[Milsurplus] most Dangerous Transmitters

Wed Nov 20 09:23:36 EST 2019

Hi Mike -

I'm curious - you say "bottom" - do you still have the shock mount base
('outriggers' that Ray refers to) on your transmitter? There are holes in
it that allow stem casters to be mounted. If so, you'd not likely ever have
a tip-over problem. If not, I'd consider you to be very lucky.

My D model was given to me as a wedding gift by W1DEC. He picked it up from
a ham in RI who added casters directly to the cabinet corners in place of
the shock mount. I'd also had the top drawer out numerous times with no
issue. Then a year or so back I was working on the exciter section with my
good friend John/W3JN. Everything was fine until I inadvertently leaned
ever so slightly on the top edge of the front panel.

Over it came! Fortunately we were able to catch it in mid air and push it
back. Not so sure I'd have been able to do so alone. Probably wouldn't have
gotten me, but most certainly would've done some serious damage to the
transmitter.

I'd been looking for a shock mount base for years and was given one shortly
thereafter by Ross/W1EKG. Located some heavy duty stem casters earlier this
year and installed them just before the move, now I need to get it
installed on the cabinet.

The interlocks are an issue in that they oxidize and can create
intermittent problems or complete loss of HV. Simple, regular cleaning is
all that is required. I've never been a fan of bypassing them permanently
and I try to replace any that are missing. True, sometimes you need to
employ a temporary bypass for testing purposes, but *temporary* means just
that. They were put there for a reason - to protect you - long before the
politically-correct, litigious society we now have existed. Very basic,
common sense when common sense was indeed common.

~ Todd,  KA1KAQ/4

On Tue, Nov 19, 2019 at 9:24 AM Mike Feher <n4fs at eozinc.com> wrote:

> Hi Ray –
>
>
>
> I do not recall the exact size of the wheels, but I believe that they are
> close to 4 inches in diameter. The plate current meter indeed has HV on it.
> Regardless, in the 40 or more years that I have had it, I never had an
> issue with stability at all, even though I have had the drawers out many
> times. 73 – Mike
>
>
>
> Mike B. Feher, N4FS
>
> 89 Arnold Blvd.
>
> Howell NJ 07731
>
> 848-245-9115
>
>
>
> *From:* Ray Fantini <RAFANTINI at salisbury.edu>
> *Sent:* Tuesday, November 19, 2019 9:04 AM
> *To:* Mike Feher <n4fs at eozinc.com>; MMRCG at groups.io; 'milsurplus at mailman'
> <milsurplus at mailman.qth.net>
> *Subject:* RE: [Milsurplus] most Dangerous Transmitters
>
>
>
> How big were the wheels you put under it? With small heavy duty wheels it
> may be stable but I have seen people install furniture casters that have
> swivel bases and that makes the smallest push on the top drawer down with
> it extended tipsy! The outriggers are the only way to guarantee stability,
> that along with bolting the transmitter down. But that’s just me, your
> results may vary.
>
> Dose the TRW have the isolated plate current meter?
>
>
>
> Ray F/KA3EKH
>
>
>
>
>
> *From:* Mike Feher <n4fs at eozinc.com>
> *Sent:* Monday, November 18, 2019 7:37 PM
> *To:* Ray Fantini <RAFANTINI at salisbury.edu>; MMRCG at groups.io;
> 'milsurplus at mailman' <milsurplus at mailman.qth.net>
> *Subject:* RE: [Milsurplus] most Dangerous Transmitters
>
>
>
> Hi Ray –
>
>
>
> Interesting that you would say that. I have had a 368 for over 40 years
> without ever an issue of the sort you described. Indeed I did place wheels
> on the bottom, yet II never had an issue with it attempting to tilt over. I
> also repainted the whole unit and replaced all the internal wiring without
> issues. I feel pretty good about my TRW T-368F and it has performed
> admirably for me. 73 – Mike
>
>
>
> Mike B. Feher, N4FS
>
> 89 Arnold Blvd.
>
> Howell NJ 07731
>
> 848-245-9115
>
>
>
> *From:* milsurplus-bounces at mailman.qth.net <
> milsurplus-bounces at mailman.qth.net> *On Behalf Of *Ray Fantini
> *Sent:* Monday, November 18, 2019 1:33 PM
> *To:* MMRCG at groups.io; milsurplus at mailman <milsurplus at mailman.qth.net>
> *Subject:* [Milsurplus] most Dangerous Transmitters
>
>
>
> My vote would be the T-368 transmitter. The first thing most Hams do is
> bypass all the interlocks. The stupid thing about that is in order for the
> HV distribution to work the drawers have to be all the way that sets the
> interlocks. Have had people tell me the interlocks become internment, so
> why not just fix them.
>
> I cannot think of any reason why you need to operate it outside the case,
> for it to work removed from the case you would also have to build up HV
> jumpers. The overload adjustments are all located on the front of the power
> supply, any diagnostics of the power supply can be done at low level or by
> isolation along with pushing the drawers back in but imagine most people
> don’t want to do the additional work sliding the drawers in and out when
> trying to diagnose an overload issue.
>
> Second thing would be the Hot PA tank, the plate current meter and the
> band selector switch for the output tank are all at HV potential. Later
> series have an isolated PA current meter but the first generation had only
> a small amount of isolation and doing things while the transmitter is on
> like washing off the front of the transmitter including the plate meter
> with a wet rag have interesting results. The tube that is used as a shunt
> across the screen of the PA tube as part of the keying system can be fun
> also and although I am not certain of this would suspect that when the
> transmitter is in HV on standby and the shunt is full on it may produce
> X-Rays. Fortunately there are tons of shielding when the drawer is in place.
>
> And last but not least my favorite thing about the 368, unless the
> transmitter is secured to a wall or the floor it needs to be on a special
> dolly that has outriggers attached. Most Hams remove this first thing
> because they keep stubbing their toes on the outriggers. What’s worse and I
> have seen this twice is that they will install wheels or casters under the
> four corners of the transmitter and when you do this if you pull out the
> top drawer to far or fast the transmitter will tip over and do its best to
> kill you!
>
> The manual states that never attempt to pull out more than one drawer at a
> time. If it starts to fall forward you will not be able to catch it.
>
> The T-368 is a great transmitter when used by the book, unfortunately most
> out there have been Ham Hacked in a great number of ways. There are volumes
> written about how to hack up the modulator. Maybe the only thing that’s
> been Ham Hacked more would be the ARC-5 radios and the BC-348
>
> Well that’s my rant, what’s yours?
>
> Ray F/KA3EKH
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