Ham Radio/Ham Radio CD-ROM (Emerald Software) (1995).ISO/news/inham03/810

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INFO-HAMS Digest            Thu, 26 Oct 89       Volume 89 : Issue 810

Today's Topics:
                       Aviation NAVAIDS (long)
                       Cellular Phone via T.V.
                   Dipole antenna genius wanted...
                      INFO-HAMS Digest V89 #807
                info on Crystal Radio kit or schematic
                 Info on KENWOOD TR-2600 A needed!!!
                          KENWOOD TH-75A MOD
                   Looking for comments on ham dem
                Over-the-horizon Radar (was Re: Radar)
                 pre-novice seeking equipment advice
                                Radar
                       Where do YOU buy parts?
                              Wilson HT
                       Wondering about 455 kHz
----------------------------------------------------------------------

Date: 26 Oct 89 19:56:32 GMT
From: att!cbnewsj![e-mail]  (k.redden)
Subject: Aviation NAVAIDS (long)

In article <[e-mail]> [e-mail] (Michael Harpe) writes:
>
> Aviation NAVAIDS are some of the slicker applications of radio
> technology that you will ever find.
>
> ILS - Instrument Landing System.  System uses radio signals (I don't
> know what frequency, I think microwave) to generate a glide slope signal
> to landing aircraft.

The ILS is a combination of two transmitters in the VHF band (108 to
about 118MHZ). One is positioned a the far end of the runway and is called
the localizer. It is used to tell if the aircraft is right or left of the
course to the runway.

The second transmitter, called the glide slope, is positioned along side the
runway at the point where the aircraft is to touch down. It is used to tell if
the aircraft is above or below the proper glide path to the touchdown zone.

Together, the ILS provides a 3-deminsional precision approach to the runway.
The marker beacons are separate low power transmitters used to mark specific
points along the ILS approach.

>
> DME - Distance Measuring Equipment.  Related to VOR.  Gives a dead
> reckoning distance to the NAVAID generating the signal.

I beleive the DME uses an active interrogation by the aircraft DME transmitter
of the DME system that is co-located at some VORs. By timing the response,
the airborne system calculates the distance to the station. This is a measured
distance and not a dead reckoning position. Note that when directly overhead
the station, the DME will still show the distance (ie the altitude) to the
station. I think the DME operates somewhere around 1Ghz (the antenna is about
2 inches long).

Kevin Redden
WB2ZLF

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

Date: 26 Oct 89 15:32:00 GMT-10:00
From: "NORMAN FUNAMURA" <[e-mail]>
Subject: Cellular Phone via T.V.

1.  Background--Cellular phones occupy 824-848 Mhz (mobile) and 869-894 Mhz
(base).  FM is used and channel spacing is 30 Khz.  Mobile/Base spacing is 45
Mhz.  These frequency bands were formerly occupied by UHF-TV Channels 72-76 and
80-83+.  Shouldn't a TV be able to pick up these signals?????

2.  Connect an antenna to the UHF terminals of a TV.  If a UHF antenna is not
available, just use a piece of wire about a foot long with the ends connected
to the two UHF terminals.

3.  Turn on the TV and turn up the audio gain (TV's use much wider deviation).
Slowly tune around channels 80 and 83.  Occasional audio should be heard, but
because the TV audio section requires a 4.5 Mhz signal, audio will be heard
only when two cellular channels about 4.5 Mhz apart are active.

4.  A second TV (assuming higher local oscillator and about 45 Mhz IF) could
provide the necessary hetrodyne so that the first TV can detect a single
incoming signal.

     a.  Tune the first TV (with UHF antenna) to channel 82 (80-83).

     b.  Bring the second TV as close as possible to the first and slowly tune
         it around channel 75 (72-76), until audio is heard...or

     c.  Retune by small increments...set the first TV, then sweep the second
         etc.

5.  DISCLAIMER!!!!! Try this at your own risk......don't know the
legalities/illegalities of listening to cellular phones......



73  Norman
KH6R




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

Date: 27 Oct 89 00:42:54 GMT
From: [e-mail]  (Tom Taylor)
Subject: Dipole antenna genius wanted...

This past weekend I built a three band dipole antenna for the 40, 30, and
17 meter bands.  The antenna is the type with one center and three separate
legs, separated by spacers.  I tuned the antenna when it was about 5 feet
off the ground.  The antenna tuned very nicely with low SWR across each band
and 1:1 SWR somewhere in the band.  Next, I raised the center of the antenna
and mounted it near the top of my crank up tower.  At this point, the tower
was cranked down and the center of the dipole was about 25 feet in the air.
Each leg drooped down to about 8 feet in the air.  I checked the SWR and
found that the 1:1 low point had shifted down in frequency by about 200kHz
on the 40 and 30 meter bands (probably expected) and had not changed on 17
meters.  After tuning the antenna again to get 1:1 point in the middle of
the bands, I cranked up the tower to about 45 feet and raised the ends to
about 15 feet.  When I checked the SWR, I found that the low point on the
40 and 30 meter bands was no longer 1:1, but about 2:1.  Of course, the
band edges were at least 3:1 (instead of under 2:1).  The SWR on the 17
meter band was still ok.  What's the problem?  I can understand the SWR
low point shifting when the antenna was raised.  I can't understand,
however, why the SWR low point is no longer low.  Can anyone help?

Picture of antenna:
@-----------------------------------@@----------------------------------@
     |-----------------------------/  \------------------------|
                      |-----------/    \---------|

Tom Taylor - AA6BR

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

Date: Thu 26 Oct 89 21:03:28-CDT
From: [e-mail]
Subject: INFO-HAMS Digest V89 #807

subj: buying equipment cheap overseas
This is in reply to WF2K's question on buying equipment for a good price
overseas----
It aint worth it!  First off, the dollar is of such low value these
days that you can buy the same gear for less at the discount places
here in the USA.  Second, the warentee is practically useless...it is
almost impossible to get service from the stateside dealers on a Japanese
bought rig.  Third, many of the rigs overseas are not the same as those
sold in the states....for example, on their two meter rigs---they go from
144 to 146.oo MHZ...their band is not the same as ours...I found it
fun to look around the ham radio electronics district in Tokyo (called
Akie ---harbra)...I bought a few odds and ends, but nothing big....also, buy
a Japaneese CQ magazine...it's about an inch and a half thick!!! Its
hard (for me) to reed Japanese, but fun to look at the pictures!!!
Have fun,
73,
Marv, WG4Q
-------

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

Date: 26 Oct 89 21:54:37 GMT
From: uokmax![e-mail]  (NARC ONE)
Subject: info on Crystal Radio kit or schematic

In article <[e-mail]> [e-mail] (Sterling Huxley) writes:
>
>As a Christmas present I thought I would give my nephew a crystal radio kit.
>I've looked around and can only find a cheap kit from Radio Shack.
>[stuff deleted...]
>Does anyone know where a reasonable kit can be purchased?

The Radio Shack kit is, actually, acceptable.  I got one for Christmas when
I was nine years old, and it was quite thrilling.  To this day, I still have
it, and it still works.  Only thing you might consider adding on to the kit
is a longer antenna.  They only provide 10 feet of wire for the antenna, and
10 feet for the ground (at least, when I got mine).  It was kind of
disheartening at first, because the short antenna did not give enough
signal strength to pick up any stations at first, and I was afraid it didn't
work.  So, my advice is just stick with the Radio Shack kit and buy some
antenna wire to go with it, and your nephew should be quite happy.

--
Norman Lin

This is my humble signature file.

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

Date: 27 Oct 89 00:03:58 GMT
From: sco![e-mail]  (Steve Beecher)
Subject: Info on KENWOOD TR-2600 A needed!!!

   I have a Kenwood TR-2600 A that I have a couple of questions about.
First of all, I was wondering how to use the Telephone Autopatch system
for business and/or personal use, i.e. extra licences needed, who I need
to contact, how to operate it on my unit, where to find out the frequencies,
etc.  Is the TU-35B tone unit needed for this?  Do I need to buy one, or is
it something different entirely.  Secondly, I would like to know if there
are any mod.s available to increase the scan speed of the TR-2600 A.  It
is very slow as is stands.  Anyone with answers to either of these questions
I would appreciate email to me.  Thanks!!!!


-------------------------------------------------------------------------------
              Steve Beecher
              Software/Hardware Technician
              Computer Services
              The Santa Cruz Operation
              E-mail:  ...!uunet!sco!stevebe      [e-mail]
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------

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

Date: Thu, 26 Oct 89 15:19 CDT
From: SURESH KAGOO N9GSA/4S7??? <[e-mail]>
Subject: KENWOOD TH-75A MOD

TH-75A MARS/CAP MODIFICATION
----------------------------

This modification will allow the TH-75A to transmit from 142 to 152 MHz and 420
to 450 MHz. Specifications are guaranteed for the Amateur Bands only. Through
the transceiver will display 136 to 174 MHz and 335 to 512 MHz, the PLL circuit
may not lock through the entire range.

CAUTION
-------

Protect your license. Make sure that you operate  on authorized frequencies
only.



MODIFICATION PROCEDURE
----------------------

1.      Disconnect the battery and antenna.

2.      Remove the three case screws and two battery plate screws.

3.      Lift the front panel from the body of the transceiver, but do not
        disconnect the two flex cables.

4.      Cut the green jumper wire (W1) that is located to the left side of
        the CPU in the front panel assembly.

5.      Assemble the transceiver by reversing steps 1-3.

6.      Reset the CPU by holding the M key as the power is turned on.


I have tried it and it works.

Suresh Kagoo  N9GSA/4S7???       Memphis State University
                                 Memphis, Tennessee

                                 Internet : [e-mail]
                                 Bitnet   : SKAGOO@MEMSTVX1







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

Date: 27 Oct 89 00:40:26 GMT
From: gem.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu![e-mail]
Subject: Looking for comments on ham dem

> 1. Remember that they probably don't understand how a flashlight
> works.  Demonstrate electric shock:  Connect a few 9v batteries in
> series, enough to feel with wet fingers.  Use kids holding hands to
> demonstrate series circuits.  Demonstrate again using battery,
> lightbulb and switch.  Let them play with it for a while.

Definitely **DO**NOT** do this.  An electric shock across the heart (such
as would be the case in a chain of kids holding hands) can be **FATAL**.

Limit demonstrations of electric shock to where the electric path does NOT
involve the heart or other organs.  A wet finger and 2 9v batteries might
be OK.  You might also try touching the tip of your tongue to a single 9v
battery (or lesser voltage from other cells).

Another demonstration you might try is this:  take a couple of lantern type
batteries in series for 12-24 volts, and attach one end to a tin can with
all it's metal exposed.  In the other, use a clamp of some sort to hold some
thin (30 gauge or so) metal wire.  Have a lot of the wire on hand.  Touch
the wire to the can and see a quick spark and let it fuse to the can.  Now
the wire will be heating up due to the short and will soon break in the middle
after it turns red.  Repeat the process in several places on the can and you
will soon have a "hairy" can.

--Phil Howard, KA9WGN--
<[e-mail]>

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

Date: 26 Oct 89 23:23:43 GMT
From: attctc![e-mail]  (Steve Sampson)
Subject: Over-the-horizon Radar (was Re: Radar)

For those interested - The OTH-B Over The Horizon Backscatter radar on the
east coast is operational with about 180 degrees of coverage.  A west coast
system is nearing completion.  The final site in the Dakotas will look south
180 degrees.  North looking has been a problem due to the Northern lights and
otherwise poor propogation.  These HF radars use the Ionosphere to bounce the
radar pulses in vertical and horizontal sweep.  They are very long range and
have no short range capability (say inside 200 miles).  There are also many
portable systems in use by the Navy, while the USAF is only interested in
fixed sites.  Portable meaning rapidly set up, not small.

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

Date: 26 Oct 89 21:11:57 GMT
From: m2c!umvlsi!dime![e-mail]  (DYRK)
Subject: pre-novice seeking equipment advice

    I am seeking some advice from the net about equipment in
    general.
    I am currently studying for my novice exam. I am also finishing
    my dissertation in CS so I have little time to visit clubs etc.
    Just enough time to squeeze in some code practice between
    research and writing diss.

    There are various sources that say one should start out with an
    "economy" transceiver (I guess this means the low end Kenwood,
    Yaesu, Icom HF transceivers, CB, SSB, etc. mode, 160 to 10 m,
    100 or 200 W PEP),
    even though novice priviliges dont allow
    one to use it all the features immediately. Buying such a thing
    would give immediate success which is important for a novice.
    They are also useful when upgrading.

    On the other hand I do like to tinker and build my own
    equipment. I could not find a kit or something like that for a
    so called economy transceiver. The only thing is a QRP kit from
    Heath which definitely does not fall in the above category.

    Are there other kits or sets? Should one start with  QRP
    anyways? Is it best to initially forget about building yourself
    and buying something solid? I'm quite confused.


    Thanks for your help,

    Dirk Mahling

    [e-mail]

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

Date: 27 Oct 89 00:40:20 GMT
From: gem.mps.ohio-state.edu!wuarchive!uwm.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu![e-mail]
Subject: Radar

>     I think not.  The Krasnoyarsk site was unfinished, whereas the Russian
> woodpecker has been around for years.

I've heard that it is in fact actually operating, and is simply not fully
implemented as their original plans were to have it.  I still don't know
the specifications.  I know that both THEY and WE are using and/or planning
to use less obvious spread spectrum.

--Phil Howard, KA9WGN--
<[e-mail]>

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

Date: 26 Oct 89 21:35:00 GMT
From: ux1.cso.uiuc.edu!ux1.cso.uiuc.edu![e-mail]
Subject: Where do YOU buy parts?

> Though I have catalogs for all of the following:
>
>     All Electronics
>     Amidon Associates
>     Circuit Specialists
>     DC Electronics
>     Digi Key
>     Fair Radio
>     Jameco
>     Newark
>     RadioKit
>     Star Electronics
>     Surplus Sales of Nebraska

Can you post phone numbers (800 numbers preferred)?  That way we can all
call them and ask for catalogs and say we heard it on USENET:rec.ham-radio
or INFOHAMS Digest.

--Phil Howard, KA9WGN--
<[e-mail]>

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

Date: 27 Oct 89 00:40:41 GMT
From: cs.utexas.edu!swrinde!gem.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu![e-mail]
Subject: Wilson HT

> I have resurrected my old Wilson Mark IV HT after many years of inactivity, and
> find the NICAD battery pack is shot. I tried to call Wilson, but they appear
> to be out of business.
>
> Does anyone out there:
>
>              1.) Have a battery pack they'd be willing to sell ? or,
>              2.) Know where I could get one ? or,
>              3.) Know what became of Wilson Electronics (based in Las Vegas) ?
>
> Thank you for any information you could provide.

Call places like Periphex, W&W Associates, and Mr. Nicad (ads in QST and HR
magazines) and see if they have replacement cells or inserts.

--Phil Howard, KA9WGN--
<[e-mail]>

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

Date: 26 Oct 89 14:58:12 GMT
From: asuvax!stjhmc!f1.n234.z1.fidonet.org![e-mail]  (Jim Grubs)
Subject: Wondering about 455 kHz

 > From: [e-mail]

 > Does anyone out there know how 455 kHz got to be such a popular IF ?
 > Why 455, (as opposed to 450 or 500, e.g.)?

So broadcast band images would not fall inside the band.


fall inside the band.

--
Uucp: ...{gatech,ames,rutgers}!ncar!noao!asuvax!stjhmc!234!1!Jim.Grubs
Internet: [e-mail]

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End of INFO-HAMS Digest V89 Issue #810
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