[Collins] 4D32 question

[jeremy-ca]

The 4D32 is the same as the 4D22 except for heater voltage.
Yes, the 829B is rated at 40W and the Johnson manual derates the input 
accordingly. The 5W difference in the claimed output in the Viking I wont 
make a break a QSO.
 Or just put a small fan on it as Hallicrafters does with the HA series of 
VHF transverters. I still use a HA-2 and HA-6 with some SS mods to the 
receive path. Hears better than a DEM xvtr and with a very low phase noise 
TS-830 as the IF it has proven the best Ive ever used on those bands. It 
even shelved my all Collins R390A.

As Glenn already stated the 5894 and its big brother 7854 work just fine 
with sections in parallel. Motorola had their own version of the 7854 and 
5894 primarily to deceive the service tech into buying the more expensive 
versions. A NOS 5894 typically goes for $5-10 tops at hamfests. Old 2 way 
shops are throwing away their tubes, Ive picked up free boxes of all types 
from a few local shops who are struggling to survive against Nextel and cell 
phones.

I cant even give away the two UHF GE Master Pros's I have out in the 
repeater trailer. Off to the dump they go very soon. One is even set up on 
440.

Carl
KM1H





----- Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
To: "jeremy-ca" <km1h at jeremy.mv.com>
Cc: <collins at mailman.qth.net>
Sent: Monday, August 06, 2007 6:02 PM
Subject: Re: [Collins] 4D32 question


> On Mon, 2007-08-06 at 17:22 -0400, jeremy-ca wrote:
>> Johnson included instructions on converting to the 829B. I'd guess that 
>> it
>> was applicable to the 32V series also.
>>
>> The 829B, 3E29, 5894 and 7854 are still fairly common so if 4D32's run 
>> out
>> again we always have a backup plan.
>>
>> Carl
>> KM1H
>>
> I don't know that I've ever seen a 4D32. Does it have two tubes parallel
> inside or just one? I see a 4D22 with the same specifications in my old
> handbook but with a center tapped heater for 12 and 24 volts.
>
> Anyway the 4D tubes have a rating of 50 watts plate dissipation while
> the 829B has a 40 watt rating. I have boucoup 829B and plenty juniors as
> 832. And the bases aren't wildly different, though paralleling the tubes
> in the 829 may need a little care of individual grid and plate parasitic
> suppressors to keep them from oscillating.
>
> Paralleling pieces of 5894 may not work well because it has internal
> neutralization capacitors set up for push-pull operation and those would
> add to the grid-plate capacitance when paralleled.
> -- 
> 73, Jerry, K0CQ, Technical Advisor to the CRA
> All content copyright Dr. Gerald N. Johnson, electrical engineer
>
>