SPECTRA UHF Hi POWER

[kc4iev]

SPECTRA GURU NEEDED FOR HI POWER UHF.
THE RADIO PROGRAMMED FINE AND VFO LOCKED DOWN TO 441 MHZ.
BUT THE TX OUTPUT POWER DROPS FROM 110 WATTS AT 455 MHZ DOWN TO 40 WATTS AT 446 MHZ.
I HAVE TRIED SOFTWARE ADJUSTMENTS WITH NO POWER OUT INCREASE.
ANY SUGGESTIONS???
THANKS
SCOTT

[kc7gr]

SPECTRA GURU NEEDED FOR HI POWER UHF.
THE RADIO PROGRAMMED FINE AND VFO LOCKED DOWN TO 441 MHZ.
BUT THE TX OUTPUT POWER DROPS FROM 110 WATTS AT 455 MHZ DOWN TO 40 WATTS AT 446 MHZ.
I HAVE TRIED SOFTWARE ADJUSTMENTS WITH NO POWER OUT INCREASE.
ANY SUGGESTIONS???
THANKS
SCOTT

If you band-converted a high-split radio down to amateur, the issue is that you're going below the low-end limit of the PA.

The only ways I know of to get around this is to either replace the PA altogether (ouch!), or go through the detailed service manual and change all the frequency-sensitive parts (also ouch!)

BTW, the days when computers would only recognize upper case are long gone. These days, typing in ALL CAPS is considered shouting. Just use a normal mix of upper and lower case, as if you were typing a letter, and you'll do fine.

[batdude]

in my experience....


if your spectra has a BLACK serial tag... it'll work just fine in the ham band


if it's got a WHITE serial tag.... good luck!



FYI - the black tags correspond to the AGE of the radio... the newer the radio, the higher likelihood that it will operate in the ham band




doug

[kc7gr]

in my experience....
if your spectra has a BLACK serial tag... it'll work just fine in the ham band
if it's got a WHITE serial tag.... good luck!
FYI - the black tags correspond to the AGE of the radio... the newer the radio, the higher likelihood that it will operate in the ham band

doug

Ah. That explains why the VHF radio I've got had not the slightest problem in covering 2m.

[Jim202]

Something else to consider, is the TX output filter. Haven't tried to move a UHF Spectra that far myself. I would expect it to start dropping of on the rolloff of the filter outside the design .

The Motrac and Micor radios had this issue.

Jim

[Will]

The TX filter is a low pass, should't affect the tx at 440.
First, what was the original freq range? How is the modulation at 460 and down at 445 or 441? is it still +/-5khz or does it go way off high? or Low? How is the PL or DPL modulation at the different freqs?
I may be a power control/microprocessor firmware issue. There is a way to get arround this if you want to do some surface mount soldering.

[RocketNJ]

I've changed two surface mount resistors on my Astro Spectra and was able to get the DPL and Astro deviation proper in the amateur and commercial bands. YOu need to adjust the resistors for the proper deviation/mod comp in the ham band, then align the radio. All works well.

George