[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: RE: S band for 6 bucks



This is excellent news Woody! Could you explain in more detail how you went 
about tuning up the filter?

73, Drew KO4MA

PS...Who bought the rest of those from Ebay...none to be found today!

----- Original Message ----- 
From: "Woody" <kj4so@nc.rr.com>
To: <amsat-bb@AMSAT.ORG>
Sent: Monday, June 13, 2005 5:07 PM
Subject: [amsat-bb] RE: S band for 6 bucks


> Hi All:
>
> I replaced the crystal in the Cal Amp 13215 downconverter today and all 
> went very well.  Observing the LO output on a spectrum analyzer, the 
> signal is strong, clean, & stable.  The crystal was manufactured by JAN 
> and is slightly low in freq.  The LO is 2.25588 MHz. instead of 2.256 MHz. 
> I prefer "International Crystal" crystals, but I already had the JAN 
> crystal.
>
> With an input level of -70 dB, the 144 MHz. IF output level is -38 dB. 
> This is the same level that the unmodified Cal Amp 130215 downconverter 
> shows with an input of 2.5 GHz.
>
> I retuned the combline input filter and touched up the LO reference 
> crystal's trimmer capacitor to get the LO as close as possible to 2.256 
> GHz.  I have not made, nor do I plan to make any other adjustments or 
> modifications to the downconverter.
>
> I have modified several Drake, AIDC, and other models of Cal Amp 
> downconverters.  This downconverter is the simplest one that I have 
> modified so far.
>
> The seven-pole combline filter on the input is very impressive. Properly
> tuned, it should really help to keep unwanted signals out of the 
> downconverter's input.
>
> Thanks again, Drew for the "heads up" on the $6 S-band downconverters.
>
> 73,
>
> Woody
> KJ4SO
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home