Yup,
EA8BNP shows a ST1200 he converted to the ham bands at
http://www.geocities.com/metbee/isaac/introen.html, though
I doubt he is using an FT817!
Gerry Hull
Hull Computer Consulting
POB C, Greenfield, NH
Home Office: 603-547-8327
Voice Mail/Fax: 866-823-5473
email: windev@inetmarket.com
> Gentlemen,
>
> This could probably also be done using 4 x 4CX250 or similar tubes in
> parallel.
>
> The Swedish ITT Marine subsidiary, Standard Radio & Telefon AB, manufactured
> for decades the ST1200/ST1400/ST1600 family of shipboard transmitters. Later
> production of the ST1600/ST1680 used a 20 W class A solid-state drive module
> to drive the tube PA
> with 4 x 4CX250B in a neutralized AB1 circuit with RF negative feedback, to
> obtain a "decent" IMD even at full PEP (1500W)
>
> I have not heard an ST1600/ST1680 on the air for ages, but recall that IMD
> measurements usually were in the -30 to -34 dB region from each tone, and the
> adjacent channel noise power ratio usually measured in the -45 dB region when
> driven to 1500W PEP.
>
> An used ST1600 or its Debeg or Mackay equivalent, or the S.P.Radio (Sailor)
> T-1127
> that used 8122's in parallel, should not be too difficult to find after the
> abolishment of shipboard Morse.
>
> Removing some of the grid swamping would probably reduce the drive
> requirements to
> the FT-817 class even without using the drive module, but I find it somewhat
> odd to use a 200 kg "afterburner" with a pocket-size rig...
>
>
> 73/
>
> Karl-Arne Markstrom
> SM0AOM
> ==================
> Senior Radio Engineer
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