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Conference vmszoo::rc

Title:Welcome To The Radio Control Conference
Notice:dir's in 11, who's who in 4, sales in 6, auctions 19
Moderator:VMSSG::FRIEDRICHS
Created:Tue Jan 13 1987
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1706
Total number of notes:27193

1017.0. "Conversion to HAM Frequency Questions" by NAC::ALBRIGHT (IBM BUSTERS - Who'ya going to call!) Thu Jun 01 1989 14:44

I've seen bit and pieces of information regarding this subject but never 
a note dedicated to it.

I find myself thinking about the radio I will end up purchasing for my 
Chipmunk someday.  With all the talk and concern about interference in 
the 72 MHz band my thoughts often turn to the 6 Meter ham frequencies.  
A few questions come to mind.  (I know, the first thing someone will 
say, "You have to be licensed."  I am, KA1GR.)

1. What is the general procedure for getting a radio converted?

2. Will manufactures convert all of their models or only some of them.
I have been eyeing the Airtronics Vanguard series.

3. Is any one vendor better at it or more agreeable to it.

4. Is there any noticeable affect on the range of the radio because of 
the conversion.  I know that the conversion of commercial two way 
radios to ham frequencies often affected their performance.  20 MHz is a 
long way to go at those frequencies.  Do they just recrystal and retune the 
radios or do they swap RF decks to accommodate the lower frequencies?

5. Any special considerations for skip?  I believe the sunspot cycle is 
near its peak and very long distance communications/interference is possible 
in the 6 meter band.   I once worked Havana, Cuba in my car on 6 
meters from Southeastern Michigan.  AM is probably out.  How about FM or 
PCM?

6. Since most 6 meter ham rigs these days are tunable throughout the 
band, is interference/jamming from these rigs a problem?

7. Though I am a very long way from competition, I thought I read 
somewhere that converted radios are not AMA legal at some AMA events.  I 
can't believe this would be true but I have to ask.  The AMA membership 
manual says that Amateur frequency use is at the discretion of event 
officials.  Should this be a concern?

8. The membership manual lists two groups of 6 meter frequencies, one in 
the 50 MHz region and the other in the 53 MHz region.  I get the 
impression the AMA and ARRL are pushing for the 50 MHz region to avoid 
problems with amateur repeater frequencies and possible TV Channel 2 
interference.  Comments?

I am still new to this hobby and the notes file has been invaluable in 
helping get up to speed.  Keep up the good work.

Loren
T.RTitleUserPersonal
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1017.1Ham answersLEDS::HUGHESDave Hughes (LEDS::HUGHES) NKS1-1/E3 291-7214Thu Jun 01 1989 17:3933
    I believe this is discussed in other notes, and if the moderators
    find it elsewhere please let us know and we'll move it.

    A brief answer is that "converting" your radio means replacing
    the RF module in the transmitter and the entire receiver.
    Airtronics does it for free if you send them a new -in-the-box
    72MHz radio, if it's one of the models that they support on 6
    meters (used to be just the CS7P, but some of the new models
    are also available on 6 meters).

    My personal opinions is that I don't think it's worth converting an
    older radio, you'd spend almost enough money to buy a new one. Sell the
    old one to a non-ham and buy a new one on 6 meters.

    As far as which band (50 or 53), the 50 MHz channels require narrow
    band equipment just like the 1991 72MHz does. 53 MHz is 100kHz
    spacing, and will NOT be obsoleted in 1991. If I was going to buy
    a new radio now, I'd try for 50MHz, but I'd first check to see if
    there are any repeaters around - they've put some down there at
    the bottom of 6 meters.

    Ham radios do not have to be type-accepted by the FCC, that is one
    of the privileges of being a ham. I don't know how AMA deals with
    this, but I'd be surprised if they objected. It is perfectly legal
    for a ham to build his own radios from scratch. It's also legal for
    a ham to operate R/C on ANY ham band, but I do think the AMA would
    restrict you to one of their "sanctioned" frequencies at any formal
    AMA meet.

    Dave Hughes
    WA1MPF

1017.2Buy it on 50/53!POBOX::KAPLOWSet the WAYBACK machine for 1982Thu Jun 01 1989 19:5028
        If you are buying a new radio (thats what your second paragraph
        implies), don't worry about "conversion", just buy one on the 6
        meter band. Many RC vendors don't offer this option, but enough do
        that you shouldn't have a problem getting one. You won't find one
        in your local store, or discount house. Thus it may be cheaper to
        buy one and convert it than to buy one at retail. Still, stick
        with a vendor who offers 6 meter gear and it should not be a
        problem. Airtronics does offer ham gear. 
        
        Conversion done by re-crystalling and re-tuning only works on
        close-by bands (business to 2 meter for example). This may result
        in a minor perfromance loss. It COULD be done on the cheap 49Mhz
        radios to 50/53Mhz, but they probably aren't worth the bother. To
        convert a 72Mhz to 50/53Mhz you would have to replace or
        re-engineer the whole RF deck. 
        
        My understanding is that the new ARRL band plan for 6 meters
        has NO repeaters anywhere near the 50.xx narrow band channels.
        There may be repeaters on either side of the 53.x0 channels,
        just as close as the pagers on 72.xx.
        
        As to competition, both the 50.xx and 53.x0 frequencies should be
        permitted. They ARE part of the AMA band plan. Of course you must
        show your FCC license. Other legal ham frequencies are at the
        option of the CD. Your membership handbook should explain all of
        this, and tell you the proper flag/number to use. 
        
	Bob WB9WDV
1017.3Piece of cake...CLOSUS::TAVARESJohn -- Stay low, keep movingFri Jun 02 1989 18:1712
If your radio is AM, and if you are a ham, you should be able to
get an RF deck from Ace RC, 1991 ready, and install it yourself.

Its simply a case of mechanically locating the deck; in the case
of my Futaba radio the Ace deck is about the same size and would
fit into the same place.  Then you need to hook up the output of
the present encoder, the meter input, and the power wires.  You
may need to invert the modulation as described in RCM recently
(if you need the article, let me know offline). 

Should be no problem for someone who can do dit dah dit at 5 or
more WPM.