[R-390] PRC-77 batteries
mikea
[email protected]
Wed, 16 Jan 2002 11:28:26 -0600
Sandy,
Here's what I got from you; the HTML shows up as unformatted HTML
in all its glory: left and right angle-brackets, etc., which is
almost impossible to read. _And_ it shows up as a "Content-Type:
text/html" attachment. The letter itself has no body at all. This
is something I tend to skip as not worth the trouble.
If you can somehow coax hotmail into sending Email as plain text,
your letters will have a _lot_ better chance of getting read by
us old pharts with text-only mail readers.
And if you'll trim your letters to remove extraneous matter --
the stuff about sand-state replacements for our boatanchor
glowbottles -- that'll drop the line usage and mailspool size
a little bit, too, which will be A Good Thing.
THanks.
> From [email protected] Wed Jan 16 11:00:44 2002
> Return-Path: <[email protected]>
> Received: from mailman.qth.net (mailman.qth.net [63.238.179.60])
> by mikea.ath.cx (8.11.6/8.11.1) with ESMTP id g0GH0YP72738
> for <[email protected]>; Wed, 16 Jan 2002 11:00:36 -0600 (CST)
> (envelope-from [email protected])
> Received: from mailman.qth.net (repentium.qsl.net [127.0.0.1])
> by mailman.qth.net (Postfix) with ESMTP
> id D5816328670; Wed, 16 Jan 2002 11:59:02 -0500 (EST)
> Delivered-To: [email protected]
> Received: from hotmail.com (f257.law7.hotmail.com [216.33.236.135])
> by mailman.qth.net (Postfix) with ESMTP id 23E4B328576
> for <[email protected]>; Wed, 16 Jan 2002 11:58:46 -0500 (EST)
> Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC;
> Wed, 16 Jan 2002 08:58:17 -0800
> Received: from 65.114.22.66 by lw7fd.law7.hotmail.msn.com with HTTP;
> Wed, 16 Jan 2002 16:58:17 GMT
> X-Originating-IP: [65.114.22.66]
> From: "Sandy Geiger" <[email protected]>
> To: [email protected]
> Mime-Version: 1.0
> Content-Type: text/html
> Message-ID: <[email protected]>
> X-OriginalArrivalTime: 16 Jan 2002 16:58:17.0938 (UTC) FILETIME=[FECC3B20:01C19EAE]
> Subject: [R-390] PRC-77 batteries
> Sender: [email protected]
> Errors-To: [email protected]
> X-BeenThere: [email protected]
> X-Mailman-Version: 2.0.8
> Precedence: bulk
> List-Help: <mailto:[email protected]?subject=help>
> List-Post: <mailto:[email protected]>
> List-Subscribe: <http://mailman.qth.net/mailman/listinfo/r-390>,
> <mailto:[email protected]?subject=subscribe>
> List-Id: Collins Radio R-390A Military HF Receiver <r-390.mailman.qth.net>
> List-Unsubscribe: <http://mailman.qth.net/mailman/listinfo/r-390>,
> <mailto:[email protected]?subject=unsubscribe>
> List-Archive: <http://mailman.qth.net/pipermail/r-390/>
> Date: Wed, 16 Jan 2002 11:58:17 -0500
> Status: RO
> Content-Length: 5623
> Lines: 96
>
> <html><div style='background-color:'>
> <DIV>
> <P>Hello-I picked up a couple of functioning PRC-77s at a gun show Sunday. The batteries are weak;anybody know where I can get replacements ? TIA,Sandy G.<BR><BR> </P></DIV>
> <DIV></DIV>C.H.(Sandy)Geiger III
> <DIV></DIV>
> <DIV></DIV>
> <DIV></DIV>
> <DIV></DIV>>From: "AI2Q Alex"<[email protected]>
> <DIV></DIV>>Reply-To:<[email protected]>
> <DIV></DIV>>To: "'Steve Goode'"<[email protected]> ,<[email protected]> , "'Roger L Ruszkowski'"<[email protected]>
> <DIV></DIV>>Subject: RE: [R-390] 6DC6 Replacement
> <DIV></DIV>>Date: Wed, 16 Jan 2002 11:38:37 -0500
> <DIV></DIV>>
> <DIV></DIV>>
> <DIV></DIV>>Hi Steve:
> <DIV></DIV>>
> <DIV></DIV>>I confess! I've poked JFETs into both 26C6 mixers on my R-392, and those
> <DIV></DIV>>24-V stages work really well. I used a Dremel tool cutter to scribe the
> <DIV></DIV>>glass of 7-pin miniature tubes, cracking them open and removing the innards.
> <DIV></DIV>>I then soldered the JFETs with drain source and gate connected to the old
> <DIV></DIV>>plate, cathode, and grid leads, respectively. After inserting a label with
> <DIV></DIV>>my callsign on it, I then glued the glass envelopes closed. I popped 'em
> <DIV></DIV>>into the R-392, where these solid-state jobbies perform flawlessly. I can
> <DIV></DIV>>elaborate about the glass cutting procedure if you're interested.
> <DIV></DIV>>
> <DIV></DIV>>As per the 1977 QST article, last night I fired up an 1800-volt bipolar
> <DIV></DIV>>junction transistor in the relay circuit of an old Drake TR4. The device is
> <DIV></DIV>>a TV horizontal output transistor.
> <DIV></DIV>>
> <DIV></DIV>>I pulled the relay driver tube and put my little solid-state jobbie (fabbed
> <DIV></DIV>>on a scrap of circuit board) in there with some clip leads, with my VTVM
> <DIV></DIV>>hanging in to see what's happening with the switching levels. I also put a
> <DIV></DIV>>reverse-biased diode across the driven relay in order to quash any possible
> <DIV></DIV>>counter-EMF that might do in the transistor. The xstr that drives the relay
> <DIV></DIV>>is in turn driven by a cheap N-channel JFET such as an MPF-102 or MPF-105,
> <DIV></DIV>>which derives its Vdd from a diode and a 300 uF cap hanging off the filament
> <DIV></DIV>>line as a simple halfwave rectifier/filter. The FET gate is extremely
> <DIV></DIV>>high-Z, and sees the control voltage at a VOX/anti-VOX summing point. Works
> <DIV></DIV>>like a champ and offloads the filament line.
> <DIV></DIV>>
> <DIV></DIV>>Now on to RF "replacements." Finding suitable high-voltage FETs for the
> <DIV></DIV>>cascode circuits may be a problem. The Idss of the output FETs in these
> <DIV></DIV>>pairs has to complement the input FET. As for dual-gate MOSFETs, I know that
> <DIV></DIV>>Dan's Small Parts has some.
> <DIV></DIV>>
> <DIV></DIV>>Your thoughts?
> <DIV></DIV>>
> <DIV></DIV>>Vy 73, AI2Q, Alex in Kennebunk, Maine .-.-.
> <DIV></DIV>>
> <DIV></DIV>>
> <DIV></DIV>>
> <DIV></DIV>>
> <DIV></DIV>>-----Original Message-----
> <DIV></DIV>>From: [email protected] [mailto:[email protected]]On
> <DIV></DIV>>Behalf Of Steve Goode
> <DIV></DIV>>Sent: Wednesday, January 16, 2002 10:41 AM
> <DIV></DIV>>To: [email protected]; Roger L Ruszkowski
> <DIV></DIV>>Subject: Re: [R-390] 6DC6 Replacement
> <DIV></DIV>>
> <DIV></DIV>>
> <DIV></DIV>>Alright! I must confess that I have had similar evil thoughts.
> <DIV></DIV>>
> <DIV></DIV>>WARNING---SAND STATE THOUGHTS TO FOLLOW!!!!
> <DIV></DIV>>
> <DIV></DIV>>I love the way my R-390A performs. Right now the only sand in it is the
> <DIV></DIV>>Navy approved power supply changes. It even has a working ballast tube.
> <DIV></DIV>>But I want this receiver to work forever! So what happens when I run out of
> <DIV></DIV>>tubes? My thoughts are that anything behind the mechanical filters is fair
> <DIV></DIV>>game since that should have minimal performance hits in dynamic range,
> <DIV></DIV>>sensitivity, etc. So I was thinking of looking at the IF, detector, agc,
> <DIV></DIV>>calibrator circuits to start experimenting on. What I have found so far in
> <DIV></DIV>>discussions with others who have actually done solid state conversions is an
> <DIV></DIV>>article from the April 1977 QST (it is not the April fool article). This
> <DIV></DIV>>article shows how to make plug in solid state replacements for any tube
> <DIV></DIV>>using JET or MOSFETs in cascode with high voltage transistors. This is as
> <DIV></DIV>>far as I have gotten. Anyone else willing to confess? Anyone actually
> <DIV></DIV>>succeeding in doing a solid state conversion?
> <DIV></DIV>>
> <DIV></DIV>>Steve, K9NG
> <DIV></DIV>>
> <DIV></DIV>>
> <DIV></DIV>>
> <DIV></DIV>>_______________________________________________
> <DIV></DIV>>R-390 mailing list
> <DIV></DIV>>[email protected]
> <DIV></DIV>>http://mailman.qth.net/mailman/listinfo/r-390
> <DIV></DIV>>
> <DIV></DIV>>_______________________________________________
> <DIV></DIV>>R-390 mailing list
> <DIV></DIV>>[email protected]
> <DIV></DIV>>http://mailman.qth.net/mailman/listinfo/r-390
> <DIV></DIV></div><br clear=all><hr>Send and receive Hotmail on your mobile device: <a href='http://go.msn.com/bql/hmtag2_etl_EN.asp'>Click Here</a><br></html>
> _______________________________________________
> R-390 mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/r-390
--
Mike Andrews
[email protected]
Tired old sysadmin since 1964