Using Military Surplus Radio Gear on Commercial Fishing Boats


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Musings about fishing in the 60s and 70s.

LP 21 LM ADF loop which was mounted on the roof of the wheelhouse.  If I put my ear to the ceiling I could hear it running, its 400 cps servo motor furiously hunting for a null as the boat yawed in heavy seas


Mark Meltzer (AF6IM)  in the wheelhouse of the fishing vessel Josie M circa 1972.


FV Night  Wind owned and skippered by my good friend Stan Davis.  Its home port is Bodega Bay CA. Our fathers were both commercial fishermen. Stan and I went to U.C Hastings Law School together. We earned our way through school fishing salmon and tuna during the summer breaks while our classmates were working as law clerks.  I think we had the better jobs, by far. We both passed the CA bar exam on our first try, but Stan preferred a life at sea to a desk job and kept fishing. Even today he is at sea fishing for Albacore tuna a few hundred miles off the NW Pacific coast.  He has fished the Night Wind all over the Pacific including Midway Island, Samoa and Tahiti. The Night Wind was the last boat built by Martin Allen, of Moss Landing CA. She's a real beauty to my eye, powered by a single KT 19 Cummins diesel and LOADED with radios.

The black and white photo of me above the Night Wind picture was taken around 1972. I was an EE student at UC Berkeley (could you guess from the hair?) and skippering commercial fishing boats during the summer. My Dad, Ted, was a commercial fisherman and I learned the trade from him starting at age 11 as a deck hand and working my way up to captain at age 17. One of the best summers I ever had was in the mid 60's when I was skippering a leased boat with my brother Nick as the first mate and my Dad was fishing his boat with my brother Tony aboard. We were coastal nomads, fishing our way up and down the rugged north coast of California catching King Salmon (Chinook) which were plentiful that year. Fuel was cheap and the wholesale salmon prices were high. Life was good, really good.


I was very close to my Dad and treasure the times we spent together on the water, making a living fishing. He taught me a lot about hard work, ethics, kindness, compassion and how to get along with people. He was a gentle man but he had a tough side too. He had been homeless during the Great Depression and was rescued by President Roosevelt's CCC (Civilian Conservation Corps) which gave him a job, three meals a day, new clothes and a very modest paycheck. There were sometimes fights among the CCC workers and you had to know how to take care of yourself.  My Dad learned how to fight there. The CCC crews built dams, trails, roads and all sorts of infrastructure projects. Work programs like the CCC always seemed a lot more productive to my Dad (who was a left leaning liberal) than a welfare system that teaches no skills to recipients and gets nothing back. My Dad taught me and my brothers how to fight, but warned us sternly never ever to start one. My pacifist mother was appalled when my Dad set up a makeshift boxing ring in our back yard and recruited a pal who was a former Golden Gloves champ to spar with us and teach us the basics of self defense. My father died in 1978. I miss him every single day.


I was totally fascinated by radio since I was a little kid but actually began to understand it as a teenager.  Surplus radio gear gear was still plentiful in the 60s and inexpensive. I took full advantage of the situation to put cheap but very well built military radio gear on fishing boats. Note the C4 ARN 7 Radio Compass (ADF) control box in the background and the I 82 selsyn azimuth indicator ceiling mounted. The card stuck into to the top of the I 82 listed the marine radio beacons in the Northern CA area. It was printed on the back of Cal Marine Radio business cards, a local radio repair shop. The NDB (non directional beacon) I used most was the powerful beacon on the Farallon Islands, 318 kc and transmitted F .._. in MCW Morse Code. Many points and lighthouses had beacons in the 200-400 kc range including Pt. Bonita, Pt. Reyes, Pt. Arena and others. I don't think there are any USCG radiobeacons operating today with the exception of RACON radar transponders that operate in the X (microwave) band.


We had no radar at that time (too expensive) and used the ADF for primary navigation until I found a cheap APN 9 LORAN A set and put that aboard. The APN 9 was a vacuum tube unit and required a lot of skill to operate. There were no digital counters, just crystal oscillator generated  timing marker vertical  "pips" on the CRT that you had to manually count after you had aligned the master and slave signal waveforms. It was easy to confuse a skywave for a ground wave signal and you had to look at the screen very carefully to avoid mistakes. The delay between the master and slave reception (measured in microseconds) gave you a hyperbolic line of position. You needed two intersecting LOPs to get a position fix, but in a pinch you could use one LOP and a sonar depth reading to give you a rough fix.
I wanted to put an APS 20 S band aircraft radar on my Dad's boat but he nixed it, saying it was too big. There was a complete new crated APS 20 available dirt cheap in a warehouse in Oakland. They guy who owned it wanted to get rid of it and a couple of hundred dollars would have sealed the deal. The APS 20 had a full 360 degree scan and I was fiercely determined to get it installed on my Dad's boat. The APS 20 was way over my head technically, but the military TO (tech order) maintenance manuals were so well written and complete that I was certain that I could get it wired up, operating and even successfully troubleshoot and repair it if it had problems. Those manuals were beautifully put together with pictures, diagrams photos and very clear writing. I begged my Dad, pleaded with him but he would not give in. He was probably wise to veto the APS 20. Some tuna boats from San Diego used other types of surplus aircraft radars and they always had problems with them. The ones I saw on tuna boats only scanned a fairly narrow pie wedge sector straight ahead (not 360 degrees like marine radars and the APS 20) and weren’t really designed for the corrosive marine environment. The surplus aircraft  radars were power hogs and also suffered from HV arcing and other problems. Still, every time we groped our way through zero zero fog praying for the best, hoping that that we wouldn't get run down by big freighters, I imagined how sweet it would have been to have the big APS 20 showing the way on its 360 degree PPI scan CRT. Amazingly the WW 2 vacuum tube  APS 20 search radar soldiered on into the 1990s aboard RAF Shackleton AEW planes in the UK. No DSP, no diisplay symbology, no solid state components except a detector diode. This had to be the last WW 2 electronic gear to see active duty military service.


Manual RDFs were really hard to use accurately on a boat that was often yawing pitching and rolling. I longed for an ADF and an abundance of cheap surplus ARN 7 gear allowed me to get one dirt cheap. I liked ADF navigation and used it to full advantage. There was an AM broadcast station in Ft Bragg CA with a tower sited right on the coast that gave a very sharp null which enabled me to always find the Noyo River entrance buoy even in pea soup fog. I'd start in slightly deeper water to avoid trouble, find the correct DF bearing that you'd see from the buoy and then ride the bearing into the charted depth that the buoy was anchored in. Bingo every single time even in nearly zero visibility. The loop compensator allowed you to zero out nearly all bearing distortion from the boats extensive metal commercial fishing rigging. It took some work to calibrate it properly but when set up right it worked like a charm. It was a brilliant design using a circular spring steel strip cam that you could vary the shape of with circumferentially spaced adjustment screws. The cam follower drove the loop selsyn and gave you corrected bearings on the I 82 indicator,


I bought the R5A ARN 7 receiver from "Crazy Abe" at Standard Surplus on Market Street's Radio Row in SF for $25. The service tag indicated that it had been installed on a C 47.  Abe was a real character, with an explosive temper, but he liked me and always treated me well. Abe gave me full access to his treasure trove basement where I found a pile of foil wrapped R5A ARN 7 receivers. Abe also gave me good price breaks because I was a kid. He'd say "fifty bucks" in a loud gruff voice, pause and then lower it and say "but for you kid, twenty five."  I bought the LP 21LM loop antenna  (freshly OHd with a yellow tag) for $25 from George Bello, a surplus dealer in Oakland CA. The rest of the stuff came from Fair Radio in Lima Ohio and other more obscure sources: plugs, tuning shaft etc. The hardest thing to find was the back plate mounting for the C4 control head, as they usually stayed with the plane when they were scrapped. I just found one last year at a local ham radio flea market and bought it to keep as a spare. Back in the 60s I just couldn't find a cheap ARN 7 manual so reluctantly I sent $35 to a company in Florida, and got a brand new original military ARN 7 tech manual by return mail. Interestingly, it had a post war mimeographed insert with detailed instructions on how to convert an ARN 7 into an FAA approved MN 62 ADF. The ARN 7 to MN 62 morph mostly involved connector changes.
I built my own 12 VDC to 110 VAC 400 cps solid state inverter good for about 350 watts. The square waves made the ARN 7 selsyns screech, but they worked fine. The inverter worked  with the APN 9 LORAN A set too. My home brew inverter didn't produce much RFI but it was surprisingly noisy acoustically. I suppose the noise was coming from the transformer cores ringing at 400 cps. It was quite loud actually. I measured the inverter's efficiency and it was about 85%, not too shabby for a junkbox project where components were selected more by price than meeting specs.


I modified the oscillator coil on band 4 of the R5A ARN 7 receiver to enable it to tune the 2-3 MHz AM marine band. I got the idea from examining BC 433 rcvrs which were commercially modified to tune that band and marketed to fishing boats completely set up for shooting DF bearings on other boats while they talked. My ARN 7 paid for itself many times over by shooting bearings on boats that were catching fish. Sometimes they were communicating on "secret channels" in the border between the 160 M ham band and the Marine Band at 2 MHz.  I later modified my ARN 7 ADF setup to steer the boat (like approach couplers on airplanes) rather than steer the loop. First I would use the manual loop control to position it so a null was dead ahead and then switch on my steering controller. It was a crude bang bang non proportional control system with relays that interfaced with my Wood Freeman Model 11 autopilot motor controller, but it worked fine. I could set it up to steer me to the Farallon Islands. The closer I got the better it worked as the null got sharper.


The box I am holding in the photo was the control head for a home brewed digital sonar signal analyzer that I designed and built to see if I could sort out fish species by their echo characteristics. It worked reasonably well on fish types that had large air bladders, but salmon do not, so if the salmon were deep it was of little use as the air bladder echo was too weak. It did pay off once in Drakes Bay, a shallow anchorage at Pt Reyes CA. I turned it on as I was pulling anchor in about four fathoms of water. I saw what looked like a salmon echo to me. I pulled the anchor and dropped a line over the side and immediately hooked a salmon that dressed out weighed 42 pounds. I bet it was 46 or 47 pounds before I gutted it. I trolled around for 20 min and caught nothing further so headed out to the deep water grounds where I could use my commercial gear.


There was a lot of surplus radio gear in the fishing fleet in the 60s, APN 9, APN 4, ARN 7, SCR 269, BC 375, BC 191, TCS, ARC 5 and ART 13 and others. Fishermen were always looking for "secret channels" for covert comms within their home fleet. All sorts of things were used ranging from re crystalled CBs and 2-3 MHz marine radios to converted taxicab VHF FM radios. The FCC fought it, but it was a losing battle as the boats were very mobile and never used the gear when in harbors. FCC inspectors would show up at the commercial fishing docks once in a while but they were usually refused permission to board. The FCC radio cops would threaten to return with US Marshals, but that was always an empty threat. The party boats (sport fishing charter boats) that carried passengers for hire did have to submit to FCC inspections as they had USCG mandatory radio installations. The party boats mostly avoided "secret radios" and pirate channel crystals because it was too easy to be caught. 


My Dad never wanted me to be a fisherman and was both proud and relieved when I pursued and completed a college degree in electrical engineering. He saw the end in sight for fishing with mounting regulations, depleting fish stocks and rising fuel prices. I have a great shore job now, but often long for the ocean life. It was so satisfying. It was dangerous too. My Dad and I lost good friends, some of whom were never found. It was eerie when a boat would be reported missing, no distress call, no indication of trouble, they just never came home. The sea sometimes keeps its secrets forever.


I am about five years from retirement and hope to commercial fish again when I retire. I doubt if I will make any serious money at it, but  I still have my license and active commercial salmon permit and look forward to living that satisfying life one more time. I'll no longer fish stormy weather and I'll have a lot more safety gear. I may even re-install the old ARN 7 which I still have. It will need some work (caps are now 67 years old) and it is pretty obsolete as a nav radio, but it will bring back good memories and there are still AM BC stations and LF aviation non directional beacons to shoot ADF bearings on.  I kept my promise to my Dad to get a college degree and a stable shore job. I bet he won't mind if I fish a bit in retirement. I'll bet he will be looking right over my shoulder with that big warm smile of his.
For more musings about my days as a commercial fisherman see:


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