>Richard Measures (AG6K) wrote:
>
>>I had reports that my TS-440S was not as clean as my old TS-830S, so I
>>decided to try and do something about it. Since most IMD occurs when the
>>transistor is at maximum peak collector current - when Vc is close to its
>>minimum, I figured that giving the transistors more "head-room" might
>>help. The 440 is speced at 12v to 16v, so I increased Vcc to 16v and got
>>on the air. Several friends reported that the IMD was reduced with 16
>>volts. [note - the electrolytic caps in the 440 are rated at 16wv and
>>the output transistors are rated at 18VDC of Vcc]
>
>For what little it may be worth, I am well aware of many anecdotal
>experiences with the TS-430/TS-440/TS-140 series transceivers in which
>they'll get VERY nasty sounding if run at a MINIMUM supply voltage of
>anything less than about 12.6VDC.
>
>Many (good) ops tend to assume that their power supplies (even Astrons) are
>always set up so they put out 13-14VDC. Unfortunately this is not a safe
>assumption. They're usually the ones who have gotten burned with poor
>reports.
? As long as rotten splatter doesn't go outside the band, it is not
against the Part 97 rules.
>
>I'm not sure I'd run my rigs at 16VDC, but I'd sure suggest 14VDC (under
>load!) as a minimum supply voltage
>
? My 440 has so far operated ok on 16v for a couple of days. Time will
tell if it will last.
>
cheers, Tom
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
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