The stuck PTT while running SSTV on ISS has been a known issue since the vox box was first connected to the TM-D700 in the year 2005. The ISS crew soon discovered the stuck VOX transmitter issue.
One ISS crewmember left the radio running all night sending SSTV images. The next morning the radio was excessively hot and would not respond to button commands until after the radio was “power cycled”.
The Ariss vox box does not have any RF filtering inside the device. The devices was originally designed to run on its own 9-Volt battery. At the last minute, it was modified to extract power from the TM-D700. The Ariss vox box gets its power from the D700 via a special modification to the D700 transceiver.
The unfiltered power is full of RF energy when the D700 starts transmitting.
The RF energy causes the VOX PTT circuit to get stuck in a transmitting mode until the Watch dog timer in the D700 times-out and forces the radio back to receiving mode.
Marexmg, the organization that supplied the Marex SpaceCam1 SSTV software for ISS has recommended to ARISS several times to replace the ARISS vox box with a stable USB vox box. ARISS has repeatedly ignored any attempt to correct the problem. Sincerely Miles WF1F Marex http://www.marexmg.org/fileshtml/futureprojects.html
________________________________ From: Fabiano Moser fabianomoser@gmail.com To: amsat-bb amsat-bb@amsat.org Sent: Thursday, September 5, 2013 6:57 AM Subject: [amsat-bb] Re: R: Re: ISS SSTV Active on 145.800Mhz
Hi,
SSTV active with problems, PTT was activated but no audio, then after 20seconds± the audio started and goes out before the end of image. PTT still ON without audio till LOS.
On Thu, Sep 5, 2013 at 10:22 AM, Claudio Ariotti, IK1SLD < claudio@ariotti.com> wrote:
Hi Jan, about your comment I read on your web, the Luca Parmitano don't use the Kenwood TM-D710, this radio is used by Russian crew. The MAI-75 Experiment is a Russian experiment and the crew activates it when Moscow has AOS, so we lost 50% of the pass. Luca only use the Ericsson radio in the Columbus module.
73 Claudio IK1SLD
-----Messaggio originale----- Da: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] Per conto di PE0SAT | Amateur Radio Inviato: giovedì 5 settembre 2013 10:35 A: amsat-bb@amsat.org Oggetto: [amsat-bb] Re: ISS SSTV Active on 145.800Mhz
Hi Cor,
Via this link: http://www.pe0sat.vgnet.nl/2013/iss-sstv-reception/ you can download the SSTV images I received yesterday.
73 Jan PE0SAT
On 04-09-2013 20:47, Cor . wrote:
Hello All,
Several ISS SSTV images are received from several ground stations. See ISS SSTV images and info: http://ariss-sstv.blogspot.nl/ http://www.dk3wn.info/satblog.shtml
I asume the Russian ISS crew have sended 4 different SSTV images today. If someone have received other images please send them to me via e-mail (see my QRZ.com page).
Tommorow Sept. 5 between 09:00 and 10:40 UTC last day of the event.
73's Cor PD0RKC
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-- With regards PE0SAT Internet web-page http://www.pe0sat.vgnet.nl/ _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb