SM-120 2 part question. 1)OOB hack, 2)repeater

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ltec123
Posts: 50
Joined: Mon Sep 24, 2001 4:00 pm

Post by ltec123 »

Hi guys,

1) When hacking a SM-120 470-490 to work below 470, does it degrade the RX/TX quality?

2) Can I use 2 SM-120's back to back, making a repeater?

Thanks, LT

PS Also what is bi-direc on a dual mobile repeater? I understand that it does TX/RX at the same time but, what are my adavantages of doing that?
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Post by Will »

Do you want a repeater?
Do you want a "extender", a bi-directional repeater?
I make the module for the radios to become repeaters, it is plug and play for most radio combinations. PM for more details.
April
Posts: 385
Joined: Thu Jan 24, 2002 4:00 pm

Post by April »

SM120s can be used in repeater and extender / link applications. The SM series radios have a very poor heatsink for the transmitter which severly limits the power output capabilities.
Will's module works well on the SM radios, I have set up some two watt repeaters and links with them on SM50/120s.



<font size=-1>[ This Message was edited by: April on 2002-03-13 17:54 ]</font>
ltec123
Posts: 50
Joined: Mon Sep 24, 2001 4:00 pm

Post by ltec123 »

Hi, thanks for the help.

If someone can explain me a bit more what a extender is vs. a repeater, I would really appreciate it.

Thanks much!

<font size=-1>[ This Message was edited by: ltec123 on 2002-03-13 19:51 ]</font>
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Post by Will »

Fairly simple.

Repeater is where one radio receives and another radio transmitts the receivers audio out on a different frequency in the same band, like 468 receive, and repeated on 463 mhz.They usally have drop-out delay on the transmitter (repaeter tail).

An Extender is when two radios, usally on different bands, like one on VHF, other UHF,
and when one radio receives, the other one retransmits the audio. And the reverse is true, the second radio's receiver audio is retransmitted on the first radio.
BUT NOT AT the same time. This is usally used in vehicle to allow the base station dispatch radio in the vehicle to be retransmitted out on the other radio accessed by the driver's portable when in a building, down the hill on a fire/rescue ect;. It "extends" the portableradio's range to that of the main radio in the vehicle. Also known as a "Bi-directional repeater.

A link is when two fixed radios "hop" a signal thru a location on to another point.
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