Hello Steve,
Glad to see you are moving forward on your conversion project ;-) I don't know
how many such RF decks have found their way into the hands of deserving 6m
operators, but I suspect there are still many of these things sitting around in
barns and garages around the world.
Like you, I put off the conversion of mine for a number of years. In my case,
I
obsessed about mating it with a power supply and didn't get around to putting
it
on the air until I was able to find a power supply. However, when I actually
got
around to starting in on the RF deck, I was amazed at how fast and easy it was!
I
mention this because I am afraid you might be overcomplicating the process.
There
is NO machining necessary, and it is easily done using a screwdriver, a hand
drill, and a saw. All the unusual parts are readily available from the local
hardware store and it is quite straightforward to assemble them to create a
very
stout 6m amp that will easily handle the high duty cycle required by JT65A
mode.
HDPE cutting boards provide a source of material for the ends of the adjustable
coil, which are mounted to the bottom of the chassis by pieces of angle
aluminum
screwed to the bottoms. The adjustable shaft is simply a threaded brass rod
and
the guide for the tuning slug is simply some brass hobby tubing put over some
brass threaded rod or solid brass rod (found in the same bin as the brass hobby
tubing). If anybody lives further out in the boonies than I do (which is
doubtful), such parts are easily obtained on-line here:
http://www.smallparts.com/
It also helps tremendously to have an MFJ Antenna Analyzer. You also may find
it
necessary to purchase a few 857 style doorknob capacitors to use as blocking
capacitors and to create the total capacitance required for loading. Other
than
that, the most difficult thing for me to come up with was the right angle drive
to
match up at the correct height as the existing tuning dial. I found a pair of
surplus right angle drives and was able to couple them together to create a
mechanical arrangement that could drive the tuning slug at the right height and
still couple with the standard tuning dial on the front panel. Of course,
there
are many ways you can do this, and one of the nice things about building your
own
is that you can mount the coil and the slug at whatever height is convenient
for
you, to match whatever right angle drive you come up with ;-) You might even
want
to try a flexible shaft and avoid the entire right angle drive problem entirely!
Anyway, the bottom line is that if you basically duplicate the photos shown on
the
web page, you can easily fabricate the parts with hand tools, and will end up
with
something that tunes easily and is quite broad band. Given the variability in
the
way the original Henry amps were constructed, I fail to see where there would
be
any advantage in anybody trying to fabricate parts that would hope to fit all
situations anyway.
GL and VY 73, Lance
On 12/20/2010 3:52 PM, K1SG@aol.com wrote:
> A number of folks on this reflector are in progress of converting the Henry
> 2000D/3000D commercial amplifiers to 6 meters. There is a wonderful show and
> tell
> on this subject on W7GJ's website
> http://www.bigskyspaces.com/w7gj/6mHenry3CX3000A7.htm and I suspect many have
> already started the project. I've been making slow progress on mine, but
> expect to
> get it finished in the fullness of time.
> My current hang up has been with obtaining and machining the parts needed for
> the
> output tuning coil, particularly the slug tuning arrangement.
> I've found a friend willing to do the hard parts (the machining itself) for
> me.
> Would there be enough interest to do a group buy on the copper, brass and PVC
> pieces for this? It makes sense to do more than one if we're going to do it
> at all.
> If you have a 3000D sitting on your bench waiting for conversion to 6 meters,
> wondering about the construction of the tunable output coil, and would be
> interested in sourcing the machined parts for it, please contact me off-list.
> Thanks very much (and a tip of the hat to Lance!)
> 73,
> Steve
> Steve Gilbert
> K1SG
> K1SG@AOL.com <mailto:K1SG@AOL.com>
--
Lance Collister, W7GJ (ex: WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8, E51SIX, 3D2LR)
P.O. Box 73
Frenchtown, MT 59834 USA
QTH: DN27UB
TEL: (406) 626-5728 URL: http://www.bigskyspaces.com/w7gj
LIVE MESSENGER CHAT: w7gj@hotmail.com SKYPE: lancew7gj
2m DXCC #11, 6m DXCC #815
Interested in 6m EME? Ask me about subscribing to the Magic Band EME email
Google
Group!
(or click on the link at the bottom of my web page above)
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