[ARC5] Why "Noodling" About Sweep Tubes

[Dennis Monticelli]

Jim,

Thanks for the info on the 5894.  I have one of those but have been
reticent to use it fearing that the high gain at VHF might make it tough to
tame at HF.  Did you take any special precautions when you built that
multi-band HF rig?

Dennis AE6C


On Wed, Oct 23, 2013 at 7:55 PM, Jim Wiley <jwiley at gci.net> wrote:

> 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
>>
>
>