TopBand: InRad FT1000MP Mod: Good for 160?

[John Kaufmann]

At 01:45 PM 12/25/98 -0500, Earl W Cunningham wrote:
>
>Tyler Stewart, k3mm@erols.com writes:
>"This mod will do absolutely nothing for you on 160 meters."
>=====
>I vehemently disagree with that statement!  I also thought that the band
>noise on 160m dictated weak signal readability rather than the receiver's
>noise floor.
>
>I was disappointed after spending more than $2500 for my new MP to find
>that my 18-year-old TS-830S  still heard weak CW signals on 160m slightly
>better than the MP.  I was elated to find that, after installing the
>INRAD front-end mod in the MP, that the MP was slightly better than the
>TS-830S.
>

I had the same experience as Earl.  My TS940S actually outperformed the
1000MP when listening on my Beverages without the Inrad mod.  As I stated
in my earlier post, my 1000MP simply doesn't have quite enough gain for a
Beverage, even on 160.  The radio's internal noise is easily audible over
external atmospheric noise.  Another sample of a 1000MP which I tried had
exactly the same performance.  The TS940S had quite a bit more gain and
never had this problem.  Switching in the 1000MP's tuned preamp front end
actually makes matters worse because the gain and sensitivity drop even
more in the "tuned" mode below 40 meters (this has been verified in ARRL's
lab measurements).  Also, switching in the IPO bypass or more front end
attenuation reduces sensitivity as a tradeoff for more dynamic range.

Having said all that, the Inrad mod improves matters quite a bit.  Keep in
mind these comments apply only if you listen only on a low-gain receiving
antenna, like a Beverage (which I always do on 160) and not your transmit
antenna.

73, John W1FV

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