[ARC5] Why "Noodling" About Sweep Tubes

[Geoff]

While the 829A was used for a very short time the 829B was the best known 
during WW2....and a lot more reliable. Both versions and the 3E29 had 6.3 
and 12.6 rated filaments. The 829B and 3E29 has an internal screen to 
cathode bypass cap which made it unusable for some applications.

The AX9903 was an attempt to improve the 829B but was a fatal mistake for 
Amperex as the plate seals were extremely weak and easily broken. Im not 
aware of a AX-9903A and the 9903 was the only one in the Amperex catalogs 
and for only one year. I have one NIB in the collection.

Amperex quickly released the 5894 as the replacement and the Europeans 
called it the CV2797, QQE06-40, and RS1009, plus a few others as each 
company had their own numbering system.

Im unsure what 5894A and B signify, possibly special testing for Motorola or 
other large OEM user.

The 7854 is a ruggedized and higher power version and Moto had their own 
8643 designation for which they overcharged their customers. I used a 7854 
in a Johnson Viking I when the 4D32 was almost unobtainium and it wanted to 
run more power than the PS and modulator transformer could safely deliver. 
When the USAF released huge quantities of 4D32's in the late 90's I stocked 
up for the Johnson and a Collins 32V2.

Carl


----- Original Message ----- 
From: "Jim Wiley" <jwiley at gci.net>
To: "Ken Gordon" <kgordon2006 at frontier.com>; "Dennis Monticelli" 
<dennis.monticelli at gmail.com>
Cc: <Arc5 at mailman.qth.net>
Sent: Wednesday, October 23, 2013 10:55 PM
Subject: Re: [ARC5] Why "Noodling" About Sweep Tubes


> The much better version of the venerable 829A, that fits the same socket 
> and runs from the same voltages, is the 5894A (also known as the QQV06-40A 
> and AX9003A).
>
> Also inexpensive, because not many people know what they are, particularly 
> when labeled using the European numbering system. Puts out more power than 
> the 829B, mostly because it was designed from the ground up as a VHF dual 
> power tetrode,  so it is a bit more efficient.
>
>  I built a HF rig using one and got around 150 watts output, 160 thru 10 
> meters.  Used another in a Johnson-Viking 6N2 and got an easy 110 watts 
> AM, 140 watts CW output. The 5894A works at full power up thru 180 MHz and 
> at reduced ratings thru 450 MHz.
>
>
> - Jim, KL7CC
>
>
> On 10/23/2013 6:21 PM, Kenneth G. Gordon wrote:
>> On 23 Oct 2013 at 18:36, Dennis Monticelli wrote:
>>> I just remembered another tube. The 829B was very expensive in the WW2 
>>> era but it's practically free at the hamfests now. You find them mil 
>>> grade NIB. I don't think I paid more than $2 for mine. You can parallel 
>>> the two tetrode sections or use them push-pull. I think they're good for 
>>> 40W plate per section. 12V heaters and a 7 pin socket (Septar?) that is 
>>> worth more than the tube.
>> The 829B is one of my favorite tubes. The pulse version is the 3E29. I 
>> buy them as often as I see them for under $5 each. They will output 
>> something like 100 watts at 2 meters. They are, essentially, a pair of 
>> 807s in one envelope with far shorter interconnecting leads, and reduced 
>> plate dissipation rating since you can't really have 70 watts PD in that 
>> small an envelope. They make a magnificent push-pull oscillator in 
>> addition to being an excellent push-pull amp. Ken W7EKB
>
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