[Hammarlund] Age list of HQ-129-X?

[Richard Knoppow]

    The SP-400 is a very fine receiver. My first station receiver 
was a surplus BC-779, a version of the SP-200. The 40Mhz version 
used a different arrangement for the RF stages with parallel fed 
plates, series fed in the standard and MF models. I am not sure 
what is in the 400. I think the 400 may not have the Faraday 
screens in the antenna coils.
    One thing all of the series need is a regulator for the LO. A 
VR-150 under the chassis works fine but the plate resistor for 
the LO should be changed from 12K to about 8K. Without the 
regulator the LO tends to pull with the AVC voltage. The late 400 
also had a TC cap in the LO across the tuning capacitor. I don't 
know the value, maybe about 5pF, N-750. Will reduce the warm up 
drift. I let mine run all the time and it was very stable that 
way. Since mine had been modified when I got it I tried all sorts 
of things in the RF, converter, and LO. The original circuit 
works about as well as anything. Mine had the cathode coupled 
triode mod shown in an old CQ magazine. It worked but the 
original circuit works better. The modified circuit may have been 
quieter but it loaded the RF coils so reduced RF selectivity.
    Anyway, its worth putting some work into. I still have this 
receiver.
    I have two SP-600-JX receivers on the back burner. My problem 
is that I can't lift them any more. Hayseed Hamfest makes a 
correct power supply cap for them. If yours have the original 
paper caps they need a complete recaping. You may find a few mica 
caps bad too. Check the 51pF cap in the BFO since it seems to 
develop a jump.
    Do NOT bend the tuning capacitor plates. They should be 
straight. However, the stators and fixed with screw clamps and 
fiber washers and can drift off. They are not difficult to 
re-center. Some people seem to have done plate bending to get 
calibration. Of course they make it impossible and its usually 
impossible to straighten out the plates again. I think they were 
trying to compensate for mis centered stators.

On 3/20/2020 9:04 PM, Don Cunningham wrote:
> I also have two of the HQ-129X in the repair queue.  Both have 
> the white lettering, but are not stored where I can see the 
> serial numbers.  I am currently working on reviving a Super Pro 
> SP-400-X and an SP-600, so the 129's and an HQ-180 will have to 
> wait.
>
> Hayseed filter caps have always worked fine for me, and are the 
> first things I do before even firing the rig up initially.  I 
> am more of a "user" than doing restorations, I just like the 
> old receivers.
> 73,
> Don, WB5HAK (formerly WPE5CTN MANY years ago, HI)
>
> On 3/20/2020 4:17 PM, Ray LaRue wrote:
>> I have acquired a rather nice HQ-129-X in good physical 
>> condition.  I have not yet recapped it but will get to it 
>> shortly.  I am pairing it up with a nice rebuilt Johnson 
>> Ranger for an operating "classic" station, to go along with my 
>> rice boxes.
>>
>> Is there a list of serial numbers online where I could 
>> estimate it's age?   The serial number on this one is #14574, 
>> stamped into the back of the chassis.
>>
>> Your attention is appreciated.
>> Ray, W4BYG
>>
>
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-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL