[UK-CONTEST] FT1000MP AGC

[Gavin Taylor GM0GAV]

Dave, Chris etc

Like Chris I have a keen interest in the original 1000MP! I also did the Inrad AGC mod around the same time as Chris (In fact at Chris's QTH I seem to remember). It seems to make a difference, as Chris comments you only really notice the difference when you go back to using a virgin MP.

For interest here is part of an email I sent to Andrew ' NWG a couple of months ago, it details what I have done to my MP.

 
It is an original MP that I have, 1996. Here is a quick run down on what I have done to mine :-

Did the K9AN cap mod plus the Inrad agc mod in 1998, good improvement on cw and less hiss.

Last month I did the Inrad key click mod. Cleans up the keying a bit without getting too soft. I know doing Multi multi at GM7V with all MPs the interstation interference was very clicky.

Then did the Inrad roofing filter last month, brilliant £100 well spent. 

Then 2 weeks ago changed the filter diodes to PINs. Have a look at http://www.mods.dk/view.php?ArticleId=2992 It will improve the 2nd and 3rd order IMD  and he says that it will also reduce the noise floor. In reality you will probably not notice much of a difference except in contests where there the LF bands are full of huge signals. For example I was using a 402-CD at 75ft this weekend, only once used the IPO and never the attenuator.
It is quite easy to do, the HP diodes are very expensive but you can get much cheaper PINs like the MI204 from Icom UK. I fitted the HP diodes only because a friend gets a huge discount from Farnell. I fitted 24 x MI204s to my IC-765 last year, they worked out at about 40p each from Icom UK.


73 Gavin
GM0GAV



----- Original Message ----- 
From: "Chris Tran ZL1CT" <zl1ct at gm7v.com>
To: "UK Contest Reflector" <uk-contest at contesting.com>
Sent: Tuesday, December 28, 2004 9:00 PM
Subject: Re: [UK-CONTEST] FT1000MP AGC


> Hi Dave et al
> 
> FT-1000MP receivers are one of my favourite subjects - I've put up with the
> mediocre performance since 1997 - Santa was going to bring me an Orion but
> couldn't find me here in N.Z.   ;-)
> 
> At the club station ZL6QH the FT-1000MP has a similar problem to yours -
> pile-ups sound 'fuzzy' and it is difficult to pull out one station - other
> operators look at you when you complain and you can see them thinking 'he's
> losing it' !  My own MP sounds quite different under pile-up conditions -
> much easier to select one callsign.
> 
> I've done only one AGC mod - not quite sure what it was for but it was a
> early recommendation - add a 0.47uF C and 10k R (connected in series) across
> C2026. I think www.w8ji.com or www.va3cr.net may have newer AGC mods ?
> 
> 73
> Chris
> ZL1CT/GM3WOJ
> 
> 
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