On Nov 10, 2006, at 8:43 AM, Robert B. Bonner wrote:
Item responded to with additional comments:
Rosin-flux, solder wick, silver-tin solder, and a soldering iron are very
hard to use?
I've done it - right up there in the hardest thing to do category.
I didn't do the fix one pin at a time, I did them all at once mounted in an
old Johnson socket to get all the pins square and level with minimum heat as
possible. Sort of the mutated reverse of reattaching those 4X150 anodes.
Prepped the tube pins, prepped the big pins, pushed down into socket all the
way. You get out the black beauty or BUNZ-O-MATIC and heat the pin sleeves
up hot enough to melt solder and they'll be cooking for several minutes.
Partially fill pins with solder. Then slip tube down, touch up with solder
around top edge and hold allowing solder to cool.
Buff pins nice round bottom and stick it back in the amp.
Works good - lasts a long time. :-)
Not my favorite thing to do. Never had to do it on my tubes, just Mr
Cook-Off Buddy's.
After my first 3-500 amp when I was 16 I always used sockets and chimneys.
Air system sockets and chimneys result in higher glass temperatures than is the case with the transverse-fan cooling system used in the SB-220 and TL-922.
I always felt it allowed the envelopes of the tubes to evenly cool around
the tubes. The tube pins get coolest direct air.
So why does the Henry 3K-A, which uses air-system sockets and chimneys, have a history of melting solder out of tube pins #1 and #5 ?
I always felt there would be hot and cooler sides with air blowing just on
one side.
The way we feel is not as good as observing what is happening to the object in question. The bottom-line is that the mfg's marking ink gets toasted brown, we know it's pretty hot.
When I was working in the ham store in the 70's tubes coming out
of amps with the side sucked in and plate heaved over were always
non-chimney amps. I just wonder how bad your amp smells when the 3-500's
are melting?
In my glass-blowing experiences, melting glass emited no odor.
Is there anybody here who at one time was that stupid and can
tell me? Inquiring minds wanna know...
Never ran thermodynamic tests on envelope cooling as felt I had a pretty
good handle on why a chimney was better.
Did you ever look at the marking ink?
In my opinion if you're melting lettering off the tubes you need more air.
Marking ink does not melt, it chars.
I hate blower noise as much as the next guy. That's why I usually put a
small variac with stops on blowers. The low setting is the rag chew mode
and the top setting is the CONTEST (or EME Mode) and whatever in between
depending on my noise tolerance at that time. All my amps sit back along
the wall away from the main op position. Right now all the VHF and UHF
boxes are all factory HANK 3000 series noisier than crap. I sold my 4K-U oh
that was a sweetheart... and started development of all new HF amps here.
Shack all blown up, no walking space, wife all pissy, big scratch on her leg
from walking into shack hitting loose panels (that will teach her) My
comment don't get blood on those didn't go over well. There's nothing like
stubbing your toe on 100# plus transformers.
I do have to get this stuff done. Spending too much time on computer, but I
am having fun with you guys thanks...
Drawing scientific conclusions based on your feelings rather than on observations and measurements is not unlike walking on thin ice and rolling dice.
We might not always agree, but it is fun to play with guys who like to build
stuff.
BOB DD
...
cheers, Bob
R L Measures, AG6K, 805.386.3734
r@..., rlm@..., www.somis.org
