April 2013 - AMSAT-BB - mailman.amsat.org

Re: Mount an Arrow on rotator with 2m vertical or horizontal
by Gus 16 Apr '13

16 Apr '13

No reason why not. The power at each antenna will be 3 dB down, but you will get an additional 3 dB of gain for using two antennas, so there will be (nominally) no loss, assuming the antennas are oriented the same. Or you could orient them 90 degrees apart, use an electrical 1/4 wave matching section of 75 ohm coax on each antenna, plus an electrical 1/4 wave phasing section of 50 ohm coax on ONE antenna, and you have CP radiation. Use a double-throw relay to switch the phasing section from one antenna to the next, and you have switchable RHCP/LHCP. In this case you WILL suffer a 3 dB penalty when working signals with linear polarization. Another possibility I want to try some day: use a radio with diversity reception (like IC-2820). Connect one horizontal antenna and one vertical. No matching or phasing, no manual switching of circularity. Just let the receiver decide which antenna is pulling in the strongest signal on a moment by moment basis. Tx polarity is fixed, but you can turn up the wick to compensate! On 04/16/2013 02:31 PM, Douglas Phelps wrote: > Any reason why, using identical coax lengths, you could not transform the > impedance to 100 ohms and then use a T connector to sum both antenna signals and > achieve 50 ohms to the radio? I know Transmit power will be 3 dB down at either > antenna but is there any reason it will not work? Any antenna gurus out there? > > > > > ________________________________ > From: R.T.Liddy <k8bl(a)ameritech.net> > To: amsat-bb(a)amsat.org > Sent: Tue, April 16, 2013 11:46:35 AM > Subject: [amsat-bb] Re: Mount an Arrow on rotator with 2m vertical or horizontal > > For the Satellites, it completely doesn't matter. At any given moment, > you only have 1 chance in 90 that you will have matching polarization. > > So, if you plan to use the antenna for other than Satellites, set your > polarization > for that purpose (V for FM or H for SSB/CW). > > My plan is to install 2 Elk antennas, one V and one H. Then, have a relay that > I can switch between the two and choose the best downlink signal at any > given moment. This arrangement will also give me optimum flexibility for > terrestrial operation on 2 & 440. > > Now, where can I find a relay to do that function????? > > 73/GL, Bob K8BL > > > --- On Tue, 4/16/13, Lee Maisel <maisel(a)lobo.net> wrote: > > > From: Lee Maisel <maisel(a)lobo.net> > Subject: [amsat-bb] Re: Mount an Arrow on rotator with 2m vertical or horizontal > To: "Don Hoover (WS4E)" <ws4e(a)arrl.net> > Cc: amsat-bb(a)amsat.org > Date: Tuesday, April 16, 2013, 12:24 AM > > > Hi Don, > > I have mine mounted with 2m elements horizontal, because that's how it > seems I used it most when it was handheld. > > Lee > W5LMM > > > Don Hoover (WS4E) wrote: >> Just wondering, should I mount my arrow with the 2m elements oriented >> vertical or horizontal? >> >> I am planning on putting it at 15deg and just using a az rotator. >> >> Does it even matter which way its oriented since the polarity of the sats >> are always changing? >> >> Maybe I should mount it like this: / instead. >> >> Just curious what some thought was the best way to go. >> _______________________________________________ >> Sent via AMSAT-BB(a)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 >> >> > -- 73, de Gus 8P6SM Barbados, the easternmost isle.

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Re: Half-duplex on the Kenwood TH-F6A
by Andrew Glasbrenner 16 Apr '13

16 Apr '13

Nah, no worries! It's a fun mode, but can be a challenge tuning to keep up by hand. 73, Drew KO4MA -----Original Message----- >From: Zach Leffke <zleffke(a)vt.edu> >Sent: Apr 16, 2013 5:26 PM >To: 'Andrew Glasbrenner' <glasbrenner(a)mindspring.com>, amsat-bb(a)wd9ewk.net, amsat-bb(a)amsat.org >Subject: RE: [amsat-bb] Re: Half-duplex on the Kenwood TH-F6A > >Ahhh, my apologies Drew. I should have said previously uncommon modes instead of unheard of modes. As I am relatively new to the Amateur Satellite community, I'm sure there is plenty that I am unaware of, and this is an example of that. Again, my apologies. I'm looking forward to seeing how things play out in the future. > >-Zach, KJ4QLP > >-----Original Message----- >From: Andrew Glasbrenner [mailto:[email protected]] >Sent: Tuesday, April 16, 2013 5:11 PM >To: Zach Leffke; amsat-bb(a)wd9ewk.net; amsat-bb(a)amsat.org >Subject: Re: [amsat-bb] Re: Half-duplex on the Kenwood TH-F6A > > > > >-----Original Message----- >>From: Zach Leffke <zleffke(a)vt.edu> >> This technology will allow previously unheard of modes of operation >>that could allow these types of HTs to complete a QSO. Imagine a >>software defined transponder that receives an uplink in FM and >>downlinks SSB. > >I did that on AO-16 after we put it in "bent pipe" mode, although that was FM to DSB. The ISIS cubesat radios also have this ability, and I think we'll see it on some of those soon. > >73, Drew KO4MA > > >

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Re: Half-duplex on the Kenwood TH-F6A
by Andrew Glasbrenner 16 Apr '13

16 Apr '13

-----Original Message----- >From: Zach Leffke <zleffke(a)vt.edu> > This technology will allow previously unheard of modes of >operation that could allow these types of HTs to complete a QSO. Imagine a >software defined transponder that receives an uplink in FM and downlinks >SSB. I did that on AO-16 after we put it in "bent pipe" mode, although that was FM to DSB. The ISIS cubesat radios also have this ability, and I think we'll see it on some of those soon. 73, Drew KO4MA

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Half-duplex on the Kenwood TH-F6A
by Robert Kovacs 16 Apr '13

16 Apr '13

Someone earlier was asking about the TH-F6A. As mater of terminology, is it called "half-duplex" or "cross-band split"? The Kenwood TH-F6A has two receivers but will not work full duplex; you cannot hear your own signal coming back down from the satellite. What I do is use dual mode, so that both A & B are on, with the uplink on one and the downlink on the other. Set the audio fully on the downlink (because you don't want to listen to the uplink frequency) but leave the active or primary on the uplink side. That way, you can hear the bird, and when you key the PTT hopefully you can hit the bird. With an HT! My experiences though are with the FM easysats (including AO-51 of happy memory). Has anyone had any luck with this radio's SSB receivers for the linear birds? 73, Bob Kovacs. KC2WYH Amsat No. 38304.

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ALL AMSAT rooms at Hamvention 2013 taken
by Alan 16 Apr '13

16 Apr '13

All, Per Martha at the AMSAT Office, the entire block of AMSAT rooms for Hamvention 2013 are now taken, and no more will be available. 73s, Alan WA4SCA

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Re: Mount an Arrow on rotator with 2m vertical or horizontal
by Richard Lawn 16 Apr '13

16 Apr '13

I have both the Arrow and the Elk and am interested in trying them mounted at a fixed elevation and would love to see pictures or diagrams/explanations of how you have mounted the Arrow. The Elk is easy and Ive got parts and info on how to mount it for rotor use. TNX Rick W2JAZ

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For Sale :
by Bruce R Brown 16 Apr '13

16 Apr '13

ST-1 Fox Delta tracker..factory assembled...factory case. $55 shipped to your door. ST-2 Fox Delta tracker...factory assembled..factory case. $135 shiped to your door. Pay pal preferred..tks es 73 Bruce ke0lx willmarbrowns(a)charter.net

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Time Is Running Out
by Martha 16 Apr '13

16 Apr '13

If you are planning to stay with the AMSAT group in Dayton, you need to call me before 4/24. At that time, we lose the block. I will need your room nights and a credit card to hold the room. Time is running out - make that call! (301-589-6062) -- 73- Martha

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CSUN CubeSat project gets $25,000 from JPL
by M5AKA 16 Apr '13

16 Apr '13

Professor Sharlene Katz, WB6FFE and Professor James Flynn, WB9AWX have received $25,000 from the Jet Propulsion Laboratory for a CubeSat project, see http://amsat-uk.org/2013/04/16/radio-amateurs-get-25000-for-cubesat/ Also on the AMSAT-UK site: Video – The CanSat Leader Training Program http://amsat-uk.org/2013/04/15/cansat-leader-training-program/ ---- Trevor M5AKA AMSAT-UK http://www.amsat-uk.org/ Join or Renew your AMSAT-UK membership at http://shop.amsat.org.uk/shop/category_7/Membership-of-AMSAT-UK.html ----

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Mount an Arrow on rotator with 2m vertical or horizontal
by Don Hoover (WS4E) 15 Apr '13

15 Apr '13

Just wondering, should I mount my arrow with the 2m elements oriented vertical or horizontal? I am planning on putting it at 15deg and just using a az rotator. Does it even matter which way its oriented since the polarity of the sats are always changing? Maybe I should mount it like this: / instead. Just curious what some thought was the best way to go.

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