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Old June 26th, 2009, 00:12   #7
FlyGuy
 
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Join Date: Jul 2008
Location: FL120 and below...
Quote:
Originally Posted by Risc_Terilia View Post
Right now the GP68 Receives fine fron channel 2 of the T5930 when set to 460.595 so I guess that's the corresponding frequency for channel 2.

I can't find any documentation for the T5930, I have the manual but it doesn't tell you much.
That frequency does NOT correspond to any FRS/GMRS assignment. For the definitive list of FRS/GMRS frequency assignments, see the table on page 10 (PDF page 12 / 86) of this document. And for a pretty good discussion regarding conditional access squelch methods (CTCSS / DCS), see this link and reference the CTCSS table about 1/2-way down the page.


Begin rant...
For the record, I've been in the "radio business" for almost 20 years and it aggravates me silly (pet peeve) whenever I hear people talk about these so-called sub-channels! There is no such thing as a sub-channel dammit! That terminology is patently wrong...period! If two radios are tuned to the same frequency, say 462.6125 MHz (GMRS 6 / FRS 3) and they transmit simultaneously, it doesn't matter if one of them is using a 100 Hz CTCSS and the other is using 88.5 Hz, they are BOTH ON THE SAME RF CARRIER FREQUENCY and to a receiver listening on 462.6125 MHz, it will hear these two transmissions interfering with each other. The ONLY reason CTCSS and its digital descendant DCS were invented in the first place; or for that matter any other form of coded squelch control (DTMF, etc.), was to allow multiple radios to share the same carrier frequency within a common operating area without always hearing everyone else's traffic. It in no way affects the tuned RF carrier frequency and therefore does not add "extra or sub-channels" to your radio...it merely controls when/how your radio's speaker will un-mute during reception of transmissions on the tuned RF carrier frequency. Nothing more...period...end of story!
...End rant

Now, back to the task at hand...If you're doing these tests with both radios in close proximity to one another, you are probably overloading the front end of each radio every time you transmit causing it to respond even though it's off frequency...you need select low power and physically separate them to do these tests properly. Try at least 6ft or so to begin with. Also and as previously stated, you should disable all transmit and receive CTCSS/DCS on your GP68 and similarly on your T5930 before continuing. Then, referencing the frequency chart supplied in the link above, tune the T5930 to one of the 16 available FRS frequencies and then select that same frequency in the VFO of your GP68 -- Note: The GP68 has variable tuning steps so you should be set to either 12.5 kHz or 25 kHz spacing otherwise you may not be able to tune correctly. If everything's ok, you will hear yourself out of the other radio when you transmit a test.


Good luck,

'Fly

PS: Here's a link to the GP68 documentation/manuals/etc.
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Last edited by FlyGuy; June 26th, 2009 at 00:42..
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