Not all FT-847's are alike. A stock FT-847 has wide, low-Q ceramic IF
filters. My FT-847 has INRAD CW and SSB crystal filters that give
narrower IF bandwidth, with MUCH higher Q. I haven't compared them, but
I suspect that a FT-847 receiver with quality IF filters performs
roughly on par with an IC-910.
If shopping for a used FT-847, look for one with optional IF filters.
Collins mechanical filters are an improvement over the stock ceramic
filters, but crystal filters are even better.
Wayne Estes W9AE
Oakland, Oregon, USA
Let’s split your question into two parts
Car and House:
I have made literally hundreds of FM voice contacts with Mir and ISS from my car. I have also made hundreds of packet mail contacts with Mir.
On Mir the default power setting was 5 watts, into a Larsen Dual band Mobile antenna, mounted outside on the hull of Mir. The transceiver was either a Kenwood TM-733 or TM-V7A.
My car station was typically a 5/8 wave mono band 2-meter vertical, with a 45 watt class FM rig. I usually did not have the amps in the car since mobile amps are typically high maintenance.
ISS is running a similar setup. The transceiver is a Kenwood TM-D700, modified for three power settings, 5,10,25 (special mods). The ISS D700 has been programmed to default to 10 watts for voice and packet, unless changed by the crew, however every time the crew pushes a PM/function button, it forces the radio back to 10 watts.
The antenna is a Quad band system with 2, 440, patch for 1.2-2.4 Ghz. Gain is unknown, and must be assumed to be –3dBd for 2 meters.
So for beginners, LEO satellites, Running simple verticals and a 45+ watt class system and 0 dBd gain antennas is a good way to start from your car (parked or driving).
You will need to Pick your orbits in advance. I would usually only attempt orbits that were 45 degrees elevation or better from my Car.
For the more advances mobile users, try this Mobile EME array.
http://www.garysicecream.com/may909.htm
Other Car Tips:
Convert from RG-58 to LMR-240-UF or RG-213. The coax that usually comes with stock mobile antennas is too poor of quality to be used seriously.
Run Mono-band antennas for 2 and 440, get the highest Gain mono band (whip) antennas that will fit your mobile and garage. You may need a signal splitter since most rigs only have one SO-239 for 2/440.
Amps for your Car:
Get best antennas and coax first before using amps. In some States, we are limited to 50 watts on 440.
House Satellite Antennas:
It’s ok to start with a few simpler verticals or small beams to see if you like the satellite hobby.
If you do like Satellites and want to continue then you have two choices.
#1 Gradually build your antenna gain over several years,
1 Element 0 dBd
2 Elements 3dBd
4 Elements 6dBd
8 Elements 9 dBd
etc.
or
#2 you can jump in and buy a one of the 20+ element CP (circular polarized) 12-dBd class beams.
In many cases it maybe cheaper to go from 0 dBd to 12 dBd than buying lots of little antennas in-between. A CP style antenna system can be used for both Satellite and terrestrial DX.
Other Tips:
Go with the most elements you can afford for a single boom.
20+ elements on 2-meters
40+ elements on 440
Coax:
You can now get Flexible thick coax that will support an antenna Rotor.
Most people used RG-8 style coax, which is approximately 10 mm in diameter.
However you can now get flexible rotor grade coax which is approximately 15 mm in diameter, and has much lower loss than the best RG-8 style coax.
Example:
Belden RG-213
145 MHz 2.5 dB loss per 100 feet
438 MHz 4.5 dB loss per 100 feet
LMR 600 UltraFlex Rotor cable
145 MHz 1.1 dB loss per 100 feet
438 MHz 2.0 dB loss per 100 feet
As you can see, by switching from 10mm coax to 15mm coax you can reduce you loss by over 50%. The 15mm cables cost 2-3 times as much, however you will not have to worry about coax losses any more on Frequencies below 2 gig.
73 wf1f
--- On Fri, 5/29/09, Eric Fort <eric.fort(a)gmail.com> wrote:
> From: Eric Fort <eric.fort(a)gmail.com>
> Subject: [amsat-bb] eggbeater rx performance
> To: "Amsat BB" <amsat-bb(a)amsat.org>
> Date: Friday, May 29, 2009, 9:17 PM
> I/m interested in the possibility of
> using oscars 27, 29, 50, 51, and 52
> without using rotors or directional antennas and maybe
> while mobile. Uplink
> seems not to be a problem as one can always QRO to a level
> where the
> satellite sees an apropriate signal level that is enough
> but without robing
> power from other transponder users. On recieve though
> you still gotta be
> able to hear 'em to work 'em. Is an eggbeater and a
> preamp enough to hear
> decently or is there another (better) way? Is working
> mobile and/or without
> directional antennas even practical? what's the best
> way to do it?
>
> Thanks,
>
> Eric
> AF6EP
> _______________________________________________
> 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
>
Hello David,
For what seems like an eternity GO-32 has been sending a telemetry
packet at 9600 baud one per minute. So, NO, the BBS isn't open (and
hasn't been for a long time).
You can decode the telemetry GO-32 frames thanks to Mike DK3WN!
Actually, he has decoders for just about every satellite ever launched
;) at http://www.dk3wn.info/software.shtml
73,
--
Mark L. Hammond [N8MH]
______
Hello All,
What is the status of GO-32? Is the BBS back up and running?
73 de David VK5DG
Hi Bob,
You comments are valid for 2-meters. You are not going to see much difference between 15 feet of cheap coax and good coax. Howver, as you go higher in frequency the losses increase.
On the 440 band the Coax Loss difference between 15 feet of RG-58 and LMR-240 is approximately 1 dB.
For Raw power, switching from 15 feet of RG-58 (~5 millimeter cable) and LMR-240 (-6 Millimeter cable) will give you 15-20% more RF at the antenna.
So for people that are counting dB’s in mobile setup, this is just one more option to squeeze out a little more performance.
And for those of you what want to run amplifiers on 440, you will find that RG-58 has approximately a 105-watt limit. The LMR-240 (-6 Millimeter cable) will support 380 watts.
Here in Boston, Hams are starting to used 900 Mhz repeaters. The stock RG-58 coax just sucks up your TX and RX power on 900 mhz.
Low Loss Coax for Home and Mobile usage
Hi all:
Most of the mobile antennas mounting systems that come with coax use the
cheapest and highest loss coax available. If you read the fine print
on these coaxes you will be surprised to find that your power loss may
be as high as 40% and the coax will melt above 110 watts (on 440 mc).
More and more of us are using 440 and higher frequencies. By selecting
the correct coax you can save 1 or more DB of loss, even for a short
length as 15 feet.
Here are some number I put together on coax loss for the typical mobile
installation.
dB Loss (440 mc) dB Loss (900 mc)
Length FT TX Freq/Length
15' 100' Pwr 15' 100' Pwr
Size Center
RG-58/U 1.5 9.9 105w 2.2 14.5 60w .195"
.032
RG-58/A 1.5 9.9 105w 2.2 14.5 60w .195"
Stranded
RG-8X 1.2 8.1 250w 1.8 12.1 150w .240"
Stranded
LMR-240UF 0.5 3.2 380w 0.7 4.7 260w .240" .059
The coax RG-58 comes in many flavors, No letter, A, C and U.
The letter "U" is sometimes a solid 20 AWG copper center.
The letters "A" and "C" are stranded, the center size would be similar
to solid, and will have a little more loss than Solid center.
Most mobile installations will need 15 to 17 feet of coax.
RG-8X and LMR-240 are the same size, however LMR has foil shield and
lower published loss values. The UF version of 240 is the Ultra Flex
flavor and can bend easier with a only a slight change in loss ratings.
>From this list of small car style coax, the LMR beats them all; in
lowest loss for the size and highest transmit power loads. I was
planning on installing a 440 AMP in my car, but after looking at the
coax, I realized that I would fry the stock RG-58 coax.
I was looking for an NMO Mag mount that has LMR-240 installed. I was
not able to find any, so I made my own. I took a Round style Larsen NMO
mount and replaced the existing RG-58A coax with LMR-240. Use two screw
drivers to pop the magnet off the metal mount. Remove the two Phillips
screws hidden under the magnet. Remove the metal frame and now you will
have access to the coax mounting point. Replace coax and glue on the
magnet with epoxy cement.
145 meg
45 watts, in, 15 feet of LMR-240, = 40 watts out
45 watts, in, 15 feet of RG-58, = 37 watts out (~10% power loss difference)
440 meg
20 watts, in, 15 feet of LMR-240, = 17 watts out
20 watts, in, 15 feet of RG-58, = 14 watts out (15-20% power loss difference)
900 meg
10 watts, in, 15 feet of LMR-240, = 7.7 watts out
10 watts, in, 15 feet of RG-58, = 5.8 watts out
Power reference
http://www.ocarc.ca/coax.htm
73 Miles
--- On Sat, 5/30/09, Bob Bruninga <bruninga(a)usna.edu> wrote:
> From: Bob Bruninga <bruninga(a)usna.edu>
> Subject: [amsat-bb] Mobile Coax?
> To: "Amsat BB" <amsat-bb(a)amsat.org>
> Date: Saturday, May 30, 2009, 10:48 AM
> > Other Car Tips:
> > Convert from RG-58 to LMR-240-UF
> > or RG-213.
>
> I'd take that with a grain of salt. The length of
> coax in a car is about say 10 feet. The loss of 100
> feet of RG-58 is say 5 dB? and the loss of fancy stuff might
> be 3 db? But the diffrence for only a 10 foot run is
> only .5 dB versus .3 dB or only 0.2 dB. Nothing at all
> to even consider compared to all the work it will take, and
> the lack of flexibility and trying to run something almost
> like pipe through places where a simple wire (RG-58) fits.
>
> My lesson was learned 40 years ago when I go my first 100
> lb UHF mobile rig (tubes) just after highschool. The
> boat anchor filled the entire trunk of my MGB. But the
> first thing I did when we go the lot of them in my club was
> spend a day replacing the 8" internal piece of RG-58 in mine
> from the Transmitter output over to the chassis connector
> with a 8" run of RG-8. It was hard work getting that
> 8" piece of RG-8 coax inside the radio and routed all around
> the internal chassis.
>
> The elmer at the time laughed. He said you just
> wasted a day and all that work to save 0.01% of loss.
> So now your radio works at 100% where as before it worked at
> 99.99%. Losing 3 dB of course is one thing (50%), but
> trying to worry about that last 1% when the effort is
> tremendous is just not effective.
>
> Anyway, just my 2 cents...
>
> Bob, Wb4APR
> _______________________________________________
> 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
>
I/m interested in the possibility of using oscars 27, 29, 50, 51, and 52
without using rotors or directional antennas and maybe while mobile. Uplink
seems not to be a problem as one can always QRO to a level where the
satellite sees an apropriate signal level that is enough but without robing
power from other transponder users. On recieve though you still gotta be
able to hear 'em to work 'em. Is an eggbeater and a preamp enough to hear
decently or is there another (better) way? Is working mobile and/or without
directional antennas even practical? what's the best way to do it?
Thanks,
Eric
AF6EP
----- Original Message -----
From: "john heath" <g7hia(a)btinternet.com>
To: <eric.fort(a)gmail.com>
Sent: Saturday, May 30, 2009 8:48 AM
Subject: Re: [amsat-bb] eggbeater rx performance
> Hi Eric,
>
> For the downlink on 70cm why not have a look at the paraistic Lindenblad
> design by Anthony Monteiro AA2TX. Its small and neat, excellent omni
> performance and has been "on air tested" with good results on all sats.
>
> Much easier to construct than a true Lindenblad, I have built both types.
>
> Good luck.
>
> 73 John G7HIA
>
Hi Eric
If your goal is to work mobile while driving, your windows of opportunity
are going to be slim. I've done it, but effective air time will be pretty
short. On the portable side, I've been able to achieve VUCC Satellite using
5 Watts FT-60R handheld and an Arrow antenna mounted on a photo tripod
standing on the back deck. I also have the Elk but school's out on which I
prefer (for me- but most guys prefer the Elk). I've also built K5OE's
Eggbeater II for 2 meters which I have mounted in the attic along with an
antennas.us quadrifilar for 70 cm. Preamplifiers on both. Results are OK
but not as effective as even a simple directional antenna. I suspect that
the weak link is the quadrifilar and if I mounted a homebrew Eggbeater for
the downlink, it might improve results. Have also built EA4CYQ's "IOio"
handheld combo which works very well also. Go to http://www.eb4dka.tk to
see some great videos on how they work. Simple to build and effective for
portable work. Good luck.
73
Marc W4MPS
(formerly WA2S)
See if you can set explicit permission for satpce32 to be run as
administrator. I am presuming that the error is that the user doesn't have
adequate permission to run said program (or at least to make the change to the
'rotator north' parm).
Right click on the program icon, select Properties, Shortcut tab, Advanced,
check the box to run as another user...
73,
Lowell
K9LDW
------ Original Message ------
Received: Thu, 28 May 2009 07:36:09 AM CDT
From: "Nick" <quadpugh(a)bellsouth.net>
To: <amsat-bb(a)amsat.org>
Subject: [amsat-bb] help with satpc32
> The UL is running xp and satpce32 the xp is set with administrator and a
> user profile and will not store the rotator North point parameter .
>
>
>
> Help ????
>
>
>
> Thanks
>
> nick
>
> _______________________________________________
> 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
>
For mobile work on AO27, SO50, AO51 a 2 metre quarter wave whip is all you need with an IC-706 to work the LEO's when mobile and the satellite is 15 degrees or more above the horizon,
Regards
Mike G3LGR
