View Full Version : Converting Commercial FM to Ham

10-25-2007, 07:25 PM
There is a large auction coming up on Saturday, Oct 27th. A communications dealer went belly up. Among items listed are towers, cable, and "large lot of Commercial Handheld radios" and "Large lot of Commercial Base station radios."

I realize if these are newer "programmable" units, many are not "re-progammable". But I only know about Wilson and Regency brands.

Is there any chance these units, (I presume 250Mhz and 400 Mhz) could be easily modified and, if so, is there any advantage to doing so, other than the educational value?

Hugh - KDBQM

10-25-2007, 07:27 PM
Quote[/b] (KD0BQM @ Oct. 25 2007,12:25)]There is a large auction coming up on Saturday, Oct 27th. #A communications dealer went belly up. #Among items listed are towers, cable, and "large lot of Commercial Handheld radios" and "Large lot of Commercial Base station radios."

I realize if these are newer "programmable" units, many are not "re-progammable". #But I only know about Wilson and Regency brands. #

Is there any chance these units, (I presume 250Mhz and 400 Mhz) could be easily modified and, if so, is there any advantage to doing so, other than the educational value?

Hugh - KDBQM
never pass up a free radio

10-25-2007, 07:30 PM
These won't be "free" but I might be able to get at a "decent" price. If modified, could they be used/sold as Ham equip?

Hugh - KDBQM

10-25-2007, 07:37 PM
I "assume" that you mean 150 MHz and not 250 MHz!

If they are programmable and if you have access to a method of programming the radios then generally you will find that commercial two-way equipment has better specifications than most equipment manufactured for the amateur radio market and will perform better.

However, commercial two-way equipment cannot, in order to meet FCC certification requirements, be frequency programmed "from the front panel". Therefore, you cannot select random frequencies but have to program the radios for specific frequencies and tones (if required).

If you do not have access to a frequency programmer then you have to take into consideration the cost of getting the units programmed to the correct frequency. If the units are crystal controlled then you have to consider the cost of new crystals (generally one for the receiver and one for the transmitter for each frequency desired. For commercial grade crystals this generally ranges from $20 to $25 per crystal ($40 to $50 per channel).

Glen, K9STH

10-25-2007, 07:48 PM
OK, thanks. If the lots are to be broken up, I might buy a couple for parts. If I have to buy 50 of each, I'll let 'em go.

Tnx Agn.

Hugh - KDBQM

10-25-2007, 09:02 PM
A note. You will see a lot of commercial radios on eBay. Many of them are trunked. If these you mention are trunking radios, they are good only for resale on eBay, or for junk.

Good luck with the deal!

10-25-2007, 09:22 PM
Quote[/b] (W5HTW @ Oct. 25 2007,14:02)]A note. #You will see a lot of commercial radios on eBay. #Many of them are trunked. #If these you mention are trunking radios,
...you can sell the to the circus so the elephants can communicate! http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif

10-25-2007, 11:30 PM
There are a number of commercial 900 Mhz. radios that can be moved into the ham band coming available as surplus.

The AR902Mhz Group (http://groups.yahoo.com/group/AR902Mhz/) on yahoo will get you info on which ones are easy to convert, and which ones are real tough.

Some radio companies guard their programming code very closely, and others don't. You will find examples of this on the discussion group.

There's also commercial rigs capable of digital voice using APCO-25 allegedly available for a fraction of the new price.
Some of the folks here can give you guidance on converting them.

The last two QST's had a series of articles on converting a particular kind of commercial rig.

10-25-2007, 11:46 PM
If they have Motorola gear you can get all the information you would ever need on Batlabs.
Batlabs (www.batlabs.com)

10-26-2007, 04:58 AM
One other thing to watch out for:

If you can, get a list of model numbers and check them out on the internet to see if they are capable of operating on the amateur bands.

Many times, commercial radios, especially crystal controlled, non-programmable ones, will be able to operate only on a specific "split" of low or high band. Say from 147-159, then another range between 160-174.

Low band radios are more of a challenge.
They were commonly made to operate from 30-36 mhz, another split from 36-42 mhz and a third split from 42-50 mhz.
Named, Low-Low, Low-Mid, and Low-High.
If you bought a 30-36 split radio for 6 meter FM, it would be almost impossible to convert to 50-54 mhz without significant cost. (If it were possible at all)

In other words, make sure they are capable of operating without MAJOR changes within the amateur bands.

If you would get a radio that can operate on the higher split, then major changes may be necessary to make it operate on the lower split. Major changes as in, beside crystals, you may have to replace osc boards, capacitors, transformers etc.
That would make a BARGAIN radio, not so much of a bargain.

Chances are the stuff they have for auction will be newer equipment, but if a two-way shop has been in business for a long time, they may have stuff that should have gone in the dumpster long ago, but was retained for parts etc and may end up in the auction inventory.

Boy, I hope that made sense.


10-26-2007, 02:24 PM
There are some commercial radios made for 220-222. They are ACSB - amplitude compandored SSB -

That service is not all that popular - but thousands and thousands of radios were made.

They are not useful for 222-225 ham FM repeaters on 222 FM band.

Check out what you are buying ahead of time, otherwise you might wind up with near useless stuff.

10-26-2007, 07:19 PM
You've gotten good advice.

Some newer Motorola stuff cannot be programmed for the ham bands. Some lines of high band gear will not take entries outside the designed split of 150-174MHz, or UHF stuff outside 450-512MHz. So for hams, these are useless.

Trunking radios and all 800 MHz stuff is useless for hams, while someone said above 900MHz stuff can be though most with modifications.

36-42MHz lowband rigs are useless, while 30-36MHz stuff can often be programmed on 10m and 42-50 can sometimes be brought up to 6m.

This could be a gold mine for you or a pig in a poke. As KS4VT said, batboard.batlabs.com is excellent but only for Motorola. http://radio.the161.net/ is the place for other brand commercial rigs (populated by many of the same radio experts.)

Good luck. If you find a 30-36 MHz MT1000 I'll take it!

10-27-2007, 04:31 AM
I went down there today to look over what was all included in this "huge" auction. Hah! I repeat, "Hah!" The auctioneer is a new one in the area that has been dominated buy another auctioneer for years. So I guess he thought he had to make a big splash to get anyone there. JUNQUE! A couple lots of halfway decent stuff but the radios were all old junk. And when I say junk, I mean condition - dirty, missing knobs and faceplates etc. Only two things MIGHT be of interest - 1 1250 foot roll (about half missing) of #12 stranded copper antenna wire - exactly the same stuff they sell at ratshack for 5 bucks for 70 feet. Don't think it would be any good for 160M without at least a center pole for support. The other thing I saw was an old Hickock 8905A Scope. Asked the owner of the property (not they guy who would have been using it) if it worked and his reply was, "Yeah, it works. At least I think it does. Gee, I don't really know. Hmm."
They have this stuff spread all over a parking lot and most of the boxes are stuffed with anything that fits...Nothing sorted. I am not going to waste my money but I have to go 'cause a buddy of mine can't get his truck started and I told him I'd go so he could drag some junk home. So...that's my day tomorrow.

Hugh - KDBQM

10-27-2007, 07:40 PM
The popularity of today's VHF bands and FM modulation can be traced back to the 60's and 70's when surplus commercial equipment made the band popular.

Do your homework first . . . know the makes and models, and whether they are synthesized programmable or crystal controlled. Crystal control is fine for a couple of frequencies, but they get price prohibitive beyond that.

I'd stick with Motorola & GE, where service manuals are readily available. Others, like the RCAs, are almost impossible to find books.

Handheld radios are usually pretty hammered by the time they are surplused out, and I'd be extremely wary. Most require special servicing jigs and a good steady eye and hand to repair.

Overall, they'll provide exceptional performance over the "amateur" makes, and will last as long as you will. The downside is that unless you do your own installation/maintenance, those items can get pricey at the local 2-way shop at $100/hr or so.


10-27-2007, 11:43 PM
KKP hit the nail on the head. My VHF and UHF gear is exclusively Motorola. Yes it's excellent stuff and the receivers hear what they should while amateur rigs go crazy with intermod, etc.

But I always make sure to say what I have is a sickness. An expensive one!

10-28-2007, 10:04 PM
Well, the auction is over and another ham made some tremendous good buys on 2M repeaters. I, on the other hand merely bought an B+K Precision 2120 'scope for $12.50 (works great) a Shure Unidyne B mic for $2.00 and a para dynamics pdc 600 SWR Meter along with 10 good mobile speakers (including 7 Motorola) for another 2 bucks. The mic works, the swr meter works and the scope works. My day went good.

Hugh - KDBQM

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