[ICOM] 706 MK2G Finals - possible replacements?

[AA6DX - Mark]

Try here .. is this any help?  Or am I missing something... entirely 
possible .. HIHI...
http://www.1sourcecomponents.com/partinfo/srfj7044.htm
Mark Nelson  -  AA6DX

mailto: AA6DX at ARRL.NET

----- Original Message ----- 
From: "Clif Holland" <clif at avvid.com>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Wednesday, January 10, 2007 1:44 PM
Subject: Re: [ICOM] 706 MK2G Finals - possible replacements?


I ran into this problem a while back. Motorola discontinued the 7044 for
whatever reason leaving Icom high and dry. Something like in the middle of a
production run and oops no more transistors. I could not find a sub for it,
no-one lists anything. I was told the replacement board has electrical
differences. They are limited as to replacements because they have to use
the existing heatsink That being said since the 7044's from Icom were almost
$100 each the whole assembly for $300 is not a bad deal. Last time I
conversed with them the board wasn't available, maybe they have cured that
problem anyway.

Clif Holland KA5IPF
www.avvid.com




----- Original Message ----- 
From: "Dan Doss" <kg0mm at arrl.net>
To: <icom at mailman.qth.net>
Sent: Wednesday, January 10, 2007 2:16 PM
Subject: [ICOM] 706 MK2G Finals - possible replacements?


> Hello all,
>
> First off let me say that I'm relatively new to the reflector so please
> excuse any redundancies in what follows on the subject. That being said -
> I, like many on the reflector, have had to replace the HF finals on the
> 706. The last time I did, the original SRFJ7044 MosFET's were available
> from Icom, albeit at a premium price. A call to Icom yesterday brought me
> aware of the fact that these transistors are available only for repairs
> made by Icom services centers. This fact may already be known by many, but
> was a little disconcerting to me. I was told that the only way one (an
> individual) could repair their blown finals was to buy a complete new PA
> assembly. I was given a part number of 98414684 (which is available) and
> lists for $293.33. Yikes! I was also told that the finals used on the new
> PA assy were not "compatible" with the older boards. When asked if this
> was due to electrical or physical reasons, the nice parts lady indicated
> that she thought is was because of physical differences. This was not
> confirmed by an Icom tech.
>
> After a bit of research, I found that the SRFJ7044 MosFET is packaged in
> what Motorola/Freescale/MA-Com calls "Case 316-01". This is a 6-legged
> package with is attached to the heatsink with two screws. Other similar
> MosFET's (such as MRF150) use a stud-mount style package. I have not seen
> what transistors are used on the new style PA. There may very well be both
> physical and electrical differences between the two parts. Without having
> data sheets on either, it's difficult to ascertain if an off-the-shelf
> (and still in production) replacement part exists. I seriously doubt that
> Icom would be the least bit interested in locating such a device.
>
> Not to be too long winded about the subject, but at a repair cost of
> nearly $300, it might be worth it to the group if we could attempt to
> locate another non Icom-specific part to repair our rigs with. If anyone
> has access to a network analyzer (and a spare '7044), it should be
> possible to characterize the old part so that a potential replacement
> could be researched. A quick search on MA-Com's website yielded a couple
> of transistors of the same power class and package that _might_ have
> similar characteristics (s-parameters, etc) to the '7044. I would be
> willing to use my 706 as a "test bed" for the cause if we can get some
> specs on the old part.
>
> Let me also say that I am not in the business of repairing radios for
> hire. I just hope to spark some interest so that we might be able to keep
> our venerable 706's running without having to break the bank for repairs
> or as might be hoped by some, buying new rigs...
>
> Any thoughts???
>
> 73,
> Dan - KG0MM
>
>
> ----
> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
>
>


----
Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
Icom Users Net: Sundays, 1700Z, 14.316 MHz
Icom FAQ: http://www.qsl.net/icom/