R7100 Help: Does anybody knows what is this mod on R7100?

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Notescucho

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Hello I'm thinking about buying an Icom R7100. There is s seller who offers me this one (see the picture). Does anybody knows what are these switch and numbers on the left side of the rear panel?

Thank you so much.
 

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VE2XWA

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Hello I'm thinking about buying an Icom R7100. There is s seller who offers me this one (see the picture). Does anybody knows what are these switch and numbers on the left side of the rear panel?

Thank you so much.

They removed the internal ac power supply. The unit can only powered by DC.


Sent from my iPhone using Tapatalk
 

majoco

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Unless the seller can provide you with a detailed description and diagrams of the modifications, I wouldn't touch it with a bargepole. The R 7000 and 7100 are complicated enough as it is, never mind if it has some weird mods done to it.
 

Notescucho

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Thank you very much friends, your opinions help me a lot. Now I have to make a decision to buy the correct equipment for me:
- a new sdr play (200€) and fight with a computer.
- a new bct15x (200€) and fight with an ugly non visible menu
- a used ic-r7100 (400€) much more gentle in my opinion but with the risks of a second hand equipment.

Some times I get tired of myself ;-). Suggestions are welcome.

Thank you all.
 

AK9R

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The R7100, in standard form as sold in North America, could be powered from 12 volts DC or 120 volts AC. There is an internal power supply that converts the 120 volts AC to 12 volts DC to run the radio. The 12 volts DC goes in through the 4-pin Molex connector. If you want to use the internal power supply, you must have the jumper plug inserted into that 4-pin Molex. That's the plug with the red wire in the non-modified photo.

The internal power supply does generate a bit of heat. Using an external power supply keeps that heat out of the box. It looks like someone decided to remove the internal power supply, maybe because it failed, and add some other features. I like prcguy's idea that the selector switches are for CTCSS decode. I'm going to jump to the conclusion that the 5-pin DIN connector was for some sort of remote control feature that was added.

I agree that unless the seller can document the modifications, I would not buy that radio.
 

n2pqq

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Did you ask the seller what the mods are for ?
 

majoco

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If the 7100 is much like the 7000, it already has a remote feature - not very exotic, it only does 100 frequencies, not the ones already in the radio - although you can be cunning and have more than one instance of the software running under different names - not at the same time of course. You can make your own interface - and the interface works with the Yaesu VX2 and later in that series.
 

bob550

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The apparently mechanical switching wouldn't seem practical for CTCSS as you'd only be able to set one code at a time. That is unless this option allows the code to be written to memory somehow. Also, the switching panel may be on the rear out of necessity, but it suggests a feature that doesn't require frequent adjustment.
 

AK9R

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The apparently mechanical switching wouldn't seem practical for CTCSS as you'd only be able to set one code at a time.
Hmmm...new around here? ;)

I think FM mobile and handheld radios with synthesized frequency selection (as opposed to crystals) became popular in amateur radio during the 1980s. Originally, these radios included no provisions for sending a CTCSS tone. The aftermarket met the need with small PC boards that could be installed inside these radios. These aftermarket boards had DIP switches for manually setting the tone that would be transmitted whenever the radio was keyed up. No matter what channel you transmitted on, the same CTCSS tone was sent.

The Japanese radio manufacturers then started including CTCSS encoders in their radios. But, the microprocessors used in these radios were limited, so DIP switches were used for manual CTCSS tone selection. No matter what channel you transmitted on, the same CTCSS tone was sent.

Yes, if the switches on the back panel of this radio are for CTCSS decoder selection, it's not very practical. But, without documentation, we really don't know what these switches do.
 

bob550

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Sorry, I guess I'm part of the post-dip switch era. :) My only experience with the installation of an aftermarket CTCSS tone board was the BC-002 for my 890XLT. And that didn't use dip switches as it was programmable through the main keypad.
 
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