[amsat-bb] Re: mode s converter
Andrew T. Flowers, K0SM
aflowers at frontiernet.net
Sun Jan 20 16:42:42 PST 2008
I've been able to use a FT-470 transmitting somewhere in the 440 band to
generate signals test signals all the way through 10 GHZ. It helps to
have an IF radio that can be set in WBFM for this, since that is what
your NBFM signal becomes on those harmonics. You can always verify that
you are listening to the harmonic and not some image by changing the
frequency on the transmitter by 5kHz, as that should be multiplied
appropriately on the IF.
Bruce Robertson wrote:
> It's been a while since I've had my s-band equipment working, but as I
> remember, an access point makes what appears to be an increase in the
> noise level on a SSB/CW radio. (My linksys wifi router provides the
> same service on all bands!) The nice thing about a signal generator is
> that you have a single tone that you can hear with certainty, take
> s-meter readings of, etc. When I had my downconverter and patch
> antenna on my mast, I used to turn on the signal generator and point
> the array at my shack, where I was holding the signal generator, as a
> way of ensuring that everything was working.
> Diane points out that calculating the frequency can be difficult. This
> is true, but if you have an all-band radio, you can listen to the
> harmonic of a 40 MHz can which should be up around 440 MHz. The error
> will be multiplied 11 times, and you can use that to get a pretty good
> idea of where the signal generator should appear in the s-band.
> 73, Bruce
> On Jan 20, 2008 4:24 PM, Stefano Simonetti <iw1rdz at yahoo.it> wrote:
>> Thanks for the answers,
>> I have here a 50MHz block, I will try, thank you, I already saw those
>> projects at the ao40 days...Now finally I will make the circuit.
>> I was also wondering if a wifi access point beacon would do the work.
>> ISM band starts at 2400 and channel 1 is from 2401 to 2423 with the center
>> of 2412.
>> I tried but heard nothing, I don't know if there should be RF around
>> 2401-2402 from an access point beacon tuned on channel 1.
>> What do you think about?
>> 73 - Steve - IW1RDZ
>> ----- Messaggio originale -----
>> Da: Diane Bruce <db at db.net>
>> A: Bruce Robertson <ve9qrp at gmail.com>
>> Cc: Stefano Simonetti <iw1rdz at yahoo.it>; AMSAT BB <amsat-bb at amsat.org>
>> Inviato: Domenica 20 gennaio 2008, 20:29:32
>> Oggetto: Re: [amsat-bb] Re: mode s converter
>> On Sun, Jan 20, 2008 at 02:03:57PM -0400, Bruce Robertson wrote:
>>> On Jan 20, 2008 12:44 PM, Stefano Simonetti <iw1rdz at yahoo.it> wrote:
>>>> Hi to all, I would like to test my "old" AO40 13cm converter
>> (2400-2402MHz) to see if it is still alive...
>>> If you need a cheap-and-dirty signal source, try using one of those
>>> small, canned RF oscillators at 40 MHz. Properly powered with a 5v
>>> voltage regulator and a 9v battery, it will produce a harmonic signal
>>> that you'll hear well from right next to the downconverter, and, with
>> It works a treat. There is a design using a filter
>> here: http://www.g4dmf.co.uk/2400/2400.html I've not gotten around
>> to building it.
>>> a gain antenna, from some distance away. Don't worry about building it
>>> an antenna. If you're not sure if what you're hearing is the sig gen.
>>> or a birdie, just blow on the sig gen, and its frequency will warp!
>> The problem with the xtal module is which harmonic are you listening to?
>> It's good enough for tweaking your converter and making sure things work,
>> but it's not going to reliable to use as a frequency standard. ;-)
>>> At $2, it was all I used to hack and tweak my downconverter. I got
>>> this idea from a VE2 ham's webpages, but I can't seem to google them
>>> up right now.
>> I took one off an old 386sx board; Just about any old
>> xtal module will multiply up into 2.4.
>> - 73 Diane VA3DB
>> - db at FreeBSD.org db at db.net http://www.db.net/~db
>> L'email della prossima generazione? Puoi averla con la Nuova Yahoo! Mail
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