[amsat-bb] Re: AO40 contacts

i8cvs domenico.i8cvs at tin.it
Sat Feb 5 15:08:30 PST 2011

Hi Matthias, DD1US

The experiment to transmit to AO40 using a 2400 MHz uplink and a 24 GHz
downlink i.e the mode S1/K was made only ONE TIME and never was repeated
and it was skeduled by command station W4SM to check if the onboard 2400 MHz
S1 receiver was working or not.

There are many other 24 GHz downlink QSO's but they where all made using
the  1.2 GHz uplink i.e. using the mode L/K

Charlie G3WDG has the record of the above unique S1/K test and you can get
a copy from him.

By the way if I will be able to find the above WAV file in my PC I will send
it to you for your record.

I actually have on hand only the CD diskette of my signal on 24 GHz for the
above S1/K test as received in USA by Mike N1JEZ

Here is copy of the original text of the message sent by W4SM on AMSAT-BB
on day february 23 2003 after the succesfull experiment.

Two tests were performed on AO-40 today.

The first was a long shot and involved listening for the S1 transmitter
exciter stage using Günter Wertich's EME dish.  Nothing was heard during a
20 MA window of testing in which the S1 Tx was connected to the middle

The second test involving the S-band receivers was completely
successful.  Extremely strong downlink signals were possible using S-band
uplink to K-band downlink.   Charlie (G3WDG) phoned me and I heard
beautiful downlink signals from his ~5 watt uplink to S1.  S2 was also
active, but because of its higher, less common frequency (2446 MHz), it may
not have been tested.  The S1 Rx uses the S1 Tx high-gain dish, and the S2
Rx uses the 5 turn helix used by the S2 Tx, so signals would not be as
strong through S2 at low squint.  More information will undoubtedly be
posted on this by the participants, but special thanks to Charlie (G3WDG),
Mike (N1JEZ),  and Dom (I8CVS), and any others who participated in this
successful test.

The S1 Rx can certainly be listed as fully functional.  We will await
further testing/info. on the S2 Rx.

W4SM for the AO-40 Command Team

73" de

i8CVS Domenico

----- Original Message -----
From: "Matthias Bopp" <matthias.bopp at gmx.de>
To: <amsat-bb at amsat.org>
Cc: "'i8cvs'" <domenico.i8cvs at tin.it>
Sent: Saturday, February 05, 2011 8:12 PM
Subject: AW: [amsat-bb] Re: AO40 contacts

Hi Domenico,

I do not think that this has been the only 24 GHz experiment on AO-40.
You can find audio recordings of the 24 GHz signals of DK1KQ and DB6NT on my
website www.dd1us.de in the sounds from space collection. I will be happy to
add your signals too if you want to provide me a copy of the recording.

Best regards

Matthias DD1US


-----Ursprüngliche Nachricht-----
Von: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] Im
Auftrag von i8cvs
Gesendet: Samstag, 5. Februar 2011 18:33
An: n1jez at burlingtontelecom.net; amsat-bb
Betreff: [amsat-bb] Re: AO40 contacts

----- Original Message -----
From: <n1jez at burlingtontelecom.net>
To: "amsat-bb" <amsat-bb at amsat.org>
Sent: Friday, February 04, 2011 1:16 PM
Subject: [amsat-bb] Re: AO40 contacts

> Those were fun days Clare!
> My most challenging contacts were made using K band (24 GHz down). First
> contact was on 4/20/2002 with Jerry, K5OE.
> http://www.burlingtontelecom.net/~n1jez@burlingtontelecom.net/index.html
> I think the only mode I never got to try was 2.4 GHz up. I have the
> transverter sitting here in my shack, but AO-40 went bang before I got to
> use it. The plan was S/k.
> 73,
> Mike, N1JEZ
> AMSAT 29649
> "A closed mouth gathers no feet"
Hi Mike, N1JEZ

You should remember that you and I and Charles G3WDG we partecipated
to the only one test made on 2.4 GHz up and 24 GHz down i.e. mode S1/K
on AO40 on day 02/23/2003 and I was received on 24 GHz both by you and
by G3WDG.

I still have your CD diskette made by you and sent to me with the record of
my 24 GHz signal received by you in Burlington VT

Unfortunately at that time I was not ready to receive on 24 GHz but I was
only able to transmit on 2.4 GHz with 10 watt at a 4 feet prime focus dish.

Unfortunately for that experiment scheduled by AMSAT and command
station Stacey Mills W4SM only three stations where active i.e  G3WDG,
N1JEZ and my self ,i8CVS

G3DWG was equipped to transmit on 2.4 GHz and to receive on 24 GHz
so that only he was able to get back his own signal from the transponder.

You where only able to receive on 24 GHz but not to transmit on 2.4 GHz
so that you where able only to copy G3WDG and i8CVS on 24 GHz

I was able only to transmit on 2.4 GHz but not to receive on 24 GHz so
that at the end of the experiment no  two way QSO S1/K was possible
to made between us but most important the experiment demonstrated
that the S1 2.4 GHz receiver on board of AO40 was working and was
alive and well !

Those were really fun days Mike !

73" de

i8CVS Domenico

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