VHF Spectra Range 1/Range 2

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gwilkinson
Posts: 13
Joined: Thu Aug 25, 2005 8:16 am

VHF Spectra Range 1/Range 2

Post by gwilkinson »

I was given a vhf spectra to play with. As it is a range 2 radio it will not work below 146 mhz. It receives fine on 144.39 but will not tx. So I decided to use the lab program to change the byte that says it is a range 2 radio to tell the radio that it is now a range 1 radio. Now it will receive and transmit just fine on 144.39. But, when I program in a frequency of 146.52 I get a Synth Unlock error code when I try to transmit on the 146 freq. Any ideas? Or am I going to have to settle for a 144 mhz only radio? BTW, changing the code back to range 2, 146 works fine and 144 again does not work.

Gale
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: VHF Spectra Range 1/Range 2

Post by Will »

The stock range 2 VHF Spectra will work down to 142 no problems.

Changing, bitbanging, the range 2 to be seen as a range one will cause the problems you describe.

Step ONE, change it back to a range 2.

The later RSS does allow you to program frequencies down to 142 mHz.

If you radio has FAIL001 below 146 then there is other problems.
gwilkinson
Posts: 13
Joined: Thu Aug 25, 2005 8:16 am

Re: VHF Spectra Range 1/Range 2

Post by gwilkinson »

No, it is not a fail as such, the radio just doesn't put out any power (maybe 1 watt), though the receiver works just fine. I did put back to its normal seting as a range 2 radio when I saw that it was not going to work. Any ideas on this?

Gale
jmr061
was KB9KST
Posts: 3176
Joined: Fri Sep 14, 2001 4:00 pm

Re: VHF Spectra Range 1/Range 2

Post by jmr061 »

Is it putting 1 watt out through the entire range?

Jason
gwilkinson
Posts: 13
Joined: Thu Aug 25, 2005 8:16 am

Re: VHF Spectra Range 1/Range 2

Post by gwilkinson »

no, that is the strange part. 146.52 is normal. But 144.39 is down.

Gale
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: VHF Spectra Range 1/Range 2

Post by Will »

Gale,

Maybe the harmonic filter is causing the loss of tx power.

Check the control voltage to the first stage in the transmitter PA on both frequencies.
gwilkinson
Posts: 13
Joined: Thu Aug 25, 2005 8:16 am

Re: VHF Spectra Range 1/Range 2

Post by gwilkinson »

OK, will have to give that a try on Monday (busy busy busy the next few days..). One question, as it did put out full power on 144.39 when I had it thinking it was a range 1 box, would this mean that maybe a full alignment might be a fix. Assuming that I see a major difference in the voltage you said to check.

Gale
w8one
New User
Posts: 2
Joined: Sat Mar 05, 2011 9:19 pm

Re: VHF Spectra Range 1/Range 2

Post by w8one »

i read somewhere that changing the range in the rss changes the electrical path the radio uses to feed the vco and if set wrong the parts a not there to use.
w8one
New User
Posts: 2
Joined: Sat Mar 05, 2011 9:19 pm

Re: VHF Spectra Range 1/Range 2

Post by w8one »

Here is what i read http://www.batlabs.com/moflag.html go to the bottom to Spectra bandsplit.
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