|[AMRadio] Mfg date for 4-400 series|
barrie at centric.net
Fri Mar 23 12:41:08 EST 2007
I have an HB-3 here that shows a data sheet for the 4-400A dated 9-62.
I also have an Eimac catalog from the early 1950s that shows the 4-400.
73, Barrie, W7ALW
----- Original Message -----
From: "John Lawson" <jpl15 at panix.com>
To: "Discussion of AM Radio in the Amateur Service"
<amradio at mailman.qth.net>
Sent: Friday, March 23, 2007 9:32 AM
Subject: Re: [AMRadio] Mfg date for 4-400 series
> On Fri, 23 Mar 2007, Bob wrote:
> > According to the info that I have, they were in production in 1950.
> > were not listed in the 1948 data sheets. So it could be between 1948
> > 1950.
> > Hope this helps.
> Actually, this deepens the Mystery - both my HB3s reach from the late
> 30s to the early 60s... they were updated by subscription, so it depended
> on who had them as to exactly which updates got posted.
> I have a 1962 TT5 that goes directly from 4-250A to 4-1000, as do the
> HB-3 sets.
> I am lacking RCA transmitting tube data from 1963 - 1971.
> The 4-400 does appear in the 1972 TT5 manual.
> So: if they were made starting in 1950 - why are they not in the data
> books until nearly 15 years later..?
> I'm sure there's a fine answer out there, somewhere.... just one of
> those trivial pusuits to distract one from the day's Business.. ;}
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