[ICOM] IC 756 Pro III fuse over-heating?
Dan Cotsirilos K9DTC
k9dtc at comcast.net
Tue Dec 16 10:09:04 EST 2008
The Kenwood TL-992A provides a jumper with their amp and it measures 57 1/2
inches.
Dan K9DTC
----- Original Message -----
From: "Jim Hargrave" <w5ifp at gvtc.com>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Tuesday, December 16, 2008 8:40 AM
Subject: RE: [ICOM] IC 756 Pro III fuse over-heating?
> There is some merit to the length of the coax.
>
> Years ago I had a Collins KWM-1 and there was a note that recommended a 21
> ft length of coax between the KWM-1 and the 30L-1 linear. I don't know the
> theory on how they arrived at the 21ft. But it does make some sense. I
> just
> coil the excess up behind the desk and it makes a good RF choke between my
> FT-920/IC-735 and the Clipperton-L.amp.
>
> * 73's Jim W5IFP *
>
>
>
>
> >-----Original Message-----
> >From: icom-bounces at mailman.qth.net
> >[mailto:icom-bounces at mailman.qth.net]On Behalf Of Julio Peralta
> >Sent: Tuesday, December 16, 2008 1:02 PM
> >To: 'ICOM Reflector'
> >Subject: RE: [ICOM] IC 756 Pro III fuse over-heating?
> >
> >
> >Try changing the length of the coax between the rig and the input to
> the
> >amp. Sometimes the length of that cable will cause the rig to
> >reduce power
> >out until it determines the match is OK. I've experienced this myself.
> >
> >Julio, W4HY
> >
> >-----Original Message-----
> >From: icom-bounces at mailman.qth.net
> >[mailto:icom-bounces at mailman.qth.net] On
> >Behalf Of Phil Krichbaum
> >Sent: Tuesday, December 16, 2008 5:49 AM
> >To: ICOM Reflector
> >Subject: Re: [ICOM] IC 756 Pro III fuse over-heating?
> >
> > On Saturday night I had been running along working a bit on 10m CW
> >and then got a phone call. When I came back on the air some 15 minutes
> >later the Alpha 91B grid safety feature would trip after about two
> >seconds. I'd not had this problem previously in this contest
> >during some
> >good runs or ever before. I have two antennas and one is about
> >1.3:1 and
> >the other 1:1 and it didn't mater which antenna I used. I was running
> >the 756PROIII at less than 50w output. A little further checking and I
> >noticed when I first started to transmit I was getting less than QRP
> >output for 2-3 seconds before going to the set power level. This in
> >itself is a very undesirable feature for contesting not to mention not
> >having the amp available as it would trip as the power came up! Just
> >for the heck of it I tried loading on 20m and everything seemed OK. I
> >went back to 10m and same problem. I bypassed the Alpha and same
> >problem. I tried a different amp, same problem! I removed the
> >PROIII and
> >no problem with another rig and finished the rest of the
> >contest with it.
> > I'm using the Icom PS125 that came with my PROII "free" as a
> >closeout sales promotion (I certainly would not pay that much
> >for a 25 A
> >switcher). The PROII got taken out of service permanently with a
> >lightening surge that apparently came in the neutral side of the power
> >line. My PROII was off but this PS125 was left on (I've changed that
> >practice with the PROIII). I assume the PS125 means it is rated at 25
> >amps and there is a short power cord of about 12 inches with no fuses
> >and the 6 connector Jones type plug on the end. I suspect if there are
> >fuses, they are inside the PS125. I need to do some further checking of
> >the problem as to what bands are affected and at what power levels. A
> >friend had a similar problem on 6m last summer and it eventually went
> >way by itself. It seems I should try a different PS if the problem
> >persists and also take a look at the fuses in the PS125. Perhaps the
> >PS125 was damaged somehow when the surge came thru it. Damage
> >to the rig
> >also came in the rig control cable and CW keying jack from my desktop
> >that was connected but off. The HD in the desktop was toast. I
> >have also
> >picked up some 3 wire 250V 30A knife switches they use in Costa Rica at
> >the main house feed to shut off power to the house and will
> >install then
> >on my 120 and 240 lines into the shack prior to spring so there will be
> >no connection to the house wiring when I leave the shack assuming I
> >remember to throw the switch! I've also had my power provider install a
> >"Meter Treater" at my meter which has some big MOVs in it.
> > Anyways it seems like I need to check the PROIII with a
> >different PS
> >if this problem doesn't fix itself!
> > 73 Phil N0KE
> >
> >Jim Reisert AD1C wrote:
> >> I've had problems the last couple of weeks with my IC756 Pro III
> >> shutting down in the middle of transmitting. This weekend I traced
> it
> >> to the fuses (which were getting warm to the touch). I notice that
> >> my SS-30 power supply reports ~ 20 amps being drawn on transmit, and
> >> the fuses are rated at 20 amps.
> >>
> >> ** Is 20 amp draw during full-power transmit normal?
> >>
> >> ** Are the fuses supposed to be 20A?
> >>
> >> ** Should I replace with 25A fuses, or 20A slow-blow, or is there a
> >> bigger problem here?
> >>
> >> Thanks & 73 - Jim AD1C
> >>
> >>
> >>
>
> >------------------------------------------------------------------------
> >>
> >>
> >> No virus found in this incoming message.
> >> Checked by AVG - http://www.avg.com
> >> Version: 8.0.176 / Virus Database: 270.9.18/1850 - Release Date:
> >12/15/2008 5:04 PM
> >>
> >>
> >----
> >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/
> >No virus found in this incoming message.
> >Checked by AVG - http://www.avg.com
> >Version: 8.0.176 / Virus Database: 270.9.18/1849 - Release
> >Date: 12/15/2008 9:01 AM
> >
>
> ----
> 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/
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