher back pressure. Works quite fine -
>exhaust air temperature always stays within limits
>even on prolonged key down. I could check the part
>number if needed, but I expect most of the major fan
>manufacturers have similar models. The down side is
>that fan noise is rather more, but still not as much
>as a normal blower.
>
>73 Roger
>VE3ZI
>
>
>
>	
>	
>		
>___________________________________________________________ 
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>
>------------------------------
>
>  
>

Jim,

Check out the "heathkitshop.com" website. They have just come out with a 
new kit with circuit board to replace the caps/diodes/resistors in the 
L-4/L-7 HV supplies.

73,
Garry - WR4R


>Message: 7
>Date: Tue, 06 Feb 2007 21:51:38 -0500
>From: Jim Zellmer <jim at ka0vsl.com>
>Subject: [Amps] Drake L4B
>To: amps at contesting.com
>Message-ID: <45C93EBA.90005 at ka0vsl.com>
>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>I recently picked up a nice L4B with power supply, SN 1934.  The tube 
>marking was pretty faded, but are Eimac 3-500Zs, date code 7115.  the 
>amp and PS are real clean and look physically pretty good.  I have 
>removed the two filter cap/ diodes boards from the PS.  I think the 
>Sprauge caps are original.  They all reformed nicely and are showing 
>less that 1 ma current at 450 volts.  I will likely change out the 
>diodes for some 3A 1KV diodes and button things up.  Are there any other 
>caveats, or issues that I should be looking for before I put this thing 
>on line.  General comments on the L4B are welcomed.  I will be using the 
>amp with my Drake B line twins.
>
>73
>
>Jim Zellmer
>KA0VSL
>
>
>------------------------------
>
>Message: 8
>Date: Tue, 6 Feb 2007 22:28:33 -0700 (MST)
>From: pegasus at mho.net
>Subject: Re: [Amps] 3CV1500A7
>To: amps at contesting.com
>Message-ID: <58789.64.58.4.46.1170826113.squirrel at b.mail.mho.net>
>Content-Type: text/plain;charset=iso-8859-1
>
>
>  
>
>>The few new tubes that exist are locked up in our safe-deposit boxes.
>>    
>>
>
>Hi Paul...
>     It might make sense to take those spare CVs out of Fort Knox and put
>filament voltage on them once in a while.  The below-mentioned W5GEL
>had a new spare that he kept handy for some 15 or 20 years. (can't
>remember exactly)  When his original failed and he put the spare in
>service it failed almost immediately.  Perhaps years of slight
>leakage that was never "getted" had allowed to much gas to build
>inside the tube.
>
>  
>
>>Modify the amp with an 8877.  "Instant-On feature is lost."  Before Bob
>>Douglas, W5GEL became SK a couple years ago,
>>he modified his 70V with the 8877 and we was very pleased with the
>>results.   And, he did the mod at near 90 years of age.
>>    
>>
>
>   As the new owner of that same amp, I'm pleased to report it is still
>working beautifully.  I had to make ONE change that Bob didn't forsee. 
>The filament transformer in the Alpha 70V was built with huge windings
>for the 30 amp current needs of the vapor tube.  It's "battery cable"
>sized heater leads are testimony to that.  The 8877 draws only 10 amps
>for it's filament.  Those large windings likely provide little useful
>internal resistance to limit start-up current. (I don't trust it's
>step-start circuit to provide a suitable slow-rise since the HV isn't
>brought on-line until the timer completes it's cycle)  It also makes it
>easier for slightly high AC mains voltage to cause the steady-state
>filament voltage to remain too high.  Such was the case with Bob's old
>amp.  He lost the filament in his first 8877 only 6 months after the
>rebuild.  He replaced it with a new one making no modifications to the
>amp.  I think he believed the tube was at fault.  He passed away a
>short time later.  Since I had pre-purchased the amp from him while
>still alive, his daughter saw to it I got the amp.  I checked the
>filament voltage and found it exceedingly high so home-brewed a
>resistor using a length of small enameled copper wire wound on a
>ceramic form.  This brought the filament voltage on the pins back down
>to just below spec.   Anyone contemplating this mod should keep that in
>mind.  Unfortunately, the compact PA-70V just doesn't have room for a
>separate filament transformer.  It's a combo transformer so one can't
>usefully alter the primary voltage to gain the desired result.  It can
>only be treated on the secondary.
>
>Take care...
>73,
>Dennis
>N0SP
>
>
>
>------------------------------
>
>Message: 9
>Date: Wed, 7 Feb 2007 00:47:42 -0600
>From: "Phil Clements" <philc at texascellnet.com>
>Subject: Re: [Amps] 3CV1500A7 + Mods for 8877 Upgrade
>To: <pegasus at mho.net>, <amps at contesting.com>
>Message-ID: <00c201c74a83$de08fa50$6501a8c0 at Phil>
>Content-Type: text/plain;	charset="us-ascii"
>
>  
>
>>   As the new owner of that same amp, I'm pleased to report it is still
>>working beautifully.  I had to make ONE change that Bob didn't forsee.
>>The filament transformer in the Alpha 70V was built with huge windings
>>for the 30 amp current needs of the vapor tube.  It's "battery cable"
>>sized heater leads are testimony to that.  The 8877 draws only 10 amps
>>for it's filament.  Those large windings likely provide little useful
>>internal resistance to limit start-up current. (I don't trust it's
>>step-start circuit to provide a suitable slow-rise since the HV isn't
>>brought on-line until the timer completes it's cycle)  It also makes it
>>easier for slightly high AC mains voltage to cause the steady-state
>>filament voltage to remain too high.  Such was the case with Bob's old
>>amp.  He lost the filament in his first 8877 only 6 months after the
>>rebuild.  He replaced it with a new one making no modifications to the
>>amp.  I think he believed the tube was at fault.  He passed away a
>>short time later.  Since I had pre-purchased the amp from him while
>>still alive, his daughter saw to it I got the amp.  I checked the
>>filament voltage and found it exceedingly high so home-brewed a
>>resistor using a length of small enameled copper wire wound on a
>>ceramic form.  This brought the filament voltage on the pins back down
>>to just below spec.   Anyone contemplating this mod should keep that in
>>mind.  Unfortunately, the compact PA-70V just doesn't have room for a
>>separate filament transformer.  It's a combo transformer so one can't
>>usefully alter the primary voltage to gain the desired result.  It can
>>only be treated on the secondary.
>>    
>>
>
>This is an Alpha problem common to many of their amps built pre-1985 that
>have a common HV-filament-control transformer. The 77DX/SX are included in
>this group. These are the ones I have experience with. I never had the
>pleasure of working on one of the "Stanley Steamers!"
>
>There are several ways to go about adjusting the filament voltage. Your
>method is one. Most surplus radio emporiums have a great selection of power
>resistors in fractions of ohms that can do the job. I discovered another
>method when doing 160 meter mods to a 77SX. I needed a filament choke to
>keep the RF out of the PS compartment anyway, so I just wound the choke with
>a wire size suitable to drop the voltage at the tube pins to just under the
>suggested value. Works great; two birds with one stone. (I love to do that!)
>
>The reason for the problem with the Alphas is that they were designed for
>230 volt mains. Hardly anyone has this anymore. My mains here are a stiff
>242 volts. In several areas of the country, folks see up to 247 volts or so.
>Guys running the Alphas that have not had this problem addressed are doomed
>to a shorter tube life. My experience with 8877's is that if operated
>according to the factory specs will last the average ham 25-30 years.
>
>(((73)))
>Phil Clements, K5PC
>
>
>
>
>
>------------------------------
>
>Message: 10
>Date: Wed, 7 Feb 2007 07:38:18 +0000
>From: Ian White GM3SEK <gm3sek at ifwtech.co.uk>
>Subject: [Amps] Welcome back
>To: amps at contesting.com
>Message-ID: <GzyEftBqHYyFFAsn at ifwtech.co.uk>
>Content-Type: text/plain;charset=us-ascii;format=flowed
>
>Paul Christensen wrote:
>  
>
>>I almost forgot that this topic was covered by Dick Ehrhorn here on the 
>>AMPS reflector nearly a decade ago.  Here's his insight on vapor 
>>cooling and he even credits John Lyles in the middle:
>>
>>http://lists.contesting.com/_amps/1998-08/msg00030.html
>>
>>    
>>
>
>Newer readers may not be aware that, about a decade ago, people like 
>Dick  Ehrhorn, John Brosnahan, John Lyles and various Eimac employees 
>were regular contributors to AMPS. Their expertise and specific product 
>knowledge are sorely missed.
>
>Welcome back to John - now, how about the others? If anyone is still in 
>contact, please think about inviting them back.
>
>
>  
>