As I prepare for getting on the birds.. I decided to test out this AG-25 preamp that came with my new radio. Now my experience with preamps is limited, but this one is rather baffling me.
I connected everything in line.. and powered up the preamp and at 1st glance it appeared that it worked fine, however after about 10 seconds I started questioning a few things.
#1 My noise floor went up 10db ( I've never seen this before I guess my experience with preamps is just the good ones )
#2 My Received signal quality was unchanged all it did was make the signal 'appear' stronger on the meter.
Now I know if the preamp was dead.. I would hear nothing.. so I am going to go out on a limb here and assume that its either:
a) an incredibly broad band pre-amp with a completely fictitious ' Low noise floor ' claim or
b) Detuned
I guess what Im going after is a few things with this email .. has any one ever taken one of these AG-25's and given it a proper tuning? Or is this what I should expect with this particular item?
In my previous experience (terrestrial weak sig stuff) a decent preamp may up the noise floor from a s-meter reading of mabey 0 or 1 to a s5, but with a significant increase in received signal gain. and intelligibility.
I really want to do this the correct way.. and if this thing is un-fixable junk.. its going in the junk drawer fast. I don't want to configure rx system around sompthing that wont produce results.
I'd like to thank everyone for their input so far.. Ive learned a lot w/o even Transmitting and R.F. yet!
-Steve Raas
N2JDQ