The Ham Radio in Hawaii Page

Polly, the Simplex Repeater

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Note: the Radio Shack Simplex Repeater has been discontinued as of 2001. See comments below.

A non-technical, unscientific, biased new product report by Jim Yuen 2/15/1999.


 Radio Shack recently introduced a Simplex Repeater (RS 190-0345) for approximately $110.00. About the size of a small HT with an included cable, it runs off 4 AAA cells. Current drain is approx. 40 ma. The AAA cells lasts about two months.

Repeat time is 30 seconds (1/2 minute).

It can also run off 12 VDC or a separate 120 VAC "wall wart"

Shown on the left is an ICOM P2AT, the Simplex Repeater, adapter cable and box it came in.

What can it do:


Scenario 1: [Emergency occurs. Repaters are down. Can't talk simplex directly; RF path obstruction.]


Scenario 2: [Hiking in a deep valley; can't get signal out.]


Scenario 3: {think up your own]


Q & A:

Q: Will it repeat a repeater? A: Yes, you to set it to the input freq and listen on the output freq.

Q: Can it cross-band? A: Yes, you simplex repeat to your mobile and crossband from there.

Additional notes: (Oct, 1999)

Response to a letter:

I'm not familiar with the MFJ item. However there are about a half dozen simplex repeaters on the market ranging up to $300 each.

Many of them have additional options, but are more difficult to install.

The Radio Shack item has the advantage of extreme simplicity.

If you are installing a simplex trepeater to be used for long term, willing to spend $150-200, willing to interface the various lines (approx 10 power and signal lines) then there are better simnplex repeaters available.

If you want to put up a simplex repeater quickly, be willing to live with no automatic ID and accept a 30 second limit, then the Radio Shack is a reasonable choice.

Realize that simplex repeaters double the transmission time; once to record and once to repeat. If your area or town has heavy Ham use, extra time used might be resented. If there is no repeater around, then this is a great way to provide a service until such time as someone is willing to pay $1000-3000 to set up a duplex repeater.

Hope this helps.

Aloha and 73,



May, 2001

1) The Radio Shack Simplex Repeater has been discontinued as of 2001. There are a few commercial simplex repeaters ont he market, but at a considerably higher price.

2) Check out the email-list at

or send an email to

This is a groups of simplex repeater users and enthusiasts across the US. A good place for info and advice.

3) A simplex repeater consists of nothing more than a voice recording chip (30-60 seconds) and a timing controller (such as a Basic Stamp or PIC microchip). I suspect that we will soon see an article in 73 or QST on how to build one for less than $100. Anyone want to write the article?

73 and aloha,


Jim, WH6GS