Tuesday, October 8, 2019

MilCom

First of all, "My Bad!" It has been months since I have blogged anything and I must apologize to the readers of this blog. I have three other entries in draft and will get this posted ASAP.

Over the years I have collected, restored, used and sold a lot of old military communications (MilCom) equipment. It started when I was in high school when a family friend gave me a beat up BC-1000, low band FM squad radio circa WWII.

That led to a slew of old ARC-5/Command Sets (mainly receivers) and the occasional piece of test gear. My 20 year career in the USAF allowed me to "play" with a lot of comm gear but due to constantly moving around the world precluded my obtaining any surplus gear. 

The one exception was when I was assigned to the 1936 Comm Squadron in Lajes Field, the Azores. The folks at AFR&M surplussed out a bunch of old Motorola base stations in the low band and high band VHF freqs. I purchased a L43GGV high band radio that I (along with several others) converted over to 2M FM....146.94 simplex and 146.34/94 repeater frequency. 

Once I was transferred to the 3rd Mobile Combat Comm Gp (3rd MOB) at Tinker AFB, OK (right outside Oklahoma City) I became active on the local 34/94 machine with my 20 year old Motorola rig. Thank you Uncle Sam.

Once I retired from the AF in 1987, I found that MilCom gear tended to follow me home from various ham radio flea markets. Prior to moving from PA to GA I had a basement full of military comm gear, most of which I realized that I was never going to restore much less use. Therefore, I sold off about 90% of my MilCom gear. 

A couple of Command receivers, a BC-221 frequency meter, a GRR-5 SW receiver, and my favorite: a PRC-74B HF synthesized SSB/CW transceiver followed  us down to GA. Within a couple of years those were also sold off due to the need to get some liquid funds after our move. 

The PRC-74B (also called a "74 Bravo") was my retirement present to myself. Mark Francis, KI0PF, built this radio up from spares that he had accumulated and installed the LSB mod to allow both USB/LSB operation. Designed and built by Harris Corporation, the 74 Bravo was the first fully synthesized HF radio to see service in military ground forces. Used primarily by the Army Special Forces (Green Berets) in Vietnam, this provided the special ops folks in country with reliable HF communications. I really hated to sell that set as it had special significance for me but hey, when the wolf is at the door.....

Slowly (very slowly, actually) I began obtaining the occasional small piece of MilCom gear. One of my all time favorite low band VHF FM squad radios is the PRC-1088 manufactured by Datron. Originally Rockwell Collins designed and produced this man-pack radio set to enter the completion to replace the venerable PRC-77 from the Vietnam era. Unfortunately the military declined the Collins radio in favor of SINGARS. Rights to produce this radio were sold to Datron which still produces it today. It is a nice FM unit with a digital readout that can frequency hop while offering an optional encryption package for secure voice communications. Mine hops but cannot go secure. The overall package is the same form factor as the PRC-25/77 and uses the same mics, speakers, and headsets. The antenna connector is a BNC type unlike the PRC-25/77 radios. It offers low power output of around 300 mW and a high power output of around 7W. 

During a recent flea market run my wife, Patricia, (KB3MCT) and I found an estate sale that included a large amount of MilCom gear that covered WWII to Vietnam. I was too late to pick up one of the two PRC-74s, but was able to score four Command receivers covering from 100 kc to 9 mc. Three of these receivers were installed in a triple receiver rack and included the remote tuning and audio units and all the proper wiring. Unfortunately no splined tuning shafts but all the receivers had tuning knobs in stalled so it was no biggie. 

One BC-312 WWII HF receiver followed me home along with two PRC-127 hand held low band FM units theoretically used in the first Gulf War. They worked, too!! 

The US Army Special Forces during the Vietnam era needed a portable low power HF set to provide intermediate range comms in the jungle. Sylvania was chosen to design and field such a radio and the AN/TRC-77 was born. This luggable radio set. while it was portable, was not able to be operated in a man-pack configuration and therefore was given the TRC (Transportable Radio Communications) nomenclature as opposed to the PRC (Portable Radio Communications). The 77 was a CW only (on transmit, CW/SSB/AM on receive), six channel crystal controlled package about the same form factor as the PRC-25/77. It was tested over a period during the early 1960s but was not adopted by the Army for use in Vietnam. However, the LRRP (Long Range Recon Patrol) units in Europe utilized this radio for HF comms finding it fitting their needs as long as the operator was a good CW op. Operation is ultra simple, the six channels can be independently selected and a set of "cans" and a key (antenna not withstanding) are all that is needed to get on the air. 

The TRC-77 soon became the 77A with some minor internal and external changes. But in essence it was the same radio, same size and still very easy to operate. Those of us who like to obtain, restore and use MilCom gear find the 77A a great little rig with a price tag that is fairly easy to swallow. Mine cost $200 with no crystals. 

Crystalling up one of these radios is expensive today. With the demise of International Crystal Manufacturing (ICM) there are only a couple of crystal providers and their prices START at $50/each, depending upon the type!  However, there is a work around. Digi-Key carries a series of crystal oscillator ICs that are extremely stable and come in 8 pin DIP through-hole components. Hayseed Hamfest offers a four-IC PC board in kit form that will provide four independent oscillator outputs that can be used in older radios. This board seems a bit large for inclusion inside the 77A but the idea of using these programmable IC oscillators to replace crystals in older radios has merit. Besides, it a whole log cheaper! 

There are also options to rock up the transmit side of the 77A using HC-49 crystals (with leads) obtainable from QRP.ME and
expandedspectrumsystems.com. Prices are very inexpensive and these crystals can be directly soldered to the underside of the transmitter crystal bank and they will work quite well. (See N6CC.com for details on all this crystal stuff.) 

The receive crystals are 455 kc ABOVE the transmit frequency which makes it basically impossible to use QRP HC-49 crystals for the receiver. This is where the programmable IC oscillators will shine. Again, consult N6CC's website for intimate details. Tim has done a lot of the heavy lifting on a number of MilCom restorations and modifications so he speaks from first hand experience. 

I am going to detail the restoration of my 77A in this blog, hopefully spiking some interest in others to quit building "cute" little single band kit CW rigs and move onto some REAL radio!!! 

Vy 73

Rich K7SZ














Sunday, May 5, 2019

A Tale of Two Radios

"It was the best of times, it was the worst of times" 
(with apologies to Charles Dickens) 


Anyone who has been in this hobby for any length of time realizes they need (want?) more than one radio. It's a disease. Trust me. 

ONE do-all radio (FT-817/818/857) is a great idea.....until.....it breaks. What now, coach? 

The solution is simple, have a standby radio to pick up the slack while the primary radio undergoes maintenance. Makes sense, doesn't it?  It makes real sense when we talk about emergency communications (EmComm) or for the "preppers" out there trying to bullet-proof their communications systems.

For the last um-teen years those of us who have participated in Amateur Radio Emergency Service (ARES) have used analog VHF FM to pass emergency traffic. Over the last few years digital modes like PSK-31, WinLink, DStar, etc have been incorporated into the EmComm arsenal much to the consternation of many of the Old Guard within the EmComm community.  

Gradually VHF gave way to a combination of VHF and UHF FM modes to spread the wealth around allowing more communications channels with which to improve redundancy and to support the mitigation of the emergency. This idea was something that had come of age owing to the proliferation of V/UHF dual band mobile and hand held transceivers (HTs). These devices allowed the EmComm/prepper user to have access to more spectrum which is always a great idea. 

 When it comes to survivable/emergency communications it might be a good idea to pay attention to an adage used by "preppers/survivalists": Two is one and One is none. Ergo, if you have two radios and one goes Tango Uniform, you will still have the ability to communicate. I like that adage, actually. 

One of our local area amateur radio clubs has an EmComm trailer that has all sorts of comm gear installed: HF, V/UHF FM, CB (yes, one of those "10-4 good buddy rigs") along with a portable repeater. A high end computer system, and of course, antennas to match all those radios plus gas generated power. Great idea, especially when it has air conditioning!!! Unfortunately only the "chosen ones" within that particular ARES organization have the privilege of manning it. Alas, once again "the great unwashed" are left out in the cold but it does look good on display at ham fests and field day.

Recently Patti and I were able to afford a covered Horton Hauler 6 x 12 foot utility trailer. The previous owner was an elderly locksmith and used the trailer for his business while on the road. It came with 120VAC and 12VDC lighting and power factory installed, along with a counter weighted rear door and a host of other options. The price was an absolute steal  so we jumped while the jumping was good.  

We are going to remove some of the cabinets and stowage that was previously installed and add a communications console, workbench and basically convert it over to our camping/mobile ham shack trailer. While we have a nice 25 ft fully outfitted camping trailer this smaller trailer will fulfill our needs much better than it's bigger cousin.

As to radio gear I plan on installing a HF SSB/CW/DATA radio along with V/UHF analog/digital radios, two high end scanning receivers, a CB set and a high power GMRS transceiver along with a couple of recycled laptop computers. I will have enough redundancy in place to continue operating should one or more of the primary radios fail.

Plans for this camp trailer/ham shack include outings to local county and state parks, speed runs up north to visit the kids/grand kids, Field Day, Winter Field Day, and the occasional camping/fishing trip.

In short being able to continue to operate should one of the radios go down is a great proactive idea. Provided I can find one additional Icom IC-2720 dual band V/UHF FM radio I will install that radio in the trailer as I have that particular rig in both my Chevy Silverado and Patti's Chev Equinox, giving me the necessary redundancy on those bands. 

Backtracking a bit, the addition of two scanning receivers gives us the ability to monitor local and state radio systems for the emergency responders. 

Time for a "War Story": about 15 years ago I was working at a state prison in NE Pennsylvania. One evening I heard a gaggle of sirens across town and turned up the gain on the scanner beside my chair. The local Wilkes-Barre PD and the Luzerne County Sheriff  frequencies were going wild with urgent traffic. 

It seems that two of the "guests" of the county jail had engineered a daring escape using bed sheets to form a makeshift rope that they used to slither down from their cell window and escape into the community. 

Since I knew the State Police air unit would be involved along with local township law enforcement units I put two more scanners on line and was monitoring the frantic action in trying to recapture these two miscreants. 

Suffice it to say that these three scanning receivers allowed me to keep up with the exciting, non-stop action happening only several blocks away from my home! There is little doubt in my mind that I knew as much, possibly more, about the efforts to recapture the two escapees than the on-scene incident commander! 

As to the inclusion of CB and GMRS radios that is a no-brainer. There are several million CB sets out there and probably triple that in GMRS rigs. Being able to gather information (intelligence) from these valuable sources can provide valuable insight to local situations. 

So now all we have to do is get the time and allot the energy to upgrading the new trailer. The antennas needed to support all these radios will be a challenge since at first glance, the outside of the trailer is aluminum and mag mount antennas won't stick!! That is OK, we'll think of something! 

Now how will I mount that V/UHF beam array??? Hmmmm.....

Vy 73
Rich K7SZ




















Sunday, January 20, 2019

What Once Was Old is New Again

Radios, radios, radios.....I love radios. Over the years I have owned more than my share of boatanchors, QRP rigs, V/UHF gear, short wave (now called "world band") radios, some CB rigs and, yes, a scanner or two. 

For one reason or another I have sold/traded most of that gear off and have kept only a very select group of radio equipment. Herein lies the crux of this blog. "The one that got away".

In 2017 I managed to afford a brand new Elecraft KX2 ultra-portable HF transceiver. The KX2 is an utterly fascinating radio, it's size being deceptively small for all the features that are packed inside that tiny box. I was very proud of my new KX2 and took it to Grand Forks AFB, ND when Pat (KB3MCT) and I visited our grand daughter and her hubby after the birth of Eloise, our 3rd great grand child. I had a simple vertical antenna set up on the back yard of their base house (complete with three radials) and made a grand total of 3 Qs over a 4 week period. Not a stellar number of contacts given the extended period of time. 

That experience sealed the fate of my KX2. I quickly found that although I liked the rig a lot and it was a small miracle of miniaturization and design it was NOT a fun rig for me to operate. Don't get it twisted, I was very happy with the radio but several things about it's operation started to bug me. Soon, I knew that I had to find it a new home and get a replacement. One that had a lot of features, was well respected in QRP circles and one that I was at ease operating. 

Enter the Elecraft K2....."The One That Got Away!" I built my first K2 back before the turn of the century. It was loaded up with all the options Elecraft sold except for the 100W linear amp....(I don't need no stinkin' 100 watts!) and I loved it. The building experience was not only pleasant it was also very soothing and calming. Pat worked nights as an armed Social Security Guard at the data center in Plains, PA, so I would stay up very late each night and Conan O'brian and I would build the K2 together. Occasionally I'd tune to Coast to Coast AM with John Noory and listen to all the UFO/conspiracy theorists explain how the space aliens had taken over MacDonald's and were fattening up Americans to become a food source for their dying planet. WOW! 

My original K2 and all the options went together without a hitch thanks to the extremely well written instructions provided in the K2 manual (thanks Wayne and Eric!) I used that K2 until 2005, when I sold it to procure a newer, more expensive piece of gear. Dumbest move I ever made (not including marrying my first wife). I have regretted that decision countless times over the intervening years. Time to find someone that wanted to off load their K2 in exchange for my KX2.

I placed an email on the North Georgia (NoGA) QRP Club reflector and within 24 hours Pickett Cummins, AD4S, emailed me back saying he had acquired a K2 from the estate of a local QRPer who had just become a Silent Key (SK), would I be interested? I immediately told Pickett that I was most assuredly interested and maybe we could do a trade.

We exchanged several emails and last Thursday I traveled to AD4S' QTH to seal the deal. He liked my KX2 and I definitely liked the K2 he was offering in trade. The K2 looked near mint. It was a bare bones CW rig with only the KAT2 internal automatic antenna tuner (ATU) installed. We struck a deal and I walked (stumbled?) out his basement door with my new K2 under my arm. 

Presently there is the KSB2 SSB option and the KAF2 active audio filter option on order as well as a factory manual. I need to find a copy of Fred Cady's, KE7X, book on the K2 which is long out of print. The hunt is on. 

Over the next 11 months I am going to procure the KNB2 noise blanker, the KIO2 I/O option, along with the K1602, 160M/2nd antenna option. Elecraft has discontinued their KDSP2 digital signal processor option apparently from either poor sales or the lack of availability of critical through-hole parts. This last thing weighs heavily on my mind as it is possible that Elecraft may decided to discontinue (retire?) the K2 and it's options, in the near future due to this parts procurement problem. I certainly hope not as the K2 is a great kit radio and it offers QRPers the chance to construct a world class HF rig that, although 20 years old, still performs admirably on today's bands. 20 year old technology be damned, it is more radio than I'll ever need given my current operating schedule/practices. 

One thing I loved about my original K2 was it's ease of operation. Once the learning curve had been mastered it became second nature to tweak controls to optimize the radio. Controls were ergonomic and easily accessed without going through 4 or 5 nested menus. Something I really liked! In short, the K2 was, and still is, a viable HF multi-mode station even by today's standards. Additionally, the K2 set the bar for future HF rigs, including those offered by the Offshore Empire. I have said it before, Elecraft, and it's amazing and talented engineering talent, have revolutionized ham radio equipment design, forcing other manufacturers to up their game to stay competitive. All this done by a hand full of people in northern California. Well done, Elecraft!

So I have managed to recapture "The One That Got Away" and am looking forward to many years of flawless operation on the HF bands with the K2. 

Time to go ogle the new K2 and maybe even put it on the air!

vy 73
Rich K7SZ
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