[TenTec] RF Speech Processor "TX IMD"

[Kim Elmore]

This is interesting as I have a TS-930S. The old QST review showed that 
its TX IMD performance was middling at best: 3rd order is -25 dB and 5th 
order is -42 dB. Somewhere, I read that increasing the idle current on 
the PA from 1.3 A to 2.1 A helped the IMD performance "a lot" and so 
I've done that. I Also increased the driver bias to 70 mA.

The '930S also has a reputation of lots of TX and RX phase noise, though 
not as bad as the '940S. The TX phase noise is most easily identified 
clearly on CW. To help with RX, I put the 6 kHZ INRAD roofing filter in 
the 44 MHZ 1st IF and took it to FD last year for a battle-field test. 
Unlike before, the RX was now bullet proof, but I was worried about TX 
phase-noise QRM to the other stations. Early on, I did some testing with 
the other stations (using CW) to check for problems. I was very 
surprised to be told there were none (and I went to to the other 
stations to listen for myself)! I know for a fact the the TS-930S K0RF 
had would pummel me with phase noise if he pointed his antennas at me 
while I lived in Longmont, CO.

All that said, I never tried phone with it at FD but I'll give it a shot 
this year as a quick test to see if the IMD wipes out everyone else.

Kim N5OP

On 6/17/2013 1:07 PM, Barry N1EU wrote:
> On Mon, Jun 17, 2013 at 5:56 PM, Rick - DJ0IP / NJ0IP <Rick at dj0ip.de> wrote:
>
>> I understand how most of you guys who have never experienced this may be
>> finding it difficult to believe.
>> But once you've experienced it live, I guarantee you will jump on the
>> bandwagon with me.
>>
> I have experienced this in spades, especially from FT-1000 variants and
> TS-930S.
>
> 73, Barry N1EU
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