[ICOM] Internal PS question
John G.
af5cc at fidmail.com
Wed Mar 7 17:38:57 EST 2012
Glad to know it doesn't have the trimmer caps problem. I didn't think it did
but wasn't sure. I see that Mike already answered the question about whether
it was general coverage or not.
----- Original Message -----
From: "Gary Fiber" <gfiber at comcast.net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Wednesday, March 07, 2012 3:53 PM
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
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