[aprssig] Some 6M aprs notes I wrote up for Wes

Michael Chisena ka2zev at yahoo.com
Fri Mar 4 17:44:17 EST 2011

Guys,I sent Wes an off list answer, did not know that there was a general interest.Most of what I do is convert radios and make them into trackers.
Here  I took Wes's note and added my comments inside.Thanks for reading.Be well there.Mike ChisenaKA2ZEV

Hi there.

How I answer complex notes is to do a 'cut and paste' then interlace my
comments within.



Here's a direct message.... 


I'm wondering if 6m would be a good place to put aprs.  

(So far it's been a good experiment here in Fairfax Co. Virginia.

We have one big digi in the middle of Fairfax.
It has about a 30 mile range.


There is a small coverage unit in Annapolis MD
on the grounds of the Naval Academy.

When I just looked seems to be off the air. 

Like any experimental project some things work well and some don't. 

Tech as well as humans. 

A good RX in Reisterstown Md.


We just put up a new one in Bluemont VA,
that has some teething issues.



I'm also considering that since it's a NEW place, maybe we could develop it
with perhaps FEC or something a little more robust than ax.25.  

(Please don't do that on 50.620. 

This system working with 'standard' signals. 

It works fairly well. 

Might be cool to see what happens during skip season when distant stations can
ping each other. If you guys use exotic signals we will crash each other rather
than get useful data.

My thing is to build hardware. 

I convert radios and document the methods. 

I know very little of the computer stuff  you are talking about.

For simplicities sake we are using 6M duplicates of the standard conversion used
on 2M.

I have 'dual band' set ups in my vehicles.

KA2ZEV-6 is teamed up with 


and KA2ZEV-5 is teamed up with


Even and Odd if you will.

Bob WB4APR has one of my 6M sets. 

Bruce K7BC has a few as well.

In my cars the radios share a GPS puck.

Since it’s all CMOS I/O’s no reason to spend the extra money on pucks.

In the -8 they are duplexed into a dual band antenna, and in the -9 separate

The 2M sets are good for about 40 watts, and the 6M sets make about 50.  )

If ya gotta start new, why not consider new options.  

(This was done as a stepping stone for one of Bob's other ideas of using meteor
bounce to cover truly wide areas. 

Once people get used to conventional 6M APRS then we were going to start on the meteor
scatter project using a different frequency.)

It's not like Joe Ham with a d700 can qsy to 50mhz with their built in TNC.

(My giggle is to use less than $20 on EBay surplus LMR radios for this and
leave the agile ham stuff alone.)


Article links.

Just a note.  

With commercial radios, they use a common interface.

So the conversion that works for a 2M set works just the
same for a 6M set. Saves lots of trouble re inventing the wheel.

This is for the older Midland Syntech 1 sets.


This is for the more modern Midland XTR radio


Conversion article for the TT3 kit.


$40 GPS sensor conversion.


This is the most recent edition of a TT4 6M digi article.


Bruce K7BC is testing this to see if it's suitable for service in 'high

Other TT4 Projects.


Other APRS projects.


So you get the idea.


Keep it simple.

Then people will sign on to it.


Bruce is thinking about moving much of the critical APRS
stuff off the very busy 2M channel and expanding the 6M system for the next
Marine Corps Marathon.

The hope is to have a new digi on the grounds of the


If it’s one of mine, so much the better. (Never discount the
value of ego gratification.)


Couple of tips for your team.



Most ham 2M 5/8’s wave antennas make good 6M ¼ wave units. 

Try it and see. MFJ makes a very inexpensive mag mount for
about 30 bucks.

6 and 2 duplexers are cost effective.



Radios are cheap and getting cheaper. The standards are
changing on VHF and UHF. This stuff is sold for scrap. Some towns give away
their old radios for public service duty. This trick works just as well with
Motorola and GE gear as with the Midlands. 


Plastic adapters.

The advantage of the midlands is the availability of custom
cast plastic parts. Have a guy in New York
that took my examples and has made some fine duplicates in resin.

He is making 20 more for me. I’m expecting a good summer
making and marketing radios.


If you’re truly stuck for ideas here is one.

If you cover costs I can make up a tracker or a TT4 digi. 

I will donate one of my 6M 110 watt mobiles plus the labor
to convert it.

Take it, put it on the air and see what happens.

The goal of my conversion radios is  simple, rock solid ability.

Build it, install it, forget about it until trade in day. 

Got about 30 converted so far. 

They have over 330K hits into the system. 

The one in my truck has 41k of that number. 

Not bad for a project.


Keep it safe

Mike Chisena



703 863 4574 until 2100 eastern

"You are, what you do, when it counts"  

The Masso

"Gravity, the quickest way down"  

Mayor John Almafi

"You ever drop an egg, and on the floor you see it break? 

You go and get a mop so you can clean up your mistake.  

But did you ever stop to ponder why we know it's true? 

If you drop a broken egg you will not get an egg that's new?" 

MC Hawking

--- On Fri, 3/4/11, aprssig-request at tapr.org <aprssig-request at tapr.org> wrote:

From: aprssig-request at tapr.org <aprssig-request at tapr.org>
Subject: aprssig Digest, Vol 81, Issue 4
To: aprssig at tapr.org
Date: Friday, March 4, 2011, 7:00 AM

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Today's Topics:

   1. Re: 6m aprs? (Patrick Wood)
   2. Re: 6m aprs? (Bob Bruninga)
   3. Re: APRS on HF (John McHugh)
   4. RTrak-Lite Available and Shipping Now! (Jason Rausch)
   5. Re: Possible Opportunity For APRS (Steve Noskowicz)


Message: 1
Date: Thu, 3 Mar 2011 11:34:07 -0500
From: Patrick Wood <winston at winston1.net>
Subject: Re: [aprssig] 6m aprs?
To: TAPR APRS Mailing List <aprssig at tapr.org>
    <AANLkTimBP_at_FMf3i8SEhm8SibsVB29HStaFu12o_Ci at mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"

On Wed, Mar 2, 2011 at 7:49 PM, Stephen H. Smith <wa8lmf2 at aol.com> wrote:

> For 40+ years, the FM calling channel in SoCal has been 50.3 rather than
> the classic 52.525.    6M AM activity is semi-regular on 50.4 MHz.   And
> packet/data (beginning with RTTY!) has been on 50.62 for at least 30 years
> or more.

The 50.62 frequency use goes back to some experiments Bob and others appear
to have done in 2009, but there's little mention since then.  If there is
not a dedicated frequency, perhaps there should be one..  Especially if
50.62 is generally used for other purposes, may not want to step on the toes
of people using it if 6m aprs usage spreads...

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Message: 2
Date: Thu, 3 Mar 2011 15:31:13 -0500
From: "Bob Bruninga" <bruninga at usna.edu>
Subject: Re: [aprssig] 6m aprs?
To: "'TAPR APRS Mailing List'" <aprssig at tapr.org>
Message-ID: <036f01cbd9e1$f0866680$d1933380$@edu>
Content-Type: text/plain;    charset="US-ASCII"

> The 50.62 frequency use goes back to some experiments 
> Bob and others appear to have done in 2009, but there's 
> little mention since then....

Actually, it goes back to the original packet band plan AMRAD proposed back
in the 1980 time frame.  It was the first packet channel on 6m when packet
just started to get going.


Message: 3
Date: Thu, 03 Mar 2011 17:13:33 -0500
From: John McHugh <johnk.mchugh at bellsouth.net>
Subject: Re: [aprssig] APRS on HF
To: TAPR APRS Mailing List <aprssig at tapr.org>
Message-ID: <4D70128D.8020603 at bellsouth.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Julian, G4ILO wrote:

>What is the purpose of APRS on HF? Most of what I have read about APRS
>has said that the purpose of APRS is to provide *local* information.

Whilst APRS is used alot for "local" information I have used HF APRS 
over the years as a means to establish a kinship with some of my fellow 
hams in various parts of the US and the Caribbean basin. I've also used 
it to gather weather information from those same areas whenever a 
hurricane is in their vicinity. This as worked well with PJ6 and VP5 
lands in particular in recent years and when I first started with a 
weather network in Haiti run by HH2B. Gating from HF to VHF is  good but 
not the other way round.
The beauty of APRS is that we all use it for different purposes. It's a 
very versatile tool.

Sorry for the delay in responding but I was away on a trip with no Inet 


John Mc Hugh, K4AG
Coordinator for Amateur Radio  
National Hurricane Center, WX4NHC
Home page:- http://www.wx4nhc.org


Message: 4
Date: Thu, 3 Mar 2011 15:55:38 -0800 (PST)
From: Jason Rausch <jason at ke4nyv.com>
Subject: [aprssig] RTrak-Lite Available and Shipping Now!
To: aprssig at tapr.org
Message-ID: <513629.68405.qm at web1115.biz.mail.sk1.yahoo.com>
Content-Type: text/plain; charset=us-ascii

A limited quantity of the RTrak-Lite is now available for ordering and immediate shipping! Please see our website for details and ordering links:


Jason Rausch - KE4NYV
RPC Electronics, LLC


Message: 5
Date: Thu, 3 Mar 2011 18:45:58 -0800 (PST)
From: Steve Noskowicz <noskosteve at yahoo.com>
Subject: Re: [aprssig] Possible Opportunity For APRS
To: TAPR APRS Mailing List <aprssig at tapr.org>
Message-ID: <241002.14176.qm at web112615.mail.gq1.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

In the order received...

--Steve, K9DCI wrote:
> I have some answers, so no need for further responses.

Aw, but I just finished my query!

| COUNT(*) |
|      267 |
     Tom KD7LXL

Thanks Tom, that agrees well with Pete's (direct email).  

However, upon further thought, I realized that all mobiles, not just truckers, would be the better potential market number for an APRS GPS.

Soooo  Pete said that was more difficult, but gave an estimate of 19,000 in North America.  If you want to run something, go ahead.  No need to send the script it means nothing to me anyway. 

 THEN ...

--- Bob Bruninga wrote:
> ... the number of APRS truckers is probably only 2% 
> of the total number of truckers with a ham license.? ...
> Bob

 Good point!  While it'd be nice to know the real (2%) number, pointing this general fact out can help the cause.

  I'll also have him contact you directly.  He said you helped him with another issue some time ago.  Perhaps you can give some advice about dealing with a manufacturer in this regard.  Unless, of course, you have a limiting NDA.
73, Steve, K9DCI



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