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Narrowband Deja Vu

A bit of vintage ham radio history and
the start of amateur repeater operation

Think back to the time when SSB was new and AM was still common.  Remember when few hams operated "appliances" and most were not afraid to open up their radios? 

In the mid-to-late 1960's the concept of channelized ham repeater operation was considered by some hams as being too radical.  In fact, more than a few hams considered the use of crystal-controlled receivers as "not ham radio".   This new mode of operation was not endorsed by the then-conservative ARRL and even the FCC wasn't certain as to the the legality of ham radio repeaters.  How times change!  History may be repeating itself.

Hams have tended to convert surplus commercial band radios into amateur use about ten years after each product dominated the commercial scene.  Due to FCC commercial modulation bandwidth rule changes in the mid-60's, perfectly good equipment became surplus.  Commercial equipment prices were very low and the performance was very high. Hams eventually gathered to swap whatever parts and knowledge they had to share.  In fact, this was downright FUN !

                    GE Progress Line

GE's proud tube-type workhorse was known as the the Progress Line.  Above is a front-mounted FI or TI series  but most radios were installed into the trunk with only a control head showing under the dashboard.

The Progress Line was very popular as a 2-meter ham radio from the late-60's well into the late 70's.  Obtaining this surplus crystal controlled radio with the optional  "four freq deck" was a matter of on-air discussion and peer envy !

In the mid-60's Motorola came out with what many consider to be the best transistorized two-way radio introduction in history, the MOTRAC. The MOTRAC family was seen on Adam-12, Dragnet, Emergency and many other cop shows.


Obtaining and converting these great radios became a personal goal for many hams.  The duopoly-style competition between Motorola and GE was the subject of more than a few "Ford vs. Chevy" debates within the ham community .


         GE TPL  

To compete with the MOTRAC, GE introduced what many consider to be the greatest flop in two-way radio history, the GE Transistorized Progress Line or TPL.  GE actually re-purchased many of the dysfunctional TPL's and supplied customers with the older tube-type Progress Lines that actually worked.  Only the later iteration of TPL's (without the quirky delay-line modulators) were viable but the damage to the GE name took many years to correct.

Thankfully, the MASTR-Pro and MASTR-II replaced the notorious TPL. The GE MASTR-II series was a smashing success. Thanks to some vibrant third party aftermarket support, hundreds of MASTR-II ham repeaters are still on the air 30-years later ! The Motorola MICOR repeater also enjoys a similar stature among hams.

Motorola almost always dominated the portable market.  In the 60's, the HT200 became the first truly portable VHF "Handie-Talkie".  Some old NASA pictures showed Apollo ground crews with HT200's on the launch pad.  Real state of the art!  The smaller HT220 again dominated the portable market in the 70's.  Thanks to Spectronics in Oak Park, IL  and a benevolent Motorola in nearby Schaumburg, IL, many of the trade-ins made their way into ham radio use which only expanded  Motorola's cult-like following.   This was great long-term marketing!


At one time, converting these older commercial radios presented a very compelling value proposition for hams.  However as more repeaters proliferated, the need to buy additional crystals became cost prohibitive.  Except for the hard core enthusiast, commercial mobile radio conversions became the exception rather than the rule.  Of course the off-shore ham equipment manufacturers eventually dominated the end-user mobile market and with that, few hams would dare to tinker with these new feature-rich but almost sealed radios. This off-the-shelf market dominance continues to this day but some new and highly relevant exceptions are beginning to appear at hamfests and via eBay. 

2009 and beyond  Recent FCC rule changes have again mandated that all new commercial radio systems be capable of a newer "narrow band modulation" and many high-end radios are now entering ham service as low-cost surplus.  Luckily, the established commercial bands are adjacent to 10M, 6M, 2M, 70cm and even 900 MHz.  Many well known brand names are showing up as surplus and the list now includes Motorola, GE/MA-Com, Kenwood Commercial Land Mobile, and others.   The events of the 1960's may be repeating themselves.

This is an example of only one cost-effective ham conversion, in this case an inexpensive 6-meter 110-Watt GE Delta which is the big brother to the GE Phoenix. This fifth generation family of GE radios  started to surface as surplus about ten years after their dominant commercial years. This is a favorite radio for high-performance mobile use on six-meters for many reasons:

very low cost when acquired as surplus equipment
 very high operational performance in terms of great audio and excellent receiver selectivity and sensitivity
high transmit power in most units
excellent propagation on 50 MHz, particularly in hilly areas
easy to convert to ham use

Previous FCC Rules prohibited business-band repeaters on low-band (just below 6M) requiring that most low-band commercial radios operated in simplex mode.  Due to that limitation, most mobile radios were manufactured with either 60 or 110-Watt  high-power transmitters.  If an enterprising ham can combine the excellent natural propagation of 50 MHz with high mobile transmit power and the utility of ham repeaters, the resulting performance can be without peer.

This is the most basic GE Delta S600 control head (tiny too!).  The switch modification on the side provides for two groups of 8 channels for a total of 16.

This fancy 99 channel, GE S950 or S990 Delta control head can download sub-groups of frequency/scan data into the synthesized Delta radio below. The Delta radios change their major option packages by simply changing control heads.  The radio RF drawer remains the same because the radio's personality is dictated by control head.  Much like traditional ham gear, many radios can be programmed with a PC although these radios may require a few extra steps.  This deluxe version control head goes for about $35 on eBay.

This resurrected 32ch, 110-Watt GE Delta was reprogrammed for use on 6-meters but variants are also available for the 10M, 2m and 440 ham bands.  Depending upon the model, little or no RF conversion or tuning may be required to reach the adjacent ham bands. The operational performance of these commercial radios often far exceeds that of the typical off-the-shelf multi-use, multi-band ham radio.  These high-power, synthesized workhorse radios originally sold for between $1500 and $3500.  GE Deltas can be obtained on eBay as surplus for approximately $35-$75 and sometimes come complete with cables and a basic S600 control head.  Depending upon what is available at the time, you may need to acquire the radio RF drawer, cables and control head separately. To some hams, if you know what to look for, "the hunt" is simply part of the fun but this is also where sharing knowledge through clubs can play a key role.

The final touch.

In a strange twist of fate, the commercial land-mobile market would no longer support these very expensive high-end radios and GE finally decided to exit from the land-mobile business.  Under the MA/Com name, Tyco now owns what remains of the former GE Land Mobile empire but that legacy is now a subset of what once was a dynasty. 

The GE Delta family was only used an as example of one easy-to-convert radio.  Many other commercial land-mobile manufacturers will soon see their relatively modern, high-performance radios re-enter ham service as bargain-priced, surplus gear.


Motorola MCS2000 for VHF/UHF/900 bands

Look for Motorola MAXTRAC, Spectra, Radius and SABER families to be available at very low prices and with very high performance.  Large quantities of surplus 900 MHz gear seems to be suddenly available with a matching growth in 900 MHz operations.

Here we are in 2009 and many hams who enjoy deploying this gear can be found joining together to swap manuals, expertise and parts. 

Hmmm... this sounds more like "classic" ham radio, doesn't it?


(c) 2009  Rick Zach, K1RJZ
k1rjz (at sine) komcast-dot-net


A cutting-edge two-way radio shop
with a MOTRAC on the bench... circa 1965.
Note the Bird wattmeter.  It never needs to change.


...and 2009.   (click the graphic)

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last revised 07/22/2009