Batboard

On board have 5 screw near PA board.I thing it is band pass fillter.Can I adjust it for high senstivity?

taksin25 wrote:On board have 5 screw near PA board.I thing it is band pass fillter.Can I adjust it for high senstivity?

What bandsplit is the radio, and how far outside that bandsplit are you trying to go?

In any case: You are partly correct. There are three slugs for the injection filter, and five more for the preselector.

HOWEVER -- Proper adjustment of these slugs, since you are dealing with a bandpass filter, absolutely requires a spectrum analyzer and tracking generator combo, and the skill to use them correctly. What you would be doing is altering the passband -- sacrificing performance at one end of the band to gain it at the other. The filters are about 22-23MHz wide.

This is a conversion I've done several times, in the interests of getting both VHF and UHF X9000's into the amateur bands. Both are tricky, and the UHF units do not always cooperate if they do not have a receiver preamp. Simply tweaking the screws with a non-swept signal might work in the short term, but you will cause yourself all kinds of headaches down the road, especially if you're trying to cover an entire amateur band, or monitor commercial frequencies along with amateur.

Hope that helps.

Only if you have access to a tracking spectrum analyzer and a lot of free time. Otherwise, don't touch.