[Milsurplus] Milsurplus Digest, Vol 112, Issue 40
RUSTY CORBIN
rusty4248 at nwcable.net
Thu Aug 22 14:39:26 EDT 2013
----- Original Message -----
Send Milsurplus mailing list submissions to
milsurplus at mailman.qth.net
To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/milsurplus
or, via email, send a message with subject or body 'help' to
milsurplus-request at mailman.qth.net
You can reach the person managing the list at
milsurplus-owner at mailman.qth.net
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Milsurplus digest..."
Today's Topics:
1. Re: Copper oxide rectifiers (C.Whitaker)
2. Re: Copper Oxide rectifiers (COURYHOUSE at aol.com)
3. MC-385-A & CQ mags (telegrapher at q.com)
4. manuals free to a good home (Nick England)
----------------------------------------------------------------------
Message: 1
Date: Wed, 21 Aug 2013 13:07:02 -0400
From: "C.Whitaker" <whitaker at pa.net>
To: milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] Copper oxide rectifiers
Message-ID: <5214F3B6.5050406 at pa.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
de WB2CPN
Wayne,
From reading the replies you are getting, I decided to not replace (update)
the copper-oxide bridge rectifier which is in a 24 Volt DC supply someone
had built a long time ago for the little LF receiver I came into.
I was going to use contemporary diodes. Now I'll leave it alone.
I did replace the big capacitor, although it tests OK.
73 Clete
++++++++++++++++++++++++++++++++++++++++
On 8/20/2013 9:10 PM, hwhall at compuserve.com wrote:
> Does anyone have experience with copper oxide rectifier stacks? I'm helping with a Link Trainer restoration project for a local museum and there are two such in the instructor's control chassis. Approx 1940s vintage. Do these things fail easily or might these be usable still?
>
>
> Thanks!
>
> Wayne
> WB4OGM
>
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
------------------------------
Message: 2
Date: Wed, 21 Aug 2013 15:54:12 -0400 (EDT)
From: COURYHOUSE at aol.com
To: hwhall at compuserve.com, w5jv at hotmail.com,
milsurplus at mailman.qth.net, boatanchors at mailman.qth.net
Subject: Re: [Milsurplus] Copper Oxide rectifiers
Message-ID: <31f16.3324137.3f4674e4 at aol.com>
Content-Type: text/plain; charset="US-ASCII"
lets try one in a crystal set as a detector!
Ed#
In a message dated 8/21/2013 12:50:47 P.M. Mountain Standard Time,
hwhall at compuserve.com writes:
Thanks for the notes, John. Good info. Between what you sent and
experience info from Bruce, KA2IVY, I think we will give these things a chance to
stay in circuit. I'll remove them and test them when I get into their part of
the works, just to be sure, before we apply power to the system.
Thanks to all!
Wayne
WB4OGM
-----Original Message-----
From: John Hensley <w5jv at hotmail.com>
To: hwhall <hwhall at compuserve.com>; MilSurplus QSLNet
<milsurplus at mailman.qth.net>
Sent: Tue, Aug 20, 2013 7:23 pm
Subject: Copper Oxide rectifiers
Copper Oxide rectifiers were used by many companies for a time. ?Western
Electric made teletype loop supplies using them and Lionel made their train
operating transformers using them. ?Here is some information that I have
collected:
This is a robust rectifier design offering full recovery when allowed to
cool after overload. ?From the General Electric Company Electronics
Department, booklet #175-3012A THE ABCs of RADIO (copyright-1943):
"The copper oxide rectifier is made in the form of a copper disk, coated
on one side by a layer of copper oxide. The copper oxide is plated with
nickel to allow good external circuit contact. The juncture of the oxide and
copper offers a low resistance to the flow of current from the oxide to the
copper, but a high resistance to the flow of current in the reverse
direction. The detailed operation of this device is complex, but in general it
involves the formation of thin films at the junction of the oxide and copper in
which the molecules are so polarized that the transfer of electrons in one
direction requires much less work than a similar transfer in the opposite
direction.
Copper oxide rectifiers possess a definite breakdown voltage and breakdown
temperature. If either critical value is exceeded, the rectifier will pass
current freely in both directions. After the unit is cooled or the high
voltage removed, it will immediately function again as though it had not been
overloaded." ?<-->
?
Hope this gets you started,
John W5JV
______________________________________________________________
Milsurplus mailing list
Home: http://mailman.qth.net/mailman/listinfo/milsurplus
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Milsurplus at mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
------------------------------
Message: 3
Date: Wed, 21 Aug 2013 17:28:00 -0400 (EDT)
From: telegrapher at q.com
To: milsurplus <milsurplus at mailman.qth.net>
Subject: [Milsurplus] MC-385-A & CQ mags
Message-ID:
<364726938.1869587.1377120480609.JavaMail.root at md33.quartz.synacor.com>
Content-Type: text/plain; charset=utf-8
What a coincidence. I pulled a bunch of CQ mags in from the shed to see what i had. In one of the 1951 issues was an ad by ESSE that offered them for $.19. A few pages later another outfit had them for $.25. What a ripoff! They gave a description of what it was used for and what the impedance's were that it interfaced to.
Lotta cheap stuff in those ads. For one a BC-306 antenna box for $2.95. Good thing i wasn't in any sort of financial position to buy that stuff. But, boy would i like to have been able to buy that stuff. To young to know anything about it.
I pulled one box out of the shed that said CQ magazines on it. What i had in there was 1941 all but Nov., 1955, complete year and 1956 all issues but Feb. Since the years were tied into a bundle i have to think that those all the issues i have for those years.
But wait! There will be more boxes surfacing in the near future. 50 cents an issue of $5 per year. seems reasonable. I can probably cram all 3 years into a Mid sized USPS Medium Flat rate box for $11, Less than that i would have to box or put in a manila envelope if your wanting only a issue or two.
Larry
W0OGH
Nick: I have a 30' by 40' pole building that I have converted into a personal library of military related items. I am mostly interested in WWII radio communications related items. I enjpy letting interested indivuals come and read the materials I have in my collection. It is my near future to be able to travel to schools and other community events to make as many people aware of the many, many contruubitions the our service personnel made to keep our many privaleges free. I give thanks EVERY DAY for all the aspects od my daily live allows me. I had two uncles that served in WWII and Korea and I myself served my Nation. Thank you for what you have and are doing for our Nation. 73's, Rusty.
------------------------------
Message: 4
Date: Wed, 21 Aug 2013 19:57:28 -0400
From: Nick England <navy.radio at gmail.com>
To: vintage-military-radar <Vintage-Military-RADAR at yahoogroups.com>,
Military Surplus Mail List <milsurplus at mailman.qth.net>
Subject: [Milsurplus] manuals free to a good home
Message-ID:
<CAB55hNcG=Gtz_c9eM=ybSCtLE+_CzzLCRoUGczEWhUZVZTmy-w at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Free to a good home -
NAVSHIPS 900,429 May 1945 - Model OBN Transmitter Monitor Scope (for LORAN)
NAVSHIPS 91934 May 1953 - Model VJ-1 and VJ-b Radar Repeater Equipment
IB 82-710-1 May 1948 - Westinghouse Type MU Marine Radar Equipment
Just let me know why you are interested - in the event of multiple
requests the most interesting story wins....priority given to museum
ships
cheers,
Nick
------------------------------
______________________________________________________________
Milsurplus mailing list
Home: http://mailman.qth.net/mailman/listinfo/milsurplus
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Milsurplus at mailman.qth.net
End of Milsurplus Digest, Vol 112, Issue 40
*******************************************
More information about the Milsurplus
mailing list