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The Heathkit HW-30 “Twoer”

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The Heathkit HW-30 “Twoer” VintageTechnical Radio Johnby Mark Dilks, Spencer, K2TQN, WA8SME [email protected] The Heathkit HW-30 “Twoer” Harold Kramer, WJ1B, fondly remembers the “Benton Harbor Lunchbox.” If you were a Novice in the 1960s, the Heathkit “Twoer,” model HW-30, might be A downside of the design was familiar. It was a 5 W, 2 meter AM trans- that the super regen receiver ceiver — ideal for the produced a lot of RF noise that days when Novice am- Figure 1 — WJ1B’s got into the other receivers in ateurs were permitted Heathkit “Twoer.” It my shack. I installed a switch is still in reasonably on the back of my Twoer to to operate AM phone good shape after from 145 to 147 MHz. almost half a century. disable its receiver when it was Back then a bare- not in use. bones Twoer offered The transmitter was crystal an easy way to get on controlled. Most stations the air. It cost $44.95 operated between 145.2 and ($350 in today’s dol- 145.7 MHz and that required lars) and included a 8 MHz crystals. The standard 45 page manual and a FT-243 crystal socket was in- ceramic microphone. It conveniently located inside the was a kit, however case, so you had to remove the case 1 I did not build mine. I purchased my Twoer weighed only 6 ⁄2 pounds and was factory to change crystals. I relocated the crystal from one of my Elmers. I mowed a lot of configured for 110 V operation, although it socket to the rear of the case where it could lawns to earn the $35 that it cost! could also run on 6 or 12 V dc with Heath’s be reached easily. This was a very common Along with the Twoer, Heathkit sold other GP-11 external power supply. modification among Twoer owners. transceivers with similar features including Inside the Twoer’s Design The transmitter used a Pierce oscillator and the “Sixer” for 6 meters and the “Tener” for two 6BA8 tubes that tripled the 8 MHz 10 meters. The first ads for these radios ap- The Twoer had only peared in December 1960 issue of QST. five tubes (see Heathkit sold thousands of these radios Figure 2). It used a through the end of the decade. super regenerative receiver, a circuit I put my Twoer on the air in the late 1960s. popular in the 1920s At that time many of my teenage ham radio and early 1930s. The friends were active on 2 meters, but FM had receiver itself used yet to catch on. Using 2 meter AM I could half of a 6BS8 triode work local hams, participate in local Civil and was plenty sensi- Defense activities; (CD was the predecessor tive, particularly since to Homeland Security) and join The Con- the other half of the 6BS8 necticut Mobileers, an early Emergency was an RF preamp. Communications group. With some luck Heath claimed the sensi- and a decent antenna, you could work sta- tivity was “as low as one tions a few hundred miles away when the microvolt at the antenna ter- band opened. minals.” Receive sensitivity was set with a “Regeneration” The Twoer was nicknamed the “Benton pot on the back of the trans - Harbor Lunchbox” because Heath Company ceiver. was located in Benton Harbor, Michigan and it actually looked like a lunchbox with Selectivity was not the receiver’s its metallic beige case, boxy shape and its strong point and separating signals handle on the top (see Figure 1). There was was a problem. This did, however, make even a handy slot on the side of the case to it easy to listen for other stations since hold a copy of your license. The front panel you could set the tuning knob midway be- had only three controls: On/Off /Volume; tween 144 and 146 MHz and hear just Figure 2 — An Tuning; and Transmit/Receive — with about any signal on that portion of the inside view of both PTT and lock positions on transmit. It band. the Twoer. 96 June 2013 ARRL, the national association for Amateur Radio® www.arrl.org to 145.40 for a call.” You used this method so you would not miss stations calling you on dif- ferent frequencies. My most memorable experience with the Twoer was when the local Emergency Communications authorities asked me to bring the Twoer to the Waterbury, Connec ticut Armory during the Great Northeast Blackout of 1965. As a teen, it was quite a thrill to oper- ate my Twoer on generator power, and pass messages to hams at other support facilities in adjacent towns. The Heathkit Twoer and I have a long history together. It still occupies a proud place in my shack and reminds me that my early experi- ences with this little rig gave me my start in the communications industry where I have spent my entire career. I am sure that many of us A Heathkit Twoer advertisement from the December 1960 issue of QST. have similar stories. Harold Kramer, WJ1B, is the ARRL Chief Operating Officer. You can contact him at [email protected]. crystal frequency to 24 MHz, then tripled it personal experience that sparks would result again to 72 MHz and finally doubled it to if I accidentally touched the screwdriver to 144 MHz where it went “straight through” the metal case while tuning up! There was the final amplifier, a 6AQ5 power pentode also a power output metering circuit jack New Products that ran “approximately 5 watts,” according that, when used with an external meter, was Solderless BNC Connectors for to the manual. The 6AQ5 also served as the used to tune the final tank circuit for maxi- Times Microwave LMR-400 Cable audio power amplifier for the receiver. The mum power and to measure cathode current. Times Microwave Systems now offers two Twoer used plate modulated AM with good The metering jack was also put to work for new BNC connectors for LMR-400 coaxial quality audio. It could also run CW, more or CW keying. cable. The EZ-400-BM is a BNC male less, but the manual cautioned that there straight connector, and the EZ-400-BM-RA is would be “considerable back wave that may Good Times a BNC male right angle connector. The new result due to the fact that the previous trans- I made hundreds of contacts with my Twoer. crimp-style connectors do not require 1 mitter states are running constantly.” I tried My first antenna was a 19-inch ( ⁄4 wave- soldering of the center conductor into the CW a couple of times and the other stations length at 2 meters) coat hanger bent contact. These connectors are compatible with could hear the transmitter even when it was 90 degrees at the bottom with a banana plug the Times Microwave CST-400 cable prep not keyed! that was pushed into the SO-239. I was able tool and either the CT-400/300 or HX-4 (with to work stations easily in the city where I Y1719 dies) crimp tools. Price: EZ-400-BM The internal power supply used a power lived, although it helped that my parents (part no. 3190-2611), $21; EZ-400-BM-RA transformer, solid state rectifiers and a full lived on the top of a hill. (part no. 3190-2612), $33. For more wave voltage doubler circuit to provide information, visit your favorite dealer or 260 V at 90 mA when transmitting. My My next antenna was a 2 meter halo, essen- www.timesmicrowave.com. Twoer has a homebrew 12 V power supply tially a half wave dipole bent in a circle. I attached to the rear of the cabinet. You mounted this antenna on a pole outside the can see it protruding behind the handle in house and was able to extend my range to Figure 1. 15 miles or so. Eventually, I installed a roof tower and a Cushcraft beam with a Channel Tuning and Operating Master TV rotator. It was no big deal in Like most Twoer owners, I changed the those days to have a tower on your roof original phono plug antenna jack to an since outdoor TV antennas were very com- SO-239 because it made a more secure con- mon. With all of 5 W, I could consistently nection. To tune the final, you placed a work stations 30 miles from home. During #47 lamp dummy load in the antenna jack band openings, I managed to work five or and adjusted the tuning capacitor for maxi- six states from my Connecticut location, in- mum brightness. cluding a station in Maryland, which was my farthest 2 meter DX. Unfortunately, the tuning capacitor was in- side the case so you had to poke a screw- It was not that easy to work VHF DX since driver through a hole in the side of the case most everyone was rockbound and the pro- to get to it. In accordance with a suggestion cedure for calling CQ and tuning for a reply found in a 1965 QST “Hints and Kinks” col- was quite different. When calling CQ, you umn, I put some heat shrink tubing over the also defined your tuning range. For example, screwdriver’s metal blade since I found from “WJ1B calling CQ and tuning from 145.20 QST ® – Devoted entirely to Amateur Radio www.arrl.org June 2013 97.
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