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meanwhile out in the garage ...

Quite the unique bit of kit. I'm building this to replace the "loaner to the new ham" radio that was purchased rather than returned.

My roommate has one, Kari has one, I have one, and another is promised to the next offspring to acquire a license.

The best and the worst of this radio is it's general coverage receiver and it's through hole design.

The receiver suffers from listening through the same filters that it transmits through. Consequently it hears a bit better in the ham bands while its sensitivity and selectivity suffer a bit for its broad banded receiver.

The through hole design makes it easy to work on while having quite the heat loading of its densely packed components.

Several versions of the 630M modification are available for those that wish to drive 475KHz RF plasma generators into a few tenths of an ohm radiation resistance :LOL:
http://alain.st.free.fr/site1/aspicsite/IC-735/500KHZ/735-630m-mod.pdf

Disclaimer: The above link includes the general coverage transmit modification. I neither condone or decry this modification, HOWEVER, AM, FM, or digital modes above 25 watts put the PA at risk. For AM, direct injection is well covered by the folks at http://amfone.net and/Amforum/index.php
...This as well as the negative voltage ALC mod to tame the transmitter.

For the 11m user, please use your radio responsibly, or not :whistle:

Fun radio , SM attached.
 

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  • IC-735 Service Manual.pdf
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To install the IFace card inside the ICOM IC-735 follow the steps below.


The IC-735, like other radios, has a fairly complex configuration and uses different intermediate frequencies. We are interested in having a “wide band” signal, so it will have to be picked up before the main band pass filter. The sequence of operations to be performed to obtain a bandwidth sufficient to realize a panoramic receiver around the chosen IF frequency (70.451 MHz) is shown below. The path of the TX and RX signals is partly separate, so the PTT command to disable the IFace during transmission may not be necessary. The following images show the point where the IF signal will be taken and the power supply.




Now we need to locate the points where to connect the electric cables to the IFace. The following images illustrate where to get the various signals on the MAIN UNIT.




Great instructions but
https://www.sdr-kits.net/index.php?route=product/category&path=66_73_84
better price :)
 
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To install the IFace card inside the ICOM IC-735 follow the steps below.


The IC-735, like other radios, has a fairly complex configuration and uses different intermediate frequencies. We are interested in having a “wide band” signal, so it will have to be picked up before the main band pass filter. The sequence of operations to be performed to obtain a bandwidth sufficient to realize a panoramic receiver around the chosen IF frequency (70.451 MHz) is shown below. The path of the TX and RX signals is partly separate, so the PTT command to disable the IFace during transmission may not be necessary. The following images show the point where the IF signal will be taken and the power supply.




Now we need to locate the points where to connect the electric cables to the IFace. The following images illustrate where to get the various signals on the MAIN UNIT.



 
I have a ICOM 725 That stays Keyed up Whether the transmit button is in or out. even when the mike is un pluged Looking for poipnters??
 
index.png
 
No, well, - er - no. More like A piece of Damp String tied to Channel 19 Chrystal and a 9-Volt Radio Shack Battery...

Easy to construct, you just don't get much done because some else is having all the fun using theirs...;)
 
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Does anyone else leave a Kop thread and feel like that string hanging off an old towel?

Just too much to process.


Able men in the company of The Kopcicle find it wondrous he seems to vanish then re-appear a distance away.

He’s just a tiny bit overclocked.
Compared, that is, to those wholly mortal.

My company sends me “mandatory safety training” in the form of videos. I tell them my mind hasn’t worked that slowly since puberty hit. I decline. They steam.

.
 
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He’s just a tiny bit overclocked.
.

"Tiny" is an understatement...

He's like the Sugar in Shirley Jones' "There's nothing like your 32nd Cup Of Coffee in the Morning..."

IN the Memory Map of Life...

The Question of
upload_2020-5-6_8-26-23.png
comes up...​

He answers

PRETTY BIG

OR...

While the world runs along at 32nS - he's waiting in the 10nS 8 Giga-Byte Cache - having a refill...
 
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minipa_sch.jpeg

So, apply 50v and what blows up first? I know the regulator won't take 50v and a "few" of the caps would vaporize...

For those of you that have been following along at home, yes, I'm contemplating replacing the IRF520/530 with the MRF101's.
Ignore the pinout for now (got that fingered) . The omron relay is available with a 48v coil. Looking at the PTT transistor breakdown voltages...
 

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