RCI-2980 How do I adjust the frequency range?

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lasllamasvuelan
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RCI-2980 How do I adjust the frequency range?

Postby lasllamasvuelan » Monday 24th Jun 2013, 3:04

Radio Make and Model: RCI-2980 (NOT 2980wx)
PCB Number: E106527 SRF-C 94V-0 (This is printed on the main circuit board, and is preceded by a logo that is a combination of the letters RU.)
PLL Number: I've looked but I cant really find a definitive answer some IC numbers on the board are listed at the bottom of this post
Test gear available: DMM, my brain
Symptoms: Frequency range is 25.608-28.324 instead of the 28.055-28.455 listed in the manual
What is working: Everything else

What has been tried: I have gone through all modes channels and switch combinations with no change

Did it suddenly happen ?: I bought it used and it was like this
Anything else that may be of help?:
I'm pretty sure that the RX works because I get some whines and noise on a few channels even though I don't have an antenna hooked up.
Some pictures of my radio for reference-- http://www.earlandrews.com/cbrep.html
Manual Download -- http://www.rrcom.com/books%20and%20manuals/Rangers%20Books_Diagrams_Manuals.html
product page for newer version of the radio -- http://www.rangerusa.com/80wx.html
alignment procedures -- http://www.rangerusa.com/align2980.html
picture of adjustable parts for alignment procedure -- http://www.rangerusa.com/photos/2980lo.gif

Thanks for the help! Marc (No call sign yet, just took the test yesterday)

A chip labeled JRC Top line: 324D Second Line: M6042G
An M in a circle Top Line: MC145106P Second Line: QRU9705
M in circle Top Line: MC14008BCP Second Line: FUT9716
M in circle Top Line: MC14008BCP Second Line: FLA9702
Labeled TDA Top Line 6130-5 Perpendicular to that number written vertically is the number 646, Labelled "Germany"

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sonoma
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Re: RCI-2980 How do I adjust the frequency range?

Postby sonoma » Tuesday 25th Jun 2013, 5:59

looks as if it has been opened for all channels available for the freeband freq. here is a link to cbtricks for the mod to do what has been done. if you want to put it back stock reverse the freq mod.

http://www.cbtricks.com/radios/rci/rci_2980/rci_2980_freq_conv.htm

lasllamasvuelan
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Re: RCI-2980 How do I adjust the frequency range?

Postby lasllamasvuelan » Tuesday 25th Jun 2013, 11:20

Thanks I'll give it a shot!

lasllamasvuelan
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Re: RCI-2980 How do I adjust the frequency range?

Postby lasllamasvuelan » Thursday 27th Jun 2013, 14:10

So your suggestion worked, I'm now working with a 28 mhz radio, but it doesn't seem to have a working signal coming in from the mic, how could I test this?

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sonoma
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Re: RCI-2980 How do I adjust the frequency range?

Postby sonoma » Thursday 27th Jun 2013, 14:43

not sure I understand what you are asking about no incoming signal from the mic.
are you saying you are not hearing any body talking on the radio? you need to check what freq the radio is actually transmitting on with a external freq counter. you may have to align the radio now to trans and receive on the new freq you have reinstalled in the radio.
normally you have to align it when you do the mod you took out of the radio.
do you have the equipment to do what you are wanting to do?

lasllamasvuelan
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Re: RCI-2980 How do I adjust the frequency range?

Postby lasllamasvuelan » Friday 28th Jun 2013, 11:40

The 2980 has a built in PA system capability that allows it to turn of the TX and put your mic straight through a 3.5mm plug in the back amplified. When trying this I don't get anything out of the speaker except a little fuzz and the clack of me hitting and releasing the transmit button. The odd part is that if I rapidly hit and release this button with the echo option on it will echo this clacking noise, but my voice never gets through. What commonly goes wrong between the mic and the audio circuitry in a radio? (I've checked the wiring of the microphone itself and it is correct, though on the inside of the radio I don't know if it is wired correctly, as the RX pin is not hooked to anything, and there are three ceramic disc capacitors soldered between one of the microphone leads and the chassis of the radio.

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sonoma
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Re: RCI-2980 How do I adjust the frequency range?

Postby sonoma » Friday 28th Jun 2013, 12:10

I am getting the feeling that you do not have a watt meter or any test equipment to verify the radio is even working at all.
can you verify anything other than the PA funtion?

lasllamasvuelan
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Re: RCI-2980 How do I adjust the frequency range?

Postby lasllamasvuelan » Friday 28th Jun 2013, 15:59

Built in watt meter jumps when I hit transmit button, and responds proportionately to adjusting the TX power or the RF gain. I'm going to a shop tomorrow to use an oscilloscope to follow the alignment procedure. When it was operating in the 25 mhz band area, there was one channel that always put through a signal that made the watt meter jump, and it did get stronger and weaker as I used the clarifier. this whine is not present on any channel or settings combination. To answer your question, all Ihaveright now is a DMM, though I have an external watt meter, and frequency counter on teh way with an antenna and dummy antenna

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sonoma
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Re: RCI-2980 How do I adjust the frequency range?

Postby sonoma » Friday 28th Jun 2013, 18:26

you need a scope, freq counter and signal generator , dummy load and watt meter to verify the radio is actually working. it is even good to have another radio close by to listen to the radio you are working on also just to hear how it sounds so you will know what kind of signal you are putting out for someone else to talk to you. the radio can show it is working but if the signal out is trashy no one can talk to you at all.

lasllamasvuelan
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Re: RCI-2980 How do I adjust the frequency range?

Postby lasllamasvuelan » Saturday 29th Jun 2013, 3:47

I'm going to a shop today that has said tools. What commonly goes wrong with the mic/audio in circuitry so that I can check it?


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