[ICOM] Internal PS question

[Mike Olbrisch]

You have it right Gary.  The 740 was a ham-band only RX, and at the time the
general coverage radios didn't have as good a receiver and the ham-band only
rigs.

Vy73 - Mike - KD9KC.
El Paso, Texas - DM61rt.
W5-SOTA Association Manager.
W5-SOTA info: www.qsl.net/kd9kc/




-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of Gary Fiber
Sent: Wednesday, March 07, 2012 08:54
To: ICOM Reflector
Subject: Re: [ICOM] Internal PS question

  Icom ran the low level of transmit RF through the speech processor 
switch. a Common failure mode was no RF out. So I would have the callers 
to support work the speech processor switch several times and generally 
that would restore the 740 to full transmit out.
Though the best result was to replace that switch. The 740 was not 
involved with the trimmer cap troubles as later rigs were so far as I 
remember. Seem to me it was ham band only receive but it been a few 
years since I've worn the support hat for Icom.

Gary K8IZ

On 3/7/2012 6:39 AM, Mike Olbrisch wrote:
> I stopped using my 740 when I got a 781.  No question which was better
> there.
>
> Truth is, the 740 had one of the best receivers of its time.  If I had to
> use another 740 in the shack, I wouldn't feel too bad about it.
>
> The speech processor switch is prone to failure. I had replaced mine, and
> when I sold it an extra switch went with it.  I am not so sure about the
PLL
> caps, I never had a problem there.
>
> Over-all, it was a great radio.  I never regretted owning it, I sometimes
> regret selling it.  But with a 781 w/ AT-500 and 2KL, 703, 706, 551D,
820S,
> full-stack 901A and FT-817 in the shack, I needed the space.
>
> Vy73 - Mike - KD9KC.
> El Paso, Texas - DM61rt.
> W5-SOTA Association Manager.
> W5-SOTA info: www.qsl.net/kd9kc/
>
>
>
>
> -----Original Message-----
> From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net]
On
> Behalf Of John G.
> Sent: Wednesday, March 07, 2012 07:29
> To: ICOM Reflector
> Subject: Re: [ICOM] Internal PS question
>
> So is the Icom 740 still a pretty good performer overall?  Any typical age
> related problems that show up with it affecting its reliability?
>
>
> ----- Original Message -----
> From: "Mike Olbrisch"<mike-2007 at elp.rr.com>
> To: "'ICOM Reflector'"<icom at mailman.qth.net>
> Sent: Wednesday, March 07, 2012 2:09 PM
> Subject: Re: [ICOM] Internal PS question
>
>
>> Good morning Steve and others.
>>
>> I have three of those internal power supplies.  They are switchers,
>> running
>> about 20 KHz IIRC.  The first one is inside the IC-PS30 case.  The second
>> is
>> in like-new condition and ready to replace the first when it dies.  The
>> third is in need of rebuild, it quit and was replaced by the first.  I
>> have
>> the parts, I currently lack the time.
>>
>> I have found them to run fairly cool under load, and I cannot say I have
>> ever heard any noise I could attribute to those supplies.
>>
>> When I have had them fail, I usually just re-cap them and they seem fine.
>>
>> I had a fully-loaded IC-740 several years ago.  When I tried to sell it
>> as-is I got offers of like $300 on it.  So I stripped it out, sold the
>> bare
>> radio for $300, sold the filters and other accessories for another $400
or
>> so.  I think I still have the keyer board around here somewhere, no one
>> seemed to want it at the time.  So I tossed it in a box of junk up in the
>> storage loft above the garage.  I kept the internal supply as a spare for
>> the PS-30, same guts.
>>
>> Anyway - those supplies are pretty good in my book.
>>
>> Vy73 - Mike - KD9KC.
>> El Paso, Texas - DM61rt.
>> W5-SOTA Association Manager.
>> W5-SOTA info: www.qsl.net/kd9kc/
>>
>>
>>
>>
>> -----Original Message-----
>> From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net]
>> On
>> Behalf Of Steve
>> Sent: Tuesday, March 06, 2012 23:04
>> To: ICOM Reflector
>> Subject: Re: [ICOM] Internal PS question
>>
>> I was merely inquiring if they really used switching
>> type supplies knowing how bad they can be for noise.
>>
>> ----
>> 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/
>> To support QSL/QTH.net: http://www.qsl.net/donate.html
> ----
> 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/
> To support QSL/QTH.net: http://www.qsl.net/donate.html
>
> ----
> 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/
> To support QSL/QTH.net: http://www.qsl.net/donate.html
>


-- 
Gary Fiber K8IZ
GROL PG-19-6691 with Shipboard Radar Endorsement
Washington State Resident

----
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/
To support QSL/QTH.net: http://www.qsl.net/donate.html