Gang:
Steve Wilson, XE1UFO, graciously provided what I thought was supposed to be an
Argo 505 (his first rig) as a parts rig for me to cannabalize to get "The 509
From Hell" back on the air. It arrived today. Boy! Was I surprised when I
opened Steve's box and found not a 505 but a 509 instead! Granted it was in
pretty rough cosmetic shape, but it was a 509 and that means I can swap some
boards out in an attempt to get "The 509 >From Hell" to work on 10M.
For those of you who have forgotten (or have tried to forget) the last
installment, I have managed to swap out all the transistors on the OSC board
with 2N2222As in metal cans. Garland Jenkins from the T-T Lab graciously
provided a new 10M coil and a T-1 transformer (doubler/tripler) coil along with
several of the orange plastic dial pointers that were damaged in the original
order during shipping. Thank you, Garland!
I substituted the coils and got the doubler/tripler to work as it should, but
the rig still won't take off and oscillate on 10M, indicating that the switch
wafers are either badly damaged or not making proper contact. Thanks to Steve's
generousity I now have the ability to swap out the entire oscillator PCB from
Steve's old rig, OR I can remove the switch wafers from Steve's old rig and put
them into mine. Either way I end up with a way to check out the final stumbling
block in getting "The 509 From Hell" to work on 10M.
More on this as soon as I can catch my breath and get a chance to pop open
Steve's old rig and pull the OSC board. God willing, I might have a 100%
functional 509 by the first of the New Year.
Now....for the real reason I started this posting................
Has anyone out there ever used an International Radio (InRAD) model 752 xtal
filter in an Argo 509? This xtal filter is made for an IF Freq of 9001.5 kHz.
It is a 2.1 kHz wide, 8 pole xtal filter on a small PCB. There are four (4)
pins on the PCB. I have no other information or installation instructions. My
Argo's IF filter is the stock 4 pole, 2.8 kHz 9Meg filter comprised of four (4)
individual xtals soldered into the SSB Gen board (P/N 80131). On all the
previous 509s I done the IF filter swap on, they have all had the four xtals
mounted on a small PCB that sat piggy back on the top of the SSB Gen board.
HELP!!!! I need some info as to how to correctly (the operative word, here)
make the swap and will I need to realign the IF or SSB Gen boards once I do the
swap?
I am anxiious to do this mod with this particular xtal filter as it should
really make an improvement in the Argo's receive specs. Speaking of which, has
anyone ever tried using a wide band noise source and a program called
Spectragram to map out the stock filter? The usual "mod" entailed swpping the 4
pole stock filter with a T-T 8 pole 2.4 Khz xtal filter. I would be interested
in finding out the quantitative difference in doing this mode. Has anyone tried
this todate?
73 and thanks for allowing me to utilize all the bandwidth
Merry Christmas
Rich K7SZ
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