[HBR] Some Compactron modules

[Phil]

Sounds like fun, by the way, what is a "Pullen Mixer"?  It seems I've 
heard the term, but can't place it.  Guess I could Google it.

My "Summer Homebrew Project" is a regen receiver, primarily for LF 
(200-530KCs) but will also tune the BCB & SW.  5 Tubes (2 of them are 
double triodes) + a silly-cone bridge rectifier, it has a few whips and 
bells.  Things  like selective audio filtering centered on 400, 600 & 
1020 CPS, accomplished via LC filters. Only SS devices in it are the 
rectifiers (didn't feel like generating more heat than necessary with a 
5Y3 or similar).

73 de Phil,  KO6BB
http://www.qsl.net/ko6bb/  (Web Page)

PRESENT RADIOS:
Grundigs:    S-350 (~2006), G6 (2011) & S450DLX (2014).
Icom:        R-75 With Cascaded 250 & 125Hz CW Filters. (~2005)
Icom:        IC-7200 Transceiver (~2015).
Radio Shack: DX-380 digital portable (~1990).
Zenith:      Royal-7000 Transoceanic Portable (~1968).

ACCESSORIES:  Homebrew LF-MF Pre-Amp, MFJ-993B HF Auto-Tuner.
               Homebrew 8 Hz Audio Filter.

ANTENNAS:  88 foot Long Ladder-line fed dipole at 35 feet AGL.
            Active Mini-Whip at 36 Feet AGL for LF/MW.
            37 foot "Low Noise Vertical" at 11 feet AGL for LF/MW/SW.

Merced, Central California, 37, 18, 37N   120, 30, 6W CM97rh

On 7/10/2015 10:13 PM, Ian Wilson wrote:
> I couldn't resist tinkering. The RF module uses the 6BH11
> (dual triode, pentode) as a 16MHz premixer VFO (this makes
> sense, since you wouldn't want to use the pentode part of the
> tube anywhere in the signal path). The LO part of the VFO is
> one of my better efforts in terms of stability (by eyeball).
>
> Two triodes of the 6AC10 are used in a Pullen mixer (the
> plan was to have no RF gain ahead of this). The 9MHz output
> is coupled through a tuned transformer to the xtal filter.
>
> The schematic for the filter has 3 sections but I measure two
> bumps. Also the bandwidth is about 3.4kHz while the schematic
> claims 2.5kHz. So it looks as if I bypassed a section, or something.
>
> I guess all this is telling me that I should rebuild the 9MHz IF
> horror-amplifier instead of dumping it :)
>
> 73, ian K3IMW
>
>
> On Wed, Jul 8, 2015 at 6:53 PM, Ian Wilson <ianmwilson73 at gmail.com> wrote:
>
>> A few years back, I got part way through a receiver based
>> on the 'KCS Compactron' (in two of the last issues of GE
>> Ham News). Naturally I made some radical changes. My
>> version used a 9MHz IF (instead of 455kHz), Pullen mixers,
>> different tube lineup, etc. This had some promise but attempting
>> to use the 6AR11 (twin high-gm semiremote pentode, TV IF amp)
>> with inadequate shielding at 9MHz led to .. predictable results.
>>
>> Anyway. I don't seem to do anything with this except kick it
>> around the floor. It was built on a number of single-sided PCB
>> "modules" using ugly, er, ground-plane construction. There are
>> three 5.5"x4.5" modules and one 9.5"x6" module. There is a
>> nice premixer 16MHz VFO (high-quality air variable and ceramic former
>> variable inductor, mixed with an 11MHz xtal osc). The modules are:
>>
>> RF: 6BH11 (dual triode + pentode); 6AC10 (triple triode);
>>         VFO components and 9MHz homebrew filter
>>
>> IF: 6AR11 (dual semiremote pentode)
>>
>> BFO (9MHz)/Product detector: 6U10 (triple triode)
>>
>> Audio/AGC: 6T10 (beam power pentode + shpar cutoff pentode);
>>             6U10 triple triode; small (8W) audio output transformer
>>
>> The Compactrons were all NIB and have a few hours of
>> operation on them. The sockets are all high quality ceramic
>> 12-pin Compactron.
>>
>> I actually have schematics for all the modules (they may have
>> had work done on them but should save lots of detective work).
>>
>> I would like $15 for the set of modules plus shipping from
>> 92620. Happy to trade for something as long as it's smaller
>> and glowbug-oriented :)
>>
>> Please reply off-list. First come first served.
>>
>> 73, ian K3IMW
>>
>>