[TenTec] InRAD 2.1 kHz Filter for the Argonaut 509 (The Argo from Hell)

[M. P. Haynes]

Rich,

Sounds like you might make it in time for Straight Key Night!

Pat-K4BEH

On Tue, 21 Dec 2004 21:46:51 -0500 "Richard Arland"
<richard.arland at verizon.net> writes:
> 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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