Galaxy 98VHP Alignment Question For The Experts

[loosecannon]

great stuff in this thread!

there was a whole curfuffle about FQP13N10's being a faulty transistor specifically because certain shops were setting them using the voltage and not the idle current.

The 13N10's got the blame so that the shop(s) could save face with their customers.
LC

 

[Mk121]

So if I was to use the spectrum analyzer to do the bias for clean output and linearity; I'm assuming adjust for lowest reading on 2nd harmonic should work? Or just look for any spurs around the fundamental? Thanks

 

[blasphemy000]

Watch the intermodulation distortion products above and below your modulation and/or fundamental as well.

 

[Unit 75]

So if I was to use the spectrum analyzer to do the bias for clean output and linearity; I'm assuming adjust for lowest reading on 2nd harmonic should work? Or just look for any spurs around the fundamental? Thanks

Do both.

 

[Handy Andy]

I must emphasize...

So if I was to use the spectrum analyzer to do the bias for clean output and linearity; I'm assuming adjust for lowest reading on 2nd harmonic should work? Or just look for any spurs around the fundamental? Thanks

Do both.

Yes! Wholeheartedly!

But not just on Bias, but for the WHOLE TX Strip.

I've seen several radios' - their power "dimmed" because they (whomever did the final tuning before packaging) wanted to just remove a "spur" or "tone" (noise) they noticed...

A radio right out of the box directly from the factory, is a good radio.

A great radio is one that has been tuned up properly by one that stands by their work and their equipment.

I've had Unidens, Galaxys, Cobras - Midlands, Tandys and just about any other radio that is out there - flow into the shop with a note that it is requiring a tune up because the "meter swings backwards" (or insert favorite complaint here) - well it does, because of issues.

One of the main ones, being what this thread is about. Bias. But that in itself is not the total fix.