I am referring to modern, water-wash flux like this from
http://www.gluguru.com/electronics_materials.htm:
*****
Multicore Water Wash Fluxes-IPA Based
Hydro-X/20â High Activity Flux A high activity water washable flux designed
for the soldering of the most difficult electronic assemblies. Unique activator
package enables a wider process window and the soldering of all common
electronic surfaces with ease.Residues are readily and completely removed by
water wash after soldering. Suitable for lead-free wave soldering.
% Solids: 20 % Halides: 1.0 Acid Value: 24
*****
If you're not using this, you are obviously from the dark ages and you probably
voted for Truman while in your 40's.
No one solders with the crap inside solder anymore unless your living in a
cave. It is like the lap dance with the 20-year-old: you'll never go back to
your wife after soldering with this stuff.
Take my word for it people, I do development electronics all day. That is the
great thing about internet forums: learning to do things the easy way from
people who do it for a living.
73,
Steve, K0SF
----- Original Message -----
From: "Robert Bonner" <rbonner@qro.com>
To: "STEVEN & NANCY FRAASCH" <sjfraasch@embarqmail.com>, "John." <johne@tds.net>
Cc: amps@contesting.com
Sent: Tuesday, July 10, 2007 6:58:56 PM (GMT-0600) America/Chicago
Subject: RE: [Amps] Clippertion L 572B tubes
Of course he is referring to silver solder and Rosin flux. Acid flux usually
used in plumbing corrodes electrical components.
BOB DD
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of STEVEN & NANCY FRAASCH
Sent: Tuesday, July 10, 2007 12:38 PM
To: John.
Cc: amps@contesting.com
Subject: Re: [Amps] Clippertion L 572B tubes
Don't go too crazy replacing tubes. More often that not, a tube is still quite
good after years of use. Assuming that the filaments are wired in parallel,
plug one tube into the amp at a time, key the amp and monitor quiescent plate
current. The resting current should be within 20% of the group mean. If you
have an assortment of tubes, I would match them for resting current (again,
checking them one at a time assuming filaments are parallel connected). If you
have an extreme outlier that has low resting current, I would suspect that it
is weak. Use tubes with similar gain together. The RF transistor industry
used to do this by marking BJTs with an ink to indicate Beta grouping.
I would pull a leakage current check on HV caps. You can do that by putting a
10K ohm resistor in series with a single silicon diode (1N400x) and hook up to
110VAC (one cap at a time). The cap should charge, then not take more than a
few microamps thereafter. Measure the voltage drop accross the resistor; it
should be nil. I find that many caps in old amplifiers leak and require
replacement.
Replace any and all heat damaged components such as resistors and caps. Check
that variable cap plates are parallel. Replace noisy fans. Clean old grease
and re-lube.
Check the bandswitch. If there are broken or burnt contacts, replace it. If
the position stays are worn, replace it too. There is nothing more annoying
than a flaky bandswitch. You can buy silver solder and liquid flux from
various vendors on line.
Check to make sure that all solder connections are intact. I find many
corroded and defective joints in amplifiers. Use liquid flux which will help
clean crud and allow using less heat than without flux.
That's about it. You have a simple amplifier so that this should be pretty
easy. Good luck,
73,
Steve, K0SF
----- Original Message -----
From: "John." <johne@tds.net>
To: amps@contesting.com
Sent: Tuesday, July 10, 2007 10:40:53 AM (GMT-0600) America/Chicago
Subject: [Amps] Clippertion L 572B tubes
I am in the process of restoring a Clippertion L amp. Any thing that I
should look at that has been a problem ?
Looking for some good 572B's pulls or something like that. Need 4.
If one could be found then I could start testing the amp.
Thanks de John KÃCQW
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