UTILITY

UTILITY, PARAMILITARY and FORESTRY

High Frequency Radios

This page is somewhat of a catch-all for photos of assorted radios in my collection which didn't fit anywhere else and were difficult to categorize. Some of these also appear on my friend Klaus-Peter's greenradios.de web pages, where you can also see other examples along the same lines. These are presented in no particular order. Most are post-WWII although some were made in wartime as the descriptions will note. Note that for all intents and purposes, affordable production of custom made crystals in the United States in small quantity has come to an end. Therefore other methods such as DDS VFO kits or the W9RAN Epson oscillator modules represent alternatives, although as a result the receiver clarifier control will no longer function.

--Update-- It is my understanding that Epson has ceased making DIP packaged oscillator modules and now only offers SMD components, so this will require acquiring a small header adapter that you can solder the oscillator module to and have the necessary contacts brought out to solder pads or a male DIP pin header..

Another alternative is the "Prog Rock" by QRP Labs, a small circuit about the size of an HC-6/U crystal that you program via a USB cable. See the QRP Labs site here -----> ProgRock .

MOTOROLA SA 200 (CAI CA-32)

This is a 20 Watt PEP HF SSB radio capable of LSB, USB or CW, actually made by CAI (Communications Associates, Inc.) in New York for Motorola about 1970-73. Fully solid state, it is capable of being used as a battery operated portable, a mobile or a temporary base station. It has two crystal controlled channels and, somewhat surprisingly, no receiver incremental tuning (RIT.) Examples can be found with either CAI or Motorola labels. It was originally intended as an inexpensive radio for the UN peacekeeping forces in the Sinai in the 1960's. The original order was for approximately 1000 units but in the end over 30,000 were produced!

Because of the small original order, these radios were manufactured with old style point to point hand wiring and a few bare circuit boards fitted with eyelets, which were hand stuffed and then run through a wave soldering machine. But in the end, as above, over 30,000 were made! Where they all went is indeed a mystery. Made into frying pans throughout the Middle East?

CAI's main original business was tow boat communications on the inland waterways in the United States. When cellular telephone service became widely available, the customer base vanished. I had originally thought CAI had been absorbed by Motorola, but have been told this was not the case. CAI's principal owner was Don Mertan, K2AAA. CAI made a few other radios I will try to add in the future when I get decent photos, one being a rather large high power base station, all of which date from the same 1968-75 era more or less.

I was told by a former CAI employee that radios exiting the production line might have had either Motorola or CAI labeling (see photo below) put on as it left the plant. It is interesting that Motorola had a habit of disavowing knowledge of the existence of these sets - - I know this because at the time I asked them! . This one was used by the U.S. Bureau of Land Management (BLM,) and the other examples which have turned up have been from that source or the Bureau of Indian Affairs. I am unaware of any which might have turned up surplus in the Middle East.

The SA200 could have an optional antenna tuner, which clipped across the front of the set, apparently in lieu of the battery charger / AC power supply which this example has. Originally, there would have been a battery box which clipped across the rear panel of the radio. It was missing on this example. It can be seen that the microphone is the same as that used on the Motorola PT200/300/400 series of pack set VHF FM radios. I have never seen an example of the antenna tuner accessory, or the battery box either, but "hope springs eternal." Manuals were printed by both CAI and Motorola. For whatever good it does these days, the Motorola manual is Part No. 68P81057A20, April 1971.

Earliest models had different power connectors and featured a microphone gain control and a different metering switch arrangement. When using the battery power pack only, output power was reduced to just a couple of watts. This radio is more useful than others as it incorporates both USB and LSB, while many competitive radios from other makers offered just USB. In the "what were they thinking?" category, this radio uses an oven assembly to maintain crystal temperature. In portable operation, a good portion of your battery power is then being wasted heating the oven! Motorola was already using TCXO crystal oscillator assemblies in their VHF two-way radios, so why not in these?

The radio was placed in CW mode simply by plugging in the key, either USB or LSB was then selected. Motorola offered all sorts of accessories including a telegraph key. Most of these accessories today are about as rare as the Lost Treasure of Troy, so consider yourself lucky if you have any of them.

CAI CA-26A (Motorola SA 100)

This is another CAI product which can be found branded either CAI or Motorola, yet always featuring a Motorola Motrac style microphone, and dates from approximately 1966. One was featured in a 1966 (?) issue of Communications Equipment Marketing Magazine (CEM) showing a Motorola branded example installed under the dash of an automobile. As with the other CAI equipment, both CAI and Motorola printed manuals. One Motorola manual was Part. No. 68P81036A70-E, dated February, 1971, although these radios were in production by 1967.

A 100 Watt class SSB/AM/CW crystal controlled transceiver covering the usual HF spectrum of approximately 2-14 MHz, this example was originally used by the Army Corps of Engineers on the Mississippi River, as can be seen by their decal on the upper right of the front panel. It appears of earlier design than the CA-32 radio above, as it is a hybrid, containing both transistors in the receiver and 8298 (6146B) tubes in the transmitter power stage driven by a 12BY7A. The power supply is a separate item and is invariably missing when these are found. The power supply was usually a 12 Volt DC transistorized inverter although there was also an AC power supply. My example was obtained sans power supply. However, one of the 1960's Linear Systems mobile power supplies for equipment such as the Swan 350 would appear to work in this application, just as a Heath HP-23 or Swan 117XC AC supply probably would.

An interesting feature of this set is the vertical European slot-style "magic eye" tube to indicate modulation level on transmit. Also annoying, because if you need a replacement, good luck finding one today! Motorola advertised these in approximately 1967 or 1968 as a high power HF SSB mobile radio. It is unknown whether any customer was found other than the U.S. Government, and whether these were used in the Sinai as the SA 200 (above) was. Probably out of production by 1974.

CW operation was accomplished by using either the USB or LSB position. The transmit gain knob was adjusted with the key closed until the eye tube bars just closed. MCW would be accomplished by using the AM mode position after adjusting the transmit gain in the same way.

There are various modifications on these, involving added switches on the front panel. This one has a "squelch" switch; others have a "tone" switch. There were accessory phone patch (below) and selective calling adapters, the selective calling adapter was a much later addition and not made by CAI. This one was found on eBay some 22 years ago when prices were reasonable and shipping costs were not astronomical. It had the 1980 era selective tone calling decoder with it from an unrelated manufacturer. Note the transmit gain knob on the example below is incorrect; I have since remedied this. Note that the knobs are standard Motorola styles used on their Motrac equipment of the era.

Accessory phone patch SS-9:

KACHINA KC 100

Kachina, an Arizona company, was the first manufacturer to produce a computer controlled "black box" amateur radio transceiver, and they also made a number of paramilitary radios as well as a few utility type HF SSB sets. This is one of them, the KC 100, which I am told is basically a crystal controlled version of the Alda 103 amateur transceiver. It dates from the late 1970's to early 1980's. All the ones I have seen have been USB only, with a plug button in the mode switch hole. Kachina went out of the radio business in the late 1990's, leaving orphans such as this behind. They also made the models below, which are cosmetically quite refined compared the the 100, but not in the quantities of the KC 100, which seems to have been made in the highest quantity of any of the KC- series.

Kachina also offered a companion AC power supply for this radio. This item is best described as "scary." It turns out to be a 17.5 Volt (when unloaded,) unregulated power source. The only thing in it is a large transformer, two stud diodes, two huge electrolytic capacitors, and a large filter choke. No regulation, nothing else, not even a bleeder resistor! It seems to work fine in conjunction with this transceiver, but I would expect there to be tears before bedtime should you try to power anything else with it. I printed a label on mine which says "Warning - - unregulated 17.5 Volts!" and stuck it where some label had been at one time but fallen off. That one probably said the same thing.

All of these that I have seen have been surplus from the Civil Air Patrol, where they seem to be no longer NTIA type-accepted for use. I was told that some of these were seen in use by the Afghan government in the early 1970's, before the Soviet invasion. Where the Afghanis got them is yet another question.

KACHINA KC 101

The Kachina KC 101 was a departure from the simple style of the KC 100 and quite attractive. Note that most of the useful features were options and not installed here. The clarifier would have seemed a necessity. Note that the AC power supply was now built-in. It is believed that not many of these were made.

KACHINA KC 102 Photos of the 102 will be added when available, but I assure you, it's ugly !

KACHINA KC 103

The KC 103 is interesting as it has a tunable feature as well as being channelized. This was probably intended as a fixed base radio, considering the complicated nature of the controls compared to previous models. It is unknown whether this model ever saw actual large scale production. This example was on eBay in 2024,

KACHINA KC 104

This is the Kachina KC 104 "Nomad." It is not known whether this model ever reached production quantity either, but it was seen on eBay in June, 2024 with the seller stating that it had been his father's, who was a technician at Kachina. This is presumed to be near the last KC- series HF SSB radio except that a KC 105 has been seen, possibly a prototype. There appears to be a date code on a stud diode of the rear panel of 1996. No other information is known except as with the KC 103 above, these probably did not see large scale production.

DENTRON SCOUT

Dentron, the linear amplifier and antenna tuner manufacturer of the 1970's through early 1980's, tried manufacturing a number of HF SSB transceivers including the HF-200A, HF-200D, MLX-Mini, Horizon and Scout. All of these used the Japanese Mizuho SG-9 SSB generator board and except for the Scout, only made it to prototype or preliminary production.

The radios above (other than the HF-200A and D) were all made with leftover parts from the discontinued HF-200D transceiver of late 1981, which never saw production, and date from approximately 1982 to early 1983, although other than the Scout, they too never saw production.

The Scout was a radio intended for the Civil Air Patrol, which used frequencies in the 4500 kHz range, and was built into the surplus HF-ACS power supply cabinet, which was the intended power supply for the HF-200A and D model transceivers. The HF-ACS power supply had a regulated 13.8V DC output and also an unregulated 12.5-approximately 18 VDC unloaded output for the RF PA stages. Approximately 200 Scouts were sold, while an unknown quantity of packaged remaining units "disappeared" and wound up in a warehouse somewhere in Texas under what I am told were illicit circumstances after the company ceased business, with legal representatives of the company attempting to locate them in order to marshal the remaining assets. Those appear to have been gradually sold off one-at-a-time via someone using word of mouth and/or low circulation local classified advertising.

The Scout is an HF SSB 5 channel transceiver which as mentioned above, uses the basic circuit board from a Mizuho HF SSB radio (not that it's of much help to know that.) It appears that the filtering used on the output and possibly elsewhere is limited to the 4.5 MHz range, and therefore it will be necessary to modify this to run the equipment on the 40 Meter amateur band and possibly the 75 Meter band as well.

It is shown here with its companion HF-ACS AC power supply, in the same surplus cabinet, except with a different overlay at the front. My gripes about this radio are that it has no clarifier control (RIT,) and is USB only. On the other hand, it sounds great on the air with my junkbox 500 Ohm dynamic CB microphone. This one was yet another surplus item from the California area Civil Air Patrol, and it still has their 4 MHz western regional calling frequency in it. It appears that no manual was ever printed for them. If you have ever seen a manual, or have one, let me know. I would like to share a scan of it here.

My thinking is that it would be possible to remove the speaker from the Scout and place a DDS VFO in its place, removing the speaker grille and replacing it with a flat plate to mount the VF) display and controls. The speaker would then be located in the HF-ACS power supply.

SOUTHCOM INTERNATIONAL SC-100 and SC-102

Southcom International was a southern California firm that made a line of paramilitary HF SSB radios including man pack sets, and also these two base station tabletop transmitter-receivers probably intended for long distance business and government use, such as logging and forestry. Southcom was acquired by Loral and then L3 and eventually disappeared. I was told that Southcom was founded by Les Earnshaw, originally of Swan, Atlas and later Kachina Communications. There are several other Southcom HF SSB radios, paramilitary style portables, however these pages are not yet all-inclusive.

SC-100

The SC-100 is a simple single channel unit normally sold with USB only. The hole in the panel of this example would be where the clarifier control would have been. Why someone removed it is a subject best left to the lynch mob, but probably to vex people such as myself. This set uses a pair of 6HF5's in the RF PA stage.

SC-102 THUNDERBIRD

The SC-102 was a later product which had the advantage of 4 channels and selectable sidebands. The 102 uses a pair of 8928 tubes in the PA, which appear to be an industrialized version of the 6HF5 television sweep tube. The only other equipment known to use the 8928 is an HF SSB radio made by the Northern Radio Co. of Seattle. I was told that the SC-102 was made for a government contract but was rejected because it used a sweep tube PA section, and the examples produced then went to the Civil Air Patrol. All the examples I have found had CAP crystals in them. Fortunately this is one of the easiest radios to obtain a manual for - - Vintage Manuals sold bound photocopies before they went out of business and there should be copies out there. Otherwise, fortunately Manual Man (look him up on the web) sells copies. Note that only the transmitter requires alignment; the receiver is "plug and play" and one just inserts the correct crystal. Another unique feature is that this is one of the few utility radios with a telegraph key jack. These are often passed by at swap meets because they look like a CB radio base station, but have been somewhat common at California events in the "under $ 25" category.

RCE TR-4B (Canada)

This is the Radio Communications Equipment Co. TR-4B, a Canadian portable AM transmitter-receiver made in Montreal, Canada, probably for forestry or oil / mining companies in the wilderness and this may be one of only a few left.. The capsules inside the handset are dated 1957. It uses all miniature 1 Volt battery tubes and has room inside for several 45 Volt B batteries and apparently two # 6 cylindrical dry cells. There is no push to talk switch on the handset, one must use the front panel transmit-receive switch. There are still crystals in it for a 5.1 MHz frequency. I have never seen another of these; this was obtained through the kindness of friend Rick, W6NIR, a fellow forestry radio collector.

HUMBLE P-12 (Model B)

This is a Canadian portable forestry radio from the early 1950's made by Humble. Also used by assorted utility users such as logging and trapping. I have a separate web page for this radio, look here:

http://www.wb6nvh.com/Humble/Humble.htm

SPILSBURY SBX-61 Base Station

This is a solid state HF SSB base station made in Canada by Spilsbury and Tindall , probably in the 1970's. It has 12 crystal controlled channels, however each channel requires a set of a surprising number of frequency band range determining plug-in modules, and this example only has a single set. Obtaining additional sets seems quite impossible other than by fabricating them. This transmitter-receiver is USB or AM only. It is relatively lightweight and runs from 117V AC. Spilsbury made several portable HF transmitter-receivers in the 1960', such as the PRT-20, and I have the manuals and some paperwork scanned over on my "Misc. Data, Conversion Articles..." web page found on the main index.

Spilsbury was out of business by the mid-1990's, I think absorbed by another firm. They also made a couple of VHF FM fully solid state mobile radios in the 1980's, including a small solid state IMTS car telephone for Bell System use.

MYSTERY HF PORTABLE - Recognize it?

This set is an all vacuum tube single channel AM portable transceiver which has no maker's name on it that I have been able to find. Why would the manufacturer not leave their name anywhere? That leaves out Morrow and Radio Specialty which always engraved their name on equipment somewhere. If you recognize this radio, please tell me!

The marking of the parts suggests this was made in the USA in the early or mid 1960's. The telephone handset carbon microphone capsule is dated January, 1967. It has a neat self-contained telescopic antenna rod that doubles as a handle when unplugged, and a loading coil assembly that stows inside the handset area. This is crystal controlled on a single 5 MHz channel. The bottom area is reserved for a number of A and B type dry cell batteries. If the receiver were tunable it would be an ideal candidate for 75 Meter use! This was very possibly not a forestry radio at all, it may have been made for some entirely unrelated government agency . It is still tuned on 5422.5 kHz, which seems to have been, or still is, a US Coast Guard coordination channel. Unlike most other utility radios, is has full transmitter tuning and loading controls on the front panel and instructions to the user on a placard in the lid.

FISHER RESEARCH LABORATORY RS-25 / TS-25

This is a high frequency AM receiver-transmitter made during World War II primarily for military police and military fire engine use. All octal tubes. Eventually it was given a standard military type number, late in wartime or early thereafter, of AN / VRC-4. Fisher Research was a Palo Alto company that later would make personal marine radios and metal detectors. They are still in business as far as I know, but have moved out of Palo Alto and do not make radios anymore. Most of these were black but the military example below is gray. The receiver is interesting in that in addition to crystal controlled channels there is one screwdriver-tunable channel as well (tuned from the inside in advance.) There were multiple types of power supplies. There are a handful of these still in existence among the radio collector community.

My set of these came from one of the Northern California ham radio swap meets in the mid 1990's (Livermore, I think) and was new old stock with the paper still wrapped on it. BUT...the resident cat greeted me when I arrived home with my flea market wares, and became very insistent that I get the Fisher transmitter opened up immediately. So I did, and found that it had been infested with mice, and there was dried mouse urine and droppings everywhere as well as a nest and a couple mummified dead occupants, but no live ones. After having a quick look, the cat made a face of disgust and walked away, evidently thinking "Stupid human, paid good money for another metal box with dead mice in it and didn't even know that when he bought it..."

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