[ICOM] 7546 Pro II

[John Luthy]

It is my understanding that the Modern 746, 756 radios are rated at
100% (brick on the key) 100w duty cycle....

from Icom's web site:

"Inherited Properties From The 756PROII "

Highly stable transmitter
For a big, clear signal, the IC-756PROIII uses two 2SC5125 transistors
in the PA Unit. Along with superior IMD characteristics, these
transistors have plenty of power to allow for 100W full duty cycle
operation. Advanced design considerations along with an aluminum,
die-cast frame, and large cooling fan, help to stabilize the PA
circuit providing full duty cycle operation.

My 746 also claims to have a 100% duty cycle transmitter.

So my question is why did he only leave the transmit on for a short 10
min.?


John
cooling fans on hi
N7JL


----- Original Message ----- 
From: "JOE DE GREGORIO" <w3jo at msn.com>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Sunday, August 13, 2006 11:31 AM
Subject: Re: [ICOM] 7546 Pro II


My thoughts exactly.....Joe, W3JO



  You Know .......
   I wanted to ask the VERY same thing hi

  Dave Edwards wrote:

  > Um...was it a 'good' idea to leave a Pro 2 on full transmit for
10+
  > minutes??

  >
  >
  >>
  >>
  >> Hi all,
  >>
  >> A question for you guys. I was testing out a new dummy load to
see how
  >> "good" it was, last night. I tuned to 20m and FM and left the rig
on
  >> (into
  >> dummy load) for about 10+ minutes, at full power. The dummy load
  >> passed the
  >> test with flying colours! However, after the test, the Pro II was
  >> getting
  >> rather hot at the back and then refused to transmit on SSB, it
indicated
  >> very high SWR's which I could not correct with the "tune"
function.
  >> By this
  >> time I was on main aerial and not the dummy load. So I did a Bill
Gates,
  >> switched everything off, waited a few minutes and then switched
  >> everything
  >> back on and all worked just fine. Made a number of FB SSB
contacts on
  >> various bands.
  >>
  >> Is there a heat sensor within the rig that stops transmissions
until the
  >> unit has cooled down?? Just for information the receive side
worked
  >> perfectly.
  >>
  >> 73's de Tony G8DQZ

----
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