QRZ! Ham Radio 4/QRZ Ham Radio Callsign Database - Volume 4.iso/digests/space/940200.txt

Internet Message Format | 1994-11-13 | 12KB

Date: Thu, 21 Jul 94 04:30:37 PDT
From: Ham-Space Mailing List and Newsgroup <[e-mail]>
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Subject: Ham-Space Digest V94 #200
To: Ham-Space


Ham-Space Digest            Thu, 21 Jul 94       Volume 94 : Issue  200

Today's Topics:
                          Antenna questions
                       CONNECTING THREE MODEMS
                           Downlink signal
                            LES9 (2 msgs)
       WEFAX from PYE TELECOMMUNICATIONS PT AM 10DYV Receiver?

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We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party.  Your mileage may vary.  So there.
----------------------------------------------------------------------

Date: Tue, 19 Jul 1994 18:24:19 GMT
From: ihnp4.ucsd.edu!usc!elroy.jpl.nasa.gov!lll-winken.llnl.gov!quintro!rlile.glenqcy.glenayre.com![e-mail]
Subject: Antenna questions
To: [e-mail]

In article <9407181746.ZM13142@SALCIUS2> [e-mail] (Wayne_Estes) writes:
>From: [e-mail] (Wayne_Estes)
>Subject: Antenna questions
>Date: 18 Jul 1994 17:46:44 -0500

>I installed Az/El rotors on a tripod on my roof this weekend.  Next, I plan to
>buy some M2 antennas:   14 el. CP yagi for VHF
>                        30 el. CP yagi for UHF

>I must use the short VHF antenna because I have light-duty rotors, and a long
>boom would bump into tree branches and an exhaust vent.

>Can anyone answer the following questions?

>1. Is it (mechanically) easy to build a phasing/relay assembly for RH/LH
>polarity switching on the M2 antennas?

Answering the mechanical part of the question is simply and issue of having
space on the M2 boom for a relay box and the phasing line.

Assuming that the M2 comes with a 50 Ohm phasing line for generating the RH
or LH polarization, inserting a relay should not be hard.  Do you have the
information to do the phase shifting?

>2. Is the M2 crossboom really 10 ft.
long when assembled?

>3. Would a 7 ft. crossboom be long enough for VHF and UHF yagis on each end,
>and a future 2x3 ft. dish in the middle? (i.e. without undesired interaction
>between the antennas)

Yes, I have used 6 to 8 feet and have had no serious (read measureable)
problems with my set up.  Set up is currently, 12 turn helix on UHF and 10
element crossed yagis on 145 MHz.  Tripod mounted on 7 foot cross boom.
All homebrew by the way.

>4. Would a preamp at the VHF yagi feedpoint distort
the pattern of the>antenna?  Or should I mount the preamp on the mast?

Again mounting the preamp is mostly a mechanical issue.  However, you do want
to place it in the feedline before the phasing shifting relay.  My preamp
is mounted in an aluminum box on the tripod and works good.

>5. Do some preamp
models switch fast enough (PIN diodes maybe?) to allow me to>transmit
"through" the preamp without a timing circuit that bypasses the>preamp before
keying the transmitter?  If so, do these preamps require a PTT>line routed up
to the preamp, or do they detect the RF?

NO, please don't trust any switching method that doesn't use a timing circuit.
 The cost of the preamp vs the timing circuit has no comparison.

>Please
respond to [e-mail], or to the newsgroup.  Thanks in advance.

>73 de WD5FFH (Wayne Estes, Mundelein, IL)


>--
>Wayne A. Estes
>Motorola Asia-Pacific Cellular Subscriber Division
>600 N. U.S. Hwy. 45,  Rm. A-S345
>Libertyville, IL 60048-1286
>PHONE: [phone]       Z-MAIL: [e-mail]
>FAX: [phone]         POST: [e-mail]

------------------------------

Date: 21 Jul 94 00:17:40 GMT
From: [e-mail]
Subject: CONNECTING THREE MODEMS
To: [e-mail]

Message:
I'm cross-posting to Digital and Space because my questions concern
both, so a lot of people will see this twice.

I recently purchased a PacComm PSK-1 satellite modem and last
Saturday I purchased the PacComm TNC-NB96 (to celebrate getting my
Advanced and passing the Extra written cold, but that's another
story).  Now I have to figure how to connect everything together.  My
primary use will be the satellites, both PSK and 9600 FM, but I'm
sure I'll do some local stuff, too, now that I'm equiped.  The 2M rig
is an old Icom IC-251A and the satellite receiver is a Down East
Microwave transverter/Kenwood TS-670 combination.  Reading through
the literature, it looks like I'll be making a LOT of connections.
If anyone has any experience with a similar setup or can offer
suggestions, please pass them along.  What I need to know are things
like: 1) Will I have to have separate taps for xmit and rcv for each
mode? 2) Can I use some sort of switch box or relay scheme to route
the signals or will I be constantly plugging and unplugging? 3) Can I
use my direct connections for 9600 FSK for 1200 AFSK?  Has anyone
else got experience with the PacComm setup? Any suggestions for a good
terminal program?   Please post here.  Thanks in advance. Gary WA4YMZ

------------------------------

Date: 20 Jul 94 23:45:38 GMT
From: [e-mail]
Subject: Downlink signal
To: [e-mail]

Message:
Does anyone have any ideas about a problem I seem to have?  My
downlink signals seem to have a buzz as if there was bad filtering in
the power supply of my transmitter.  Last night I had a local ham
meet me on 144.200 and he says the signal sounds fine.  The equipment
here is an IC-251A and Mirage amp for uplink and an TS-690S for
recieve.  The noise is there whether the amp is on or not.  I noticed
the same thing on the FO-20 downlink yesterday but didn't hear it
today, so it isn't the reciever. The problem originally came up when
operating RS-10.  Any ideas or other input welcome.

Thanks in advance.

Gary WA4YMZ                  Gary [e-mail]

The opinions I express are mine alone. Data General doesn't want them
and I change them from time to time anyway.

------------------------------

Date: Wed, 20 Jul 1994 15:12:33 GMT
From: newsgate.melpar.esys.com!melpar![e-mail]
Subject: LES9
To: [e-mail]

Anybody know the location of a satellite known as LES9?  I believe it
is a geosynchronous bird.



Bruce Farquhar           | "The opinions expressed are mine; nobody
[e-mail]|         else would claim them!

------------------------------

Date: 21 Jul 1994 01:49:14 -0700
From: network.ucsd.edu![e-mail]
Subject: LES9
To: [e-mail]

In article <jbf.774717153@melpar> [e-mail] (J. Bruce Farquhar) writes:
>Anybody know the location of a satellite known as LES9?  I believe it
>is a geosynchronous bird.

Yes, it is a geosync, inclined almost 17 degrees, and sitting at about
106 degrees west.

LES 9
1 08747U 76023B   94200.91591465 -.00000102  00000-0  10000-3 0  6400
2 08747  16.6115 283.7785 0024551 111.5271 126.9263  1.00271924 12809

It's operating in the wide band mode at the moment, and you will find
the telemetry at 249.360

Occasionally you'll hear some weekend warriers on it, but other than
that, just some data and the BPSK signals from here.

Brent Jones
Amundsen-Scott South Pole Station
90 Degrees South,
Antarctica

------------------------------

Date: 18 Jul 94 03:40:50 GMT
From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!europa.eng.gtefsd.com!news.umbc.edu!hookup!reptiles.org!geac!herboid!cattnts!ncrcan!coutts![e-mail]
Subject: WEFAX from PYE TELECOMMUNICATIONS PT AM 10DYV Receiver?
To: [e-mail]

The issue: Can this receiver work at 137+ Mhz?

I have a PYE aircraft AM transceiver, that was modified to be a RX
only unit (which is fine), using the two crystal sockets for two different
receive frequencies, since the TX crystal is no longer needed.

The current crystals cause the receiver to receive 123.2 and 122.8 Mhz
at the moment. I want to receive the NOAA satellite WEFAX signals on
137.5 and 137.62 Mhz using this old receiver. The crystals currently
in there are in the:

    (123.2 - 10.7) / 3 = 37.5 Mhz neighbourhood (this is verified).

The 137.5 Mhz freq requires a 42.26666 Mhz crystal.

The receiver details:

PYE TELECOMMUNICATIONS Model PT AM 10DYV
Serial 1944D, input 12 Volts, and has 4 tubes, of which none are
required for receiving (receiver works with switch on standby, without
lighting the tube filaments).

It seems a bit of a stretch to go from a 37.5 Mhz crystal to 42.266 Mhz,
but there is a series connected inductor that is tunable (at least in
the current rendition of its wiring -- I don't have a schematic, so I
don't know if this is original or not).

I'm not sure how fussy the front end in this radio is... I doubt
any serious problem there. Again with no schematic, and without having
done much tracing from the antenna yet, its my opionion that there is
not much "tuned circuit" to discriminate 137 Mhz from 120 Mhz.

Anybody familiar (or not) with this radio, or someone with access to its
schematic wish to comment on this?  I'll have to get crystal(s) made
to try this, which is the reason for this post. Should I invest/waste
my money on crystals for this end?

Of course, I'm assuming that NOAA signals are AM audio signals. However,
if this should turn out to be FM instead-- no big deal. I can build a
demod circuit after the IF section. Email preferred, thanks.

--------------------
Warren W. Gay VE3WWG        John Coutts Library Services Limited
[e-mail]            Niagara Falls, Ontario, Canada
(or [e-mail], [e-mail])

------------------------------

Date: Wed, 20 Jul 1994 13:47:35 GMT
From: telesoft![e-mail]
To: [e-mail]

References <[e-mail]>, <[e-mail]>, <[e-mail]>
Reply-To : [e-mail]
Subject : STS-65 Element Set (94201.289)

STS-65
1 23173U 94039A   94201.28966185 +.00054802  00000-0  15851-3 0   423
2 23173  28.4662 281.0136 0003249  78.0464 282.0512 15.91226612  1864

Satellite: STS-65
Catalog number: 23173
Epoch time:      94201.28966185         (20 JUL 94   06:57:06.78 UTC)
Element set:     GSFC-042a
Inclination:       28.4662 deg
RA of node:       281.0136 deg          Space Shuttle Flight STS-65
Eccentricity:    0.0003249                  Keplerian Elements
Arg of perigee:    78.0464 deg
Mean anomaly:     282.0512 deg
Mean motion:   15.91226612 rev/day      Semi-major Axis: 6676.9815 Km
Decay rate:     5.4802E-04 rev/day*2    Apogee  Alt:        300.76 Km
Epoch rev:             186              Perigee Alt:        296.42 Km


--
Gary Morris            Internet: [e-mail]
KK6YB                  Packet:   KK6YB @ N0ARY.#NOCAL.CA.USA.NA
San Diego, CA, USA     Phone:    [phone] x128
--
Gary Morris                 Internet: [e-mail]  ([e-mail])
Alsys Inc.                  Packet:   KK6YB @ N0ARY.#NOCAL.CA.USA.NA
San Diego, CA, USA          Phone:    [phone] x128 (voice/fax)

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End of Ham-Space Digest V94 #200
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