March 2008 - AMSAT-BB - mailman.amsat.org

2401/144 down conveter and antenna questions
by CLAUDIA PIRKL 01 Apr '08

01 Apr '08

Hello all. I found a 2401/144 down converter on the internet but when it came in the mail there was no info with it. It is a TranSystem Model AIDC-3733 and I think it came from K5GNA. I removed one cover (antenna on left/144 IF facing me) and found a wire with one end not connected. I realize it needs some DC volts to operate but how much and where it needs to be brought in. Does any one have any info to help me out? On the internet there a few helix antenna designs for 2401. I found a piece of 1" PVC and some AL. ground wire. I wrapped the wire around the PVC and came up with the 4cm dia. the article talked about. But, in another article (435 Mhz) it was mentioned the PVC was very lossy. What do you think?? Thanks for any help!! Tim N5KI EM65

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RHC or LHC?
by w0dxz＠aol.com 31 Mar '08

31 Mar '08

I have this old CCraft? 432 beam i want to try,? it is wired for LHC,,, I can rewire it for RHC... which would be better, R or L?? I wont be able switch between the two.?? (for now) If I can only use? one, R or L, would that still be better than a standard 2M beam turned at 45 degrees? Bob W0DXZ

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Re: Question about Frequencies to use on VO-52
by George Henry 31 Mar '08

31 Mar '08

-----Original Message----- >From: Ronald Nutter <rnutter(a)networkref.com> >Sent: Mar 31, 2008 11:47 AM >To: amsat-bb(a)amsat.org >Subject: [amsat-bb] Question about Frequencies to use on VO-52 > >I am trying to learn how to use the SSB birds. What are the "starting" >frequencies that most use for uplink and downlink ? If I understand >this correctly, you will leave the uplink set and then only tweak the >downlink ? > >Thanks, > >Ron >KA4KYI The convention on the linear birds is that the lower half of the downlink passband is for CW, and the upper half is SSB. So, you should pick an uplink frequency that will place your downlink in the appropriate half of the passband, and then adjust the higher of the two for doppler. In the case of VO-52, that means picking a frequency in the LOWER half (435.2200 - 435.2500) of the uplink passband in order to appear in the UPPER half (145.9000 - 145.9300) of the downlink passband (VO-52 uses an inverting transponder), and adjust only your uplink to keep your downlink frequency constant. And it's LSB on the uplink to give USB on the downlink. The ideal situation, if you have a radio that is CAT ready, is to use something like SatPC32 that will adjust BOTH your uplink and downlink for doppler, as well as automatically setting the uplink frequency that corresponds to your chosen downlink. Enjoy! VO-52 is an awesome satellite! George, KA3HSW

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Re: AMSAT-BB Digest, Vol 3, Issue 161
by Mark L. Hammond 31 Mar '08

31 Mar '08

Hi Alan, For your KEPS downconverter---you can power it through the coax! That's the slickest way to power that fine peice of hardware without any muss or fuss. I lashed up a homebrew coax injector that has Anderson power pole connectors on it. Works like a champ. 73, Mark N8MH _______________________________________________ Date: Mon, 31 Mar 2008 14:03:10 -0500 From: "Alan" <ve4yz(a)mts.net> Subject: [amsat-bb] Re: ARR pre amp Query To: "'Bill Dzurilla'" <billdz.geo(a)yahoo.com>, <amsat-bb(a)amsat.org> Message-ID: <000f01c89361$dcea1be0$0602a8c0@athlon> Content-Type: text/plain; charset="us-ascii" Very timely discussion for me as the snow sloooowwly disappears and the return of the Canada geese and robins signals the time for tower work :-) Some previous comments suggest that a preamp near the rig is not significant, but, I suggest otherwise as my Ft-847 internal preamps can make a significant difference in RX. Anecdotal, not empirical, but I can hear the diff at the push of a button. Now, I am consider mast mounted preamps as an alternative to my FT-847 internal preamps for one of my sites. I run Landwehr VHF and UHF preamps at 2 other locations and they are terrific! They are also almost 20 years old and no longer available :-( The preamps on the AR2 site look like what I could use. My questions are... Is the sequencer http://www.advancedreceiver.com/page20.html really necessary or recommended when using the MSP432VD-25 or MSP144VDG-25 preamps? My first thought is NO. 15-20 years of use of 4 Landwehr preamps without a sequencer is my rational. Finally, does anyone have a nice "warranty voiding" hack to get around the these different power connectors we see on indoor preamps and down converters such as my KEPS http://www.keps.it/images/13lnc72db_m.jpg ? Instead of soldering to the pin and a ground lug http://picasaweb.google.com/ve4yz.alan/24Ghz/photo#5172119570416133618 Something as simple as removing the connector from the case and running a cable through the remaining hole, soldered internally with something like Anderson Power Poles at the other end for 12VDC????? I'm going to do it one day, but would rather have someone else confirm that it would work without adversely effecting performance characteristics. No guts; no glory here. Thanks for any feedback 73, Alan VE4YZ EN19kw AMSAT LM 2352 http://www.mts.net/~ve4wsc/ AMSAT A-485 -- Mark L. Hammond [N8MH]

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Re: ARR pre amp Query
by Bill Dzurilla 31 Mar '08

31 Mar '08

The more expensive "mast mounted" versions (MSP432VDG-160, $240 and MSP432VDG-25, $190) come with a power connector, but the RF switched SP432VDG, $120 (25w rating) does not. You have to solder or clip the wire for the +13vdc to the top of a feedthrough, and the wire for the -13vdc to a solder lug attached to a screw on the chassis. Yes, a bit crude. See http://www.advancedreceiver.com/page37.html By the way, the "RF switched" preamps come standard with BNC connectors. You can buy them with N connectors for an extra $10, but they will not sell them with UHF connectors (SO-239). The "mast mounted" versions come standard with N connectors. 73, Bill NZ5N >>Hi Bob, The Advanced Receiver pre-amp that I purchased (MSP432VDG-160) came with the power connector. You will need to solder the wires to the connector. I found some old RG-58 that I used to run the power to it. Very nice pre-amp by the way. 73, Jeff K7WIN ----- Original Message ----- From: <w0dxz(a)aol.com> To: <amsat-bb(a)amsat.org> Sent: Monday, March 31, 2008 8:04 AM Subject: [amsat-bb] ARR pre amp Query >I am thinking aobut ordering an ARR pre amp for 432,,, I see the pin for >12V DC,,, what type of connector does this take, or do you have to solder >the? wire to the pin? That seems a bit crude. > Canby one use the ARR product, and how do you connect the 12V to it? ____________________________________________________________________________________ No Cost - Get a month of Blockbuster Total Access now. Sweet deal for Yahoo! users and friends. http://tc.deals.yahoo.com/tc/blockbuster/text1.com

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Re: Preamp for a Mobile Application
by John W Lee 31 Mar '08

31 Mar '08

Guys, Well, Those SP432VDG's work REAL GOOD for mobile operation. My mobile has a quarter wave whip (6.5 inches long) for receiving on UHF. Those low-noise preamps DO help a lot. And if you like to use a small beam to receive with, then the preamp will help that, too. I mean you get a LOUD signal that you can actually copy thru the whole pass instead of "in and out" and lots of "no copy" time. And of course the noise level is still zero or near it. This is not just an opinion, this is tried and true. I have logged thousands of contacts on the FM birds while mobile and portable with pretty minimal rigs. 73, John K6YK On Mon, 31 Mar 2008 07:01:03 -0700 (PDT) Bill Dzurilla <billdz.geo(a)yahoo.com> writes: > Kent, > > Never tried it, but I doubt a preamp would be worth > the expense if mounted at the rig in a mobil set-up. > I assume the feedline is only 10' or so. The preamp > helps most when the feedline is lengthy, especially if > cheap coax is used. > > If you want to try a switching preamp, the ARR > SP432VDG is a good one, see > http://www.advancedreceiver.com/page7.html > > For about the same price, you could buy an Arrow > handheld yagi antenna, which would substantially > improve both reception and transmission. See > http://www.arrowantennas.com/146-437.html , although > if the rig is fixed inside your car if might not be > convenient to hold the Arrow, unless your mike cord is > long enough so you can stand outside the car. > > If you are limited to operating from the car, try > driving to a hilltop or somewhere with a clear view > from horizon to horizon. > > 73, Bill NZ5N > > > > _________________________________________________________________________ ___________ > Like movies? Here's a limited-time offer: Blockbuster Total Access > for one month at no cost. > http://tc.deals.yahoo.com/tc/blockbuster/text4.com > _______________________________________________ > 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 > >

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ARR pre amp Query
by w0dxz＠aol.com 31 Mar '08

31 Mar '08

I am thinking aobut ordering an ARR pre amp for 432,,, I see the pin for 12V DC,,, what type of connector does this take, or do you have to solder the? wire to the pin? That seems a bit crude. Canby one use the ARR product, and how do you connect the 12V to it? Bob W0DXZ

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Re: ARR pre amp Query
by John W Lee 31 Mar '08

31 Mar '08

Bob, There's a ground lug and small pin on the preamp. I put a female pin on the wire for the 12 volt connection and soldered on the ground. I have 2 of those and they work great. Even run them from a HT battery when operating portable, maybe 9.6 volts or so, works fine. 73 John K6YK On Mon, 31 Mar 2008 11:04:00 -0400 w0dxz(a)aol.com writes: > I am thinking aobut ordering an ARR pre amp for 432,,, I see the pin > for 12V DC,,, what type of connector does this take, or do you have > to solder the? wire to the pin? That seems a bit crude. > Canby one use the ARR product, and how do you connect the 12V to > it? > Bob > W0DXZ >

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Question about Frequencies to use on VO-52
by Ronald Nutter 31 Mar '08

31 Mar '08

I am trying to learn how to use the SSB birds. What are the "starting" frequencies that most use for uplink and downlink ? If I understand this correctly, you will leave the uplink set and then only tweak the downlink ? Thanks, Ron KA4KYI

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GVLB Tracker and Yaesu rotors
by Ronald Nutter 31 Mar '08

31 Mar '08

Since it may be a while before I can afford the az/el Yaesu rotor, is it possible to interface the current lvb tracker with an az only version of a Yaesu rotor ? I have been thinking of this since when I have my satellite antennas setup at home, I use a setup where my antennas are are pointed at a fixed elevation. Ron KA4KYI

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