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MTS2000 uhf VCO adjustment
Posted: Thu Mar 13, 2008 12:10 am
by motoguy
gday all, i have a Model 2 MTS2000 flashport here and it transmits fine up to 477.100 but id liek it to reach 478.XX mhz i know its possible to slighlty tweak the vco to do so if someone could please let me know how to do so it would be greatly appreciated . thanks in advance for your help .
Re: MTS2000 uhf VCO adjustment
Posted: Thu Mar 13, 2008 5:24 am
by Mfire39
motoguy wrote:it transmits fine up to 477.100 but id liek it to reach 478.XX mhz i know its possible to slighlty tweak the vco
Have you tried programming the 478.xxx freq in it? Does it give a fail on the display when you do? If it stays locked, I wouldn't tweak anything...
-Marc
Re: MTS2000 uhf VCO adjustment
Posted: Thu Mar 13, 2008 6:01 am
by motoguy
ok all, i only have to get another 75 khz up from where i can currently TX... how can i accomplish that 3 extra 25khz steps? lol such a pain hehe
cheers
Re: MTS2000 uhf VCO adjustment
Posted: Thu Mar 13, 2008 6:03 am
by Mfire39
Did you not read my question?? Have you tried programming your 478.xxx freq in the radio?? What does it do when you try to program that freq in?
-Marc
Re: MTS2000 uhf VCO adjustment
Posted: Thu Mar 13, 2008 6:27 am
by motoguy
the radio transmits for approx 3 seconds then flashes Fail 001 on the lcd with a beep then goes back to the alpha chanel name..it RX fine at well above 480mhz...
Re: MTS2000 uhf VCO adjustment
Posted: Thu Mar 13, 2008 6:31 am
by Mfire39
Ok... Thanks for finally explaining that...
-Marc
Re: MTS2000 uhf VCO adjustment
Posted: Thu Mar 13, 2008 8:16 pm
by motoguy
and as the hot weather comes today i cant transmit at 477.000 now its getting lower? anyone have any idea? i need thisa radio working. thanks
Re: MTS2000 uhf VCO adjustment
Posted: Thu Mar 13, 2008 8:59 pm
by AEC
In order to make the 403-470 radio play up higher than it was designed for, you will have to adjust the VCO crossover frequencies that match the upper band split you intend to use the radio in, but should it fail, write down those adjustments BEFORE you reprogram the VCO again.
You must also do a complete alignment of the RF section as moving the operating frequencies of the radio upward, this will be a 'must do' for service requirements and to keep the radio from generating spurs and harmonic outside the band.
One sensitive area you MUST use a service monitor on, is the RX filters(bandpass) as they need to be set properly for the radio to receive in the low .25uV or lower area for the best receiver quieting at 12dB SINAD.
There's a lot to do to that radio to make it work properly, even once you get it shifted upward, you need to understand you may not be able to get the full RF ower out you had in the 403-470 split, but the receiver should perk along just fine regardless, if you make the proper adjustments in teh proper way...it's all methodolgy!
The right steps in the proper order.