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Author Topic: ICOM 735  (Read 53155 times)
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iw5ci
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« on: March 08, 2010, 11:43:38 AM »

This is one of the best rice box radio for am service.
Just out of the box the received audio is extremely clean and the stock filter works very good.
You can switch the SSB filter on if there are very strong interferences by nearby stations.
The TX audio is very good 20W steady carrier and 800-100W pep without alc intervention. I have received many compliments for my audio.
I Think that also IC-751 works as good.
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N8ETQ
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Mort


« Reply #1 on: April 07, 2010, 02:12:13 PM »


Hi,
 Congrats on the new rig.  I wonder if you used a scope on it or
just backed down the audio for no ALC response.

/dan


This is one of the best rice box radio for am service.
Just out of the box the received audio is extremely clean and the stock filter works very good.
You can switch the SSB filter on if there are very strong interferences by nearby stations.
The TX audio is very good 20W steady carrier and 800-100W pep without alc intervention. I have received many compliments for my audio.
I Think that also IC-751 works as good.
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ke7trp
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« Reply #2 on: April 15, 2010, 10:41:31 PM »

YEs. a Friend has the 735.  Sounds wonderfull on AM for a transciever.  I was impressed with it.  Also the Yaesu 450 is nice on AM. No ALC cutting back. Just clear audio.

C
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n1uvi
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« Reply #3 on: February 24, 2012, 10:03:22 AM »

I realize this is an old thread but seemed like the logical place to post
I have found the 735 to be a nice little rice box for AM
with adjustment to the AM setup procedure as it is presented in the owners manual.
The manual tells you to set the AM carrier level at 40 Watts, by adjusting the AM carrier level control on
the rear of the rig. At this setting the ALC seems to be pre-engaged and mic gain seems very
difficult to adjust properly. The audio circuits in the 735 work well with ICOM mics for good communication
quality audio, but leave a lot to be desired when using better quality mics.
A better setup results when you adjust the AM carrier to 25 Watts, gives more headroom with no ALC involvement.
The SWR also needs to be low to prevent the ALC circuit from kicking in.
Injecting outboard audio into the Data input on the ACC socket on the rear of the rig, applies the outboard
audio directly into the balanced modulator through a single transistor buffer, completely bypassing the ICOM's audio circuits.
This allows you to apply EQ and limiting to the audio, and results in a superb sound for a rice box.


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WS4B
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« Reply #4 on: June 05, 2012, 09:52:55 AM »

Injecting outboard audio into the Data input on the ACC socket on the rear of the rig, applies the outboard audio directly into the balanced modulator through a single transistor buffer, completely bypassing the ICOM's audio circuits. This allows you to apply EQ and limiting to the audio, and results in a superb sound for a rice box.

Scott is absouletly correct. I recently acquired one of these little IC-735s, as their AM modulation has been noted to be above average for a little rice box. I use an iBox to connect my audio rack to a particular radio I am using, which is mostly a FT-102. Using this same application with a cable from the iBox to the ACC of the IC-735 resulted in excellent audio with my RF power adjustment down to about 20 watts.

Thanks Scott for the tip and advice, it works like a charm!
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N2DTS
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« Reply #5 on: January 28, 2014, 12:03:46 PM »

I had a few of these, nice looking small rig.
If I remember correctly, the pass band tuning works on AM which was uncommon on older rigs.

When I had mine, I adjusted the ALC so it did not kick in on AM, but it tended to put out more power then it should on other modes if you turned the power control all the way up.

The output power was not stable, as the rig warmed up, the power level will change.
I used to use it as an exciter and I found that out.
There is a mod to correct that I think, and you can make it general coverage TX as well, for CB or as a signal generator.

I think I will pick another one up, they are cute.

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