[amsat-bb] Re: V/U Linear Transponder

Tanan Rangseeprom HS1JAN hs1jan at tamsat.org
Tue Jul 30 17:24:32 PDT 2013

Dear Andrew Glasbrenner and All

We had mail to bilgi at tamsat.org.tr but do not have respond feedback. if you 
have detail e-mail or contact list of turksat team please advice to me.

best Regards

Tanan Rangseeprom HS1JAN

----- Original Message ----- 
From: "Andrew Glasbrenner" <glasbrenner at mindspring.com>
To: "Tanan Rangseeprom HS1JAN" <hs1jan at tamsat.org>
Cc: "PE1RDW" <sats at pe1rdw.demon.nl>; <g0mrf at aol.com>; <hs2jfw at gmail.com>; 
<hs5igy at hotmail.com>; <chawalit at station.in.th>; <thidad1 at gmail.com>
Sent: Wednesday, July 31, 2013 12:08 AM
Subject: Re: [amsat-bb] Re: V/U Linear Transponder

You may want to reach out to the turksat 3U team. Although the satellite has 
has problems, I believe it has redundant v/u transponders on board.

73, Drew KO4MA

Sent from my iPhone

On Jul 30, 2013, at 12:04 PM, "Tanan Rangseeprom HS1JAN" <hs1jan at tamsat.org> 

> Dear All
> Thanks respond for help to me
> 1.Thailand has regular to forbid for transmitt UHF band but can receive 
> the signal for amateur radio satellites only. we need to used VHF band 
> same like transponder  of Japanes (FO-29) , AmSat AO-51 , Saudiarabia 
> SO-50 and other satellites. for interference from China Thailand and other 
> countries on VHF is normal.
> 2.Ok, I do not have knowledge 100 khz bandwidth is too much for the over 
> power. please advice me for 30 khz uplink 145.90-145.92 MHz VHF / 435.10 - 
> 435.12 MHz UHF of  liner transponder.
> 3.We have to design FM repeater use to modify HX1 / RX2A RADIOMETRIX VHF / 
> UHF transmitter module we have change x-tal to 145.90 MHz / 13.59 MHz and 
> used MC3361 with x-tal 10.245 MHz and CML IC FX465 CTCSS Encode/Decode 
> build test it to be successful.
> We and technical team of TAMSAT group would like to help and advice for 
> circuit diagram of V/U transponder same like transponder of Japanes 
> (FO-29) and other satellites. We had mail to Mr.William Leijenaar PE1RAH 
> but do not have respond feedback. Mrs Thida of 100watts ham radio magazine 
> of thailand sugges me to know Mr.William.because she meet him on Tokyo ham 
> fair 2009.
> On this time we and technical team of TAMSAT group need help very urgent. 
> we need advice of circuit diagram or datasheet  IC for build V/U Liner 
> transponder  for payload 1U cubesat of JAISAT satellite project.
> best regards
> Tanan Rangseeprom HS1JAN
> Project Manager of JAISAT-1
> member of RAST
> email : hs1jan at tamsat.org
> ----- Original Message ----- From: <g0mrf at aol.com>
> To: <hs1jan at tamsat.org>
> Sent: Monday, July 29, 2013 5:24 PM
> Subject: Re: [amsat-bb] V/U Linear Transponder
> Dear Tanan.
> Thanks for the mail via AMSAT.org
> My name is David Bowman  G0MRF and I'm a member of the team building
> FUNcube, due for launch this November.
> I can help with transponder design, but there are some points which you
> need to consider.
> 1) The use of V band for the uplink will be a poor choice for your
> location.  The interference from China and other countries on 145MHz
> will mean the transponder will not be usable.   Using U band for the
> uplink is a much better choice.
> 2) The 100kHz bandwidth is too much for the typical power available
> from a CubeSat. If you get your RF team to do a link budget analysis,
> you will see the cubesat power budget will not support 100kHz of
> bandwidth. Ususally 30kHz is as much as you can do with a 1U cube.
> 3) You may want to consider a FM 'repeater' as there is now only 1 in
> orbit, while there are several linear transponder satellites ready to
> be launched.
> The FM design will allow you to run a very efficient power amplifier
> (70%) and power can be saved over oceans and areas of low population by
> using a 67Hz access tone (CML FX465)
> I can assist with design but would need to know if you are planning a
> 1U 2U or 3U design.
> William PE???? is good, but will probably just offer to sell you a
> transponder.
> Regards
> David  G0MRF
> some old info is available at   www.g0mrf.com/transponder.htm
> The attached powerpoint has some pictures of the UV transponder and
> other boards in FUNcube from AMSAT-UK
> _______________________________________________
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