[GreenKeys] ST-8000A and ST-6000 (was "More where these came from")

[Bill Henry]

Thanks for the kind words, guys.
Here's a short time-line of RTTY modems by Irv Hoff, HAL, and Dovetron.

Nov, 1964 RTTY Journal, Irv Hoof, K8DKC and Keith Peterson W8SDZ - 
"Mainline TT/L FSK Demodulator" (TT/L-1)

Sept, 1967, HAL Devices RT-1 RTTY Demodulator.
         I designed the RT-1 for USAF MARS duty and it worked - but 
"I've had better ideas".

Sept, 1967 RTTY Journal & May + June 1969 QST, Keith Peterson, W8SDZ, 
and Irv Hoff, K8DKC - TT/L-2 FSK Demodulator.

Sept, 1968 RTTY Journal & April, 1970 QST, Irv Hoff, W6FFC - 
"Mainline ST-3 Solid State FSK Demodulator".
         It was about this time that Irv and HAL started 
communicating.  We discussed offering the ST-3 but Irv wanted to wait 
until he finished the ST-6.

May, 1970 RTTY Journal & Sept, 1970 Ham Radio, Irv Hoff, W6FFC - ST-5 
RTTY Demodulator

Sept, Oct, Dec, 1970 RTTY Journal & Jan. 1971 Ham Radio, Irv Hoff, 
W6FFC - ST-6 RTTY Demodulator.
         HAL started supplying circuit boards for the ST-6 in 
September, 1970 and complete wired units by April, 1971.

Sept, 1972, HAL ST-6000 RTTY Demodulator.
         The ST-6000 started out to be an ST-6 that didn't need 
toroids but grew into something that was quite different.

Sept, 1973 (?), Hank Scharfe, W6SKC - Dovetron MPC-1000.  I believe 
he first showed it at the 1974 Dayton Hamvention.

April, 1977, HAL ST-5000, a lower-cost and reduced feature version of 
the ST-6000.

April, 1984, ST-8000 HF Modem.
         This included all the bells and whistles I always wanted an 
a modem - and used some 1500 components (aka "labor intensive").

Sept, 1990, HAL bid the ST-8000A in response to a USAF supply 
contract.  The specifications were based on the Frederick 1280A/M 
Militarized Modem.
         In all, we shipped about 700 to the USAF by 1993.  It now 
appears that many remained in their depot packing at McClellan AFB
         until it was closed.  I've been told that some were then 
warehoused at Tinker AFB.

After that, HAL switched to DSP technology - PCI-4000, DSP-4100/2K, 
P-38, DXP-38, etc.  These modems use about 1/10 the parts of the ST 
series but are very software intensive.  We traded manufacturing 
labor costs for software development costs - more expensive people 
and - as we all know - "software is never done".

It would be interesting if one of the contributors could add-in 
models and dates for Frederick modems.  Many predated HAL by quite a few years.

Bill Henry

PS:   The TT/L-2 was a great demodulator.  Some of the parts were 
very hard to find but once found and built, the demod had a VERY deep 
dynamic range.  The filters in the later ST-series were generally 
better but we gained a lot of satisfaction seeing all those "valves" 
light up (also heat for the shack).


At 06:46 PM 6/3/2009 -0500, Don Cunningham wrote:
>One word to the wise, replacing ST-6000's with the ST-8000A.  Listen to what
>Bill Henry and others are saying.  This TU was designed to fullfill a
>government contract, required to be "like" another brand of TU.  The
>ST-6000A is a FINE RTTY TU, designed for 60 and 100 wpm RTTY, with built in
>loop supply and tuning scope.  I have most of Hal's units by now, but
>consider the ST-6000 to be probably the "pinnacle" of their design for
>amateur RTTY (maybe if my ST-8000 (non A model) wasn't such a basket case, I
>would think it was better, hi)!!  Just MHO, but I bought a new ST-6000 for
>myself upon retirement, that was a special commercial low tone unit, and it
>far outdistances ANY other TU I own.  I have the ST-8000, ST-8000A (NIB one,
>so I paid a LOT more for it, hi), several ST-6000's and ST-6's.  All do what
>they were designed to do, just don't expect the last to be the best for
>amateur use.  If I'm wrong, some of you straighten me out, but in my shack,
>I'll never get rid of my ST-6000.  Off the soapbox, hi.
>73,
>Don, WB5HAK
>
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