[AMRadio] Seeking tubes

Todd, KA1KAQ ka1kaq at gmail.com
Fri Jul 8 11:01:31 EDT 2005

On 7/8/05, Donald Chester <k4kyv at hotmail.com> wrote:
> The 849 is similar, but bigger than the 204A.  It's the predecessor to the
> 833A.  The RCA book says the 849, 204-A and 851 should all be mounted upside
> down so that the filament is up and the plate down.

Right on the money, Don. The lettering indicates this also, the pins
need to be facing up to read it. But the used one in the original
crate is oriented like a 'regular' tube with the holder for the pins
at the bottom.

I have a helluva time remembering all of the older (pre-1940 type)
tubes it seems. But a search of completed items also showed one 849
that sold for $125 used. Filament was checked and good.

Okay, so does the 851 look like a 204 but about twice as large? I have
a huge old tube boxed up with a large center section and long neck on
either end. I think that the piece around the cap is some kind of
plastic, too. Unfortunately I don't have a place to display the old
tubes right now, so most are boxed up.
> I have run into a couple of hams on the air running 204A's.

I've seen old articles that show them in breadboard rigs, mounted
horizontally. They do have that classic look about them. All of those
exposed connections...it's amazing that anyone survived by today's

> Those older tubes were always expensive.  Back in the mid 30's, a 204A sold
> for about $85 - the equivalent to hundreds of dollars in today's money.  The
> newer 833(A) sold for a fraction of that.  That's why BC stations were
> interested in retrofitting their transmitters.

I have a few 833s also, but nothing that uses them. Need to trade them
off for some 810s, but someone told me to trade 1-for-2 since the 833
is the equivalent of 2 810s. No idea what 833s are going for these
> In the mid 70's I ran into about a dozen Amperex 849A's piled in a cubby at
> Young Engineering in Salem MA.  I couldn't get the guy to reduce his price;
> he wanted about $20 each for them, as is.  No way to test them, but they
> looked good.  I turned him down, and later, they apparently all got broken
> as they shuffled stuff around in the old warehouse.
> I still kick myself for not taking a chance on those tubes.

I bet we all have at least one story like that. Knowing how things
were when I first got interested in radio about the same time, $20 for
old, used tubes of unknown quality multiplied by 12 would have seemed
like a lot to me. Of course, we tend to think differently today with
another 30 years of knowledge and shrinking supplies under our belts.

Both of my 849s are Amperex examples, that much I do remember. Since
the tubes aren't used much anymore and all that, there must be a huge
cache of the mounting 'clips' laying around out there? I have one or
two that resemble the part of a knife switch that the blades slide
into when closed, but no side pieces for the pins. The tops just look
like a fuse clip on a ceramic standoff.

~ Todd,  KA1KAQ

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