RAN Technology

W9RAN Field Radio

Technical 0 Comments 05/11/2019 

Vintage light aircraft radios repurposed

Posted By: Robert Nickels (ranickels)

In the early days of aviation radio, transmissions originated from the ground using the longwave transmitter also used for homing,  and pilots acknowledged by wagging their wings.  It didn't take long to realize the benefits of having transmitting capability onboard the plane as well, and the first generation of aircraft radio used the low HF band.    Given today's crowded airspace it is hard to imagine every aircraft sharing the same frequency - 3105 kHz - to talk to the tower while still listening for replied on the longwave band.   For light aircraft, power output seldom exceeded a few watts, which with a fairly inefficient loaded longwire antenna meant a limited range, but that was sufficient.   Airlines and those flying longer distances drew power from a vibrator supply or even a dynamotor, but the most common setup used A and B batteries, just like some home radios still did, which were readily available.   

I acquired this near-mint set at the Cedar Rapids hamfest last summer.  The Ranger model 210 transmitter could put out 2 watts from it's battery pack power supply on either 3105 or by doubling, 6210 kHz which was the alternate frequency for daytime use.   The model 117 reciever also ran from batteries and tuned the radio range band, 200 to 400 kHz to hear transmissions from the tower, weather, and homing beacons.    A RAN Technology converter brings the 75 meter band down so the LF band receiver can be used as a tunable IF and a 5 watt audio amplifier provides loudspeaker volume instead of requring headphones.   Instant heating 1.5 volt battery tubes are used in both transmitter and receiver, along with a boost-type DC-DC converter to produce the 150 volts B+ instead of B batteries.  A previous owner had rewired the units for self-bias to eliminate the need for a C battery as originally required.    The battery pack would have  fit into a small box and carried onboard and replaced when necessary (hopefully before going dead during a flight!)    The transmitter uses a carbon microphone and is crystal controlled on 3885 kHz, with 2 watts output.  The normal airplane antenna would have been a longwire running to the tail with a loading coil resonator, but provision was made for a trailing wire antenna as well.   The receiver would have had it's own low-frequency antenna for flying the radio range and receiving the tower. 

I decided the pair would make a neat 75 meter AM Field Radio, and fitted them into a custom made plywood box that could be easily transported (to places like the Dayton Hamvention, for the WWII military radio net).   The removable lid has a 5" speaker and a storage compartment on the rear allows storage of the mic and Li-Ion battery pack.

Listen to a bit of K5UJ calling CQ as a receiving test:  Listen

The Ranger was an obscure manufacturer but big names including GE,  Lear,  Raytheon, Bendix, Philco,  RCA, and Motorola produced similar radios.   Most recognizable after WWII was the Aircraft Radio Corp., producers of the wartime "Command Sets".   A portable lightplane radio like this was often used when the ferry pilots (often women) flew the warbirds from the aircraft plant to a nearby base where the command sets and other radio equipment would be installed.   Having seen the RCA AVT-112/AVR-20 packaged in a wooden case for this purpose was the inspiration for making my own version.

I was fortunate to receive both manuals with my Rangers, but with a little effort the schematic and interconnections for most of these simpler aircraft radios can be figured out and it is a lot of fun to put such a cool piece of vintage radio equipment back on the air in a useful way.

   What can I say, I like oddball radios!    There was already a different version of this CAI CA-125 on my shelf but it had the remote control head, and this one was cheap, well under $100 including shipping, and I'm easily amused.   Communications Associates Inc. was a supplier of commercial, military, and marine radios based in Huntington Station, NY but I haven&#...  READ MORE
- Robert Nickels (ranickels),  05/14/2020 
   The HW-16 had to be pushed aside while waiting for parts, creating an opening just big enough for the homebrew receiver I got recently via eBay for $18.50 - plus 2X that to ship it here.   I like saving and restoring old homebrew gear just out of respect for the amount of time and effort our forefathers put into making things from scratch, and this receiver intrigued me, as the IF transf...  READ MORE
- Robert Nickels (ranickels),  04/28/2020 
    The Multi Elmac Company of Hazel Park and later, Oak Park MI is best know amongst hams for it's great mobile transmitters and receivers which were probably the most popular rigs of their type and are still often used on AM today.   The Multi Elmac Net pays tribute to these little rigs by and typically a half-dozen or more are heard on the net weekly.But the company's origin...  READ MORE
- Robert Nickels (ranickels),  04/22/2020 

Wireless on a Train

a lesser-known radio "first"
Category: Historic
WHEN Frederick Wally stepped out of a little cubby-hole in one corner of the forward day coach on the Lackawanna Limited, west-bound, as it neared North Scranton, Pennsylvania, Tuesday, November 25, 1913, and pinned a sheet of paper on the wall, the passengers in the front seats, who had been casually wondering what caused the strange, crackling sounds that had been coming from the cubby-hole, pri...  READ MORE
- Robert Nickels (ranickels),  04/14/2020 
    The  Dentron MLX-MINII thought it would be cool to use the Dentron MLX-MINI on the Saturday Vintage Sideband Net but it's a little marginal since the rule is "no tubes, go home!".   However hybrid rigs are allowed, and Special Dispensation is given for rigs with Red LEDs.    So I thought the MLX was double-qualifed - even more so after I realized t...  READ MORE
- Robert Nickels (ranickels),  04/04/2020 

AMECO - one of the forgotten ham manufacturers?

A company that was part of ham radio for over 50 years
Category: Vintage Ham Radio
The internet knows a lot about ham radio history, but not so much about a company that everyone recognizes:   The American Elecronic Company - AMECO.AMECO - American Electronics Co.; New York 53, N.Y (1950s).Manufacturer of HAM radio equipment.Also: AMECO - Division of Aerotron Inc., Raleigh, North Carolina (1968).Also: AMECO - Ameco Equipment Corp.; 178 Herricks Road Mineola, L.I. New Y...  READ MORE
- Robert Nickels (ranickels),  03/29/2020 

Mix and Match Radios

VERSA-TR makes it easy to play radio
Category: VERSA-TR Information
I like to play radio!   As a SWL and novice, I'd imagine owning different transmitters and receivers and now that I actually DO own many of them, it's fun to "mix and match" to put them on the air.     That's mainly why I developed the VERSA-TR, which is an RF-sensing T/R and muting switch, so I could easily change out transmitters and receivers ...  READ MORE
- Robert Nickels (ranickels),  03/07/2020 

An Unbreakable Code

Navajo Code Talkers in the battle for Iwo Jima
Category: Historic
The Code Talkers used native languages to send military messages before World War II. Choctaw, for example, was successfully used during World War I. But the Marine Corps needed an “unbreakable” code for its island-hopping campaign in the Pacific. Navajo, which was unwritten and known by few outside the tribe, seemed to fit the Corps’ requirements. Twenty-nine Navajos were recrui...  READ MORE
- Robert Nickels (ranickels),  03/06/2020 
   Faust Gonsett started the Sideband Engineers (SBE) company in 1962 and introduced their first product, the SB-33 four-band transceiver with a two-page ad in 73 magazine for February 1963 that featured his mugshot on the left page and the introductory ad for the SB-33 on the right.   He talks about how he came out of retirement to start this new company in response to many requests but do...  READ MORE
- Robert Nickels (ranickels),  02/15/2020 
   Well known radio repair guru and AM fan Jeff Covelli WA8SAJ of Cleveland OH wanted better receiving performance than his stock Nouveau 75 AM transceiver provided - and the VERSA-TR came to the rescue.  Jeff decided he preferred having the board mounted in an enclosure with connectors and the photos show his approach.    The VERSA-TR automatically switches the antenna from his S...  READ MORE
- Robert Nickels (ranickels),  02/11/2020 

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