RECEIVERS I HAVE KNOWN - Part 2 - Roland Richter
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| Hallicrafters SX-111 - Backup on ham bands and often used in 31 meters covered by the WWV band switch position Very good optimum bandwidths for AM and SSB. |
RECEIVERS I HAVE KNOWN
Part 2
Guest Contributor: Roland Richter WA5IEX / WPE5DIE
| Guest Contributor: Roland Richter WA5IEX / WPE5DIE |
There were many Facebook "likes" and comments for Part 1 of Roland's article. If you missed it, here's the link: Receivers I Have Known - Part 1. Now settle back and enjoy Part 2!
PART 2:
13.National NC-190. While at Ft Polk, my qualification for proficiency pay finally caught up with me and I got seven months back additional pay at one time. With that money burning a serious hole in my pocket, I made a weekend trip to Houston to visit friends and make a foray through two radio stores that in the seventies still carried used equipment. I was looking for a good general coverage receiver to replace the SX-99 I had let get away in Asmara. In Long's Electronics I found a real treasure: a near mint condition National NC-190. This was a dual conversion receiver that tuned from 540 kHz to 30 mHz with ferrite filters that claimed 0.5 kHz selectivity ( though probably at 6 db down and with broad skirts) and had something rather unique. It had calibrated bandspread not only for the amateur bands, but also for several of the regular shortwave broadcast bands. By turning a dial between detents, the operator could choose which bandspread one wanted to use. The receiver also had a S-meter and with a 1650 kHz first IF, relative freedom from image response. When used both at Ft Polk and at my first civilian shack in Port Arthur a year later, the receiver proved a solid performer, probably superior to the SX-99. With a little alignment touch up with a signal generator the calibration of both the main and bandspread dials were very close to right. While it did not offer the 1 kHz readout of the R-388, it was certainly close enough to provide a lot of help in identifying stations. The selectivity was very good, easily allowing separation of 5 kHz stations on both shortwave and standard broadcast bands. This allowed reception of numerous Caribbean, Central, and South American broadcast stations on “split “ frequencies. When used with a two foot diameter loop antenna wound on a cardboard box, the receiver easily pulled in medium wave stations from South America. It also worked very well on the amateur bands, though not with the selectivity of my Drake 2B. Best DX with the NC-190 would be the Ethiopian Broadcast Service received in Port Arthur along with numerous utility stations from Israel, Greece, Indonesia, Australia, East Timor, Shanghai and Macao, many on a day to day, very regular basis. The receiver did all of this in Port Arthur while within two miles of a 1 kw broadcast station and about four miles away from Coast Station WPA operating with 10 kw on several HF frequencies. The receiver ended up being given to a neighbor in Port Arthur who had developed an interest in shortwave listening back in 1980. I do miss it from time to time, but know that it went to a good home. Used mid 1973-1980.
14. Collins 75A1. This receiver was given to me by a long time local ham who also owned the Motorola MSS operation where I worked for a time in 1979. He was “cleaning out” and needed to find a new home for it and a National HRO-7 that I will tell about separately. The 75A1 was the predecessor to the truly legendary 75A4. It contained pretty good crystal filters and was a great performer on 80, 40 and 20 meters, though on higher frequencies suffered a lower sensitivity than the newer designs. I did not use it very long, but did find it an excellent cw receiver particularly among strong crowded conditions on 80 and 40 meters. Using this receiver, it became a regular thing to hear the Russian amateur stations almost at will every night. This receiver went to a young man in one of my ham radio classes being taught at the time who could not afford to buy a rig, though he had great interest in operating cw. I passed along this receiver knowing it would be several steps above what might otherwise have been his first receiver. It was paired with a Viking I transmitter for his first rig. Used 1978-1980.
15. National HRO-7. This receiver was also a pass along from Art Kay, W5APX. This receiver had two RF and two IF stages along with crystal phasing and used plug in coil drawers for band changing. It, like the other National receivers in the HRO series, used the National “BN” dial that had small windows around the periphery of a large tuning dial that changed as the dial was rotated, giving an effective twelve feet of band spread. By changing jumpers on the coil drawer, you could select whether the coil would cover a wide range of frequencies ( for example 3-10 mHz) or bandspread to spread the 40 meter band over almost the entire range of the dial. There was no direct frequency calibration for the dial, but a graph/chart on the front of the plug in assembly that would allow interpolation of frequencies amazingly closely. The receiver only came with two coil assemblies...ones for forty and twenty meters, though the eighty meter band could be covered in the general coverage mode of the forty meter coil. The receiver was amazingly stable and sensitive on the bands for which I had the coils and was excellent for AM and CW reception. In the narrowest position, CW reception was amazing, slicing signals out of heavy interference quite nicely. The BN dial gave great bandspreading action.The receiver came with the matching speaker and when set in the widest bandwidth position would give great quality sound on broadcast stations. Over a period of time, I created my own frequency conversion charts with enough reference points that allowed very good frequency determination. The receiver was particularly good in pulling out weak signals in the 60 and 90 meter tropical bands and the crowded 49 meter shortwave broadcast band. It was with this receiver than I was able to log a great number of African stations and stations from Papua New Guinea and Indonesia in the 60 and 90 meter bands for the first time. It was most often used in Port Arthur on a 200 foot flat top long wire fifty feet high that ran across two city lots. Later, during a period of time when I found myself living in apartments with rather limited antenna possibilities, the HRO-7 continued to be a great asset in pulling out signals that were weak or buried in the noise. Used 1978 though 1999.
16. Hallicrafters SX-62. This is one my all time favorite receivers, not just because it was a great DX machine, but because it is just, plain classy. I was given this receiver not working. It was another deal from an older ham radio friend who was cleaning out and downsizing. The radio was deaf to RF. It made noise that indicated at least the IF's and audio were working, but it was not picking anything up. Troubleshooting indicated the 7F8 mixer/converter tube was not working. This is a very rare tube and I was having trouble finding it. I carted the receiver around through a move out to Kerrville in West Texas ( not an easy thing, since the radio is BIG and weighs about fifty pounds!) but I did not want to turn it loose. Its a classic Hallicrafters design with a huge slide rule dial. It covers 540 kHz to 108 mHz with both AM and FM detectors. The huge dial has markings on it for individual stations...a good bit of it covered with dots with country names next them. It has two RF and two IF stages and a crystal filter but the phasing control is not on the front panel, but beneath the chassis and must be just preset during alignment. I was lucky enough that one of the students in the ham class I taught out at Kerrville had 2 (!) 7F8's in his junk box and both worked! The radio came alive. After a careful alignment, it worked great with the exception of the upper VHF band...never figured out what was going on with it. It took a little spraying of contact cleaner on the band switch and on the wiper contacts on the variable capacitors to get rid of the “crackles” but the radio worked very well. On a good external speaker, the audio is superb. With selectable bandwidths, the audio is great for casual listening or it can tighten down for digging out weak stuff or stations on a crowded band. For an older receiver it is reasonably stable for copying cw and SSB though it does not have a product detector. This quickly became my “living room” radio for listening to BBC news broadcasts, music from Croatia when during their wars the HF stations relayed the local FM networks and the Voice of Greece, again for great music. There is no bandspread, but the long dial and geared down tuning make it tuneable without it. It is also a great performer for medium wave DX. This was the radio I used to look at in the Wards catalog and drool over as a kid back when Wards and Sears still sold such things in the fifties! One really neat thing about the receiver is that when the bandswitch is turned, dial lights switch to light up the specific row that is selected on the huge slide rule dial. Used 1980 though 1999.
17. BC-342 ( military surplus) I came upon this radio in a trade with another ham who needed a high voltage transformer I had. I had just moved to Kerrville and did not have the SX-62 fixed yet and did not have another general coverage receiver with me. The BC-342 I have tunes from 1500 kHz to 18 mHz. It has two RF stages and two IF stages and a crystal filter with front panel phasing control. It also has an interesting noise fighting feature. There is a second “ Noise Antenna” input which I believe is fed into the input coupling circuit in such a way as to be out of phase with the main input. You put an antenna connection there that has a wire in the noise source area but not necessarily out where it can receive the signals you really want. It is somewhat effective. This idea has been put into these noise cancelling devices that are being sold these days for a lot of money, probably with the concept developed to a higher level. This idea was apparently conceived back in the 1930's! There were several versions of the BC-342 and BC-348 which were similar except for frequency ranges and whether an internal AC power supply was included. The receiver does not have bandspread, but the tuning rate is quite slow and the calibration is good. The tuning across each band is pretty linear also. The oscillator is enclosed in a shielded box, including the section of the variable capacitor that tunes that stage. The idea behind this was to reduce the radiation of the local oscillator to avoid detection by the enemy! The other unusual aspect of the design is that the volume control controls the gain of both the audio stage and the RF stages. The AGC is defeatable, which helps in copying cw with this receiver. It is actually quite good for short wave listening, other than the frequency readout. But for those of us who entered the hobby well before the digital age, this is not a problem because there are all kinds of peripheral ways to telling where in the band you are if you know your way around! I have also used this receiver as a backup, for amateur use on the 160 meter and 30 meter bands and as a WWV monitor. The selectivity is more than adequate for dealing with the crowded 49 meter band and sensitivity is excellent up through 18 mHz. Stability is good after a half hour warmup. It will stay properly tuned onto WWV at 10 mHz for days and days without touchup. With an external speaker, the audio quality is pleasant. And while the controls have gotten a little scratchy in recent years, it still works amazingly well for an almost 75 year old radio! Strong signals will never overload it!! Used 1980 to date. Still in use.
18. Collins 75S-3. I obtained this receiver from a fellow ham in Kerrville in 1980. It was an amateur bands only receiver, but by putting crystals in the various amateur band slots in place of the originals, it could be made to tune virtually any 200 kHz wide frequency range between about 3 and 30 mHz. It had a tuneable preselector and a 200 Hz cw filter with very steep skirts. The filters in the radio were not really appropriate for AM reception, though it was possible to do so by disabling the Beat Frequency Oscillator. AM was best received in the SSB mode. This receiver was the absolute state of the art when it was built and to this day is excellent for CW and SSB. It is very quiet, almost frequency monitor stable and extremely selective. I found very few birdies even when using odd crystals at the edges of the ranges, usually only in the segments near its tuneable IF. I used this receiver mostly in the amateur bands where it was a star performer in digging out weak cw signals in very crowded pileups on DX stations or in contests. It was also the absolute best in tuning utility stations on SSB and CW. Even when used in an apartment with indoor antennas or short window antennas, it would pull in great DX. There was absolutely no overload or spurious responses and frequency readout on the analog dial was easily accomplished down to 1 kHz. The only negative was the limited tuning range and availability of crystals for all of the ranges I wanted to tune. It was possible to set this receiver up on aviation route frequencies or Coast Guard frequencies on SSB and leave it there for weeks at a time with no noticeable drift. This was the best receiver I ever had for such listening, after all, this is what it was designed to do: tune and hold SSB signals in the best possible way! On the ham bands, I often used this receiver paired with an HT-37 transmitter or Icom 701 and Icom 720 transceivers. It would totally outperform the receivers in any of the Icoms or in a Kenwood TS-130 or Yaesu FT-757 transceivers I was to use while I had it. It was the only receiver I have had that would give the Drake 2B a run for its money. Used 1981-2007.
19. Icom 701. I hesitated at first to list this among my receivers, because in actuality, it is an amateur band transceiver. But, since some my DX listening does involve logging amateur stations, and such loggings often accompany making ham contacts, I guess it fits. It did put many stations in my “heard” logs that did not make it into my “ worked” logs anyway. It also allowed tuning the 41 meter shortwave broadcast band and part of the 19 meter band above the 15 mHz WWV. In fact, it did a pretty good job of pulling out some serious broadcast DX on those bands. It also pulled a few stations out that resided in the 75/80 meter band. It was a first generation fully solid state radio and as such, did have some overload issues. It did not have really narrow cw filters, but did OK. It was certainly sensitive. When operating mobile during my traveling engineer days it would do a great job with small antennas. I did not always work all that I heard, but there were many JA's and VK's heard on 40 meters with the Hustler whip on the back of my Chevy S-10 pickup. There was even one morning early when it pulled in an Indonesian ( YB) station on 40 on the mobile whip. Pulling out Russians on 20 meter SSB on the mobile antenna was also a common event. On 80 and 160 meters, the front end shortcomings became more noticeable, with noise and intermod showing up. While using it as a ham rig, I would often use a second, separate receiver with it. It held up amazingly well. I believe it was built in the early seventies. I know a fellow ham had one in Port Arthur in 1975. I used it as a working rig until it started failing in 2012. That's at least 37 years that particular radio worked well. About ten years much of that time was running mobile in a pickup truck. I think I got my money's worth out of it. Best DX on it would include Pitcairn Island on several bands, Hong Kong, China, Willis Island, Chatham Island, Christmas Island, and hearing Israel on 80 meters. Oh and lest I forget, several Hawaiians and the Galapagos on 160 meters. Used 1981-2012.
20. Icom 720. After putting the '701 on this list, I simply could not leave off the Icom 720 that joined its older brother in the mid 90's. It not only had the WARC amateur bands on it, but also included a general coverage receiver. I picked it up for only $250 at a hamfest and think I got a great deal for the use I got out of it. With the 500 Hz cw filter it had, it did really well on the amateur bands, though it had the same shortcomings on 160 meters as did the '701. It was plenty sensitive and I heard plenty of DX even on that band ( including some Europeans and Japanese on 160 meter cw) but it was susceptible to noise and overload, and I often found myself using another receiver ( usually the BC-342 or a Hammurland HQ-170, but I get ahead of myself). It was pretty good for utility DX, and while not as good as the 75S-3, was much more convenient to use because there was no need to open the case and change crystals to change bands. When used with some tall verticals and an 80 meter Windom a bit over 40 feet high it did a great job on the higher utility bands, snagging some great CW signals in the 18 and 22 mHz bands. It was also handy for utility SSB work with really good filters. Some of the better things logged included Coast Guard stations in Alaska working vessels up there in the 6 and 4 mHz bands. There were many evenings when I was working on repairing a piece of gear or working on a building project that I would just leave it on, tuned to one of the USCG frequencies and listen to the search and rescue work. While the receiver did cover all frequencies from 500 kHz to 30 mHz, it was not so good for broadcast stations. Even listening in the SSB mode zero beat with the AM carriers, the audio quality was not so good and the bandwidth a little too narrow. That was a bit of a disappointment because that was one of the reasons I wanted the rig in the first place. I had wanted a good general coverage receiver with direct frequency readout ever since using the R-390's and the R-388 in Asmara. The '720 would pull out weak stations and they could be identified, but it was not really pleasant listening. The audio quality even on an external speaker or headphones was not nearly as good as the older '701. I am not sure what year the '720 was made, but it did not survive much past the demise of the '701. It also faded away in a cloud of instability, low transmitter output, and general noisy controls and bandswitch malaise in 2012. It was probably at least 30 years old, maybe more. The thing about the “newer” generation of gear is that it is just not as repairable as the older tube boat anchors. There reaches a time when its just time to let them go. I did pull the IF filters out to save for possible future projects. Used 1996-2013
21. Radio Shack/Sangean DX-440. This receiver appears a bit out of order simply because for some reason I wanted to put the Icoms together. I bought this little radio new during a period of time when I was living in apartments and could not have big antennas or transmit at all except mobile. I actually bought it on impulse. I had been using the SX-62, my BC-342 and Icom 701 to listen in my apartment in San Marcos with indoor wire antennas and one short wire dropping from a second story window down to a fence enclosing my ( ha!) back yard : a ten foot by ten foot area of concrete pad and grass. I saw it in the store when I went to buy more wire to try to extend my antenna. At first I was not impressed, but I tuned around a bit and even with the whip pulled in WWV on several frequencies inside the noisy store. I noticed it had a “bandwidth” switch marked “wide” and “narrow” and remember thinking, “ this can't be much”. But when I tried it on the local broadcast station where I worked that was only a mile from the store ( I was really giving the radio a break!) I noticed that in the “narrow” position it cut quite a bit of the high frequencies off the audio. Hmmm. That would mean at least 5kHz selectivity since I knew our station had pretty good high frequency capability. On a whim, I bought the little radio on the spot, digging deep into my social life money ( most of it was spent at a place called The Green Parrott on the square in San Marcos on nachos and cold beers anyway so spending it on the radio was probably an improvement).
I was not to be disappointed in my investment. The little radio proved a great performer, not just for the money but overall. It was very sensitive and did well on the short apartment antennas and did not overload when I did get a decent longer and higher wire up. The performance on the long wave band was much better than the Transoceanic had been. In fact, it lit the fire under my desire to start logging non directional beacons. Even with the internal loop it did well, with at least one station logged on every possible NDB frequency within six months. The directionality of the internal loop allowed as many as three to be picked out on some frequencies. It also did pretty well on the broadcast band. On the shortwave bands, it did have some spurious response issues on the wire antennas, but the use of an MFJ antenna tuner used at times for tuning the mobile antenna for ham use seemed to take care of that. I am not sure if it was the increased selectivity or the impedance matching or just the isolation of any detuning effects of the external antenna, but it took care of almost all the problems on the HF bands. Later when my dad and I built a large tuned loop antenna for use on the broadcast band and low frequencies, the radio really came alive. The three foot diameter loop had a really high Q and had very deep nulls, but the sensitivity of the DX-440 was good enough even with the smaller aperture of the loop compared to the longer wires did well in pulling in good DX, especially after a little MFJ tuneable preamp was added to the mix. Best NDB DX on the '440 on long wave included ZBB from Bimini in the Bahamas, several Cubans, Venezuela and a few Canadians. The best overall DX was Algeria on long wave broadcast using the 50 foot high windom and a home made tuned antenna coupler later in Waco. Oddly, I was never able to hear the French or Luxembourg high power long wave stations. The little radio also did very well logging cw signals in the maritime bands. All of the “regulars” were easy, and there were many loggings of Shanghai, Macao, Indonesia, Israel and others. Among the broadcast stations, the best DX included VL8A, VL8T, and VL8K from Australia in the 120 meter band, logged on several occasions, along with a huge list of Chinese, Indonesian and Papua New Guinea tropical band stations. It survived twenty years of daily hard use not only as a DX machine but as an alarm clock and met its end when the “ lock” switch on the front got broken in a fall from a night stand. Of course it failed in the “locked” position and since the radio was off, it cannot be turned on. I've kept it in hopes that perhaps I will run into someone with younger, steadier hands that might be able to fix it. Used 1988-2009.
22. Potomac FIM-21. This is another non-receiver used as a receiver. The FIM-21 is actually a piece of test equipment. It is a portable, calibrated Field Intensity Meter used to measure signal strength for setting up and maintaining AM directional broadcast stations. It is very sensitive, selective and has a highly directional loop antenna. This made it a very desirable AM DX receiver as well. It was designed to detect and measure signals down to a fraction of a millivolt in strength, and with its extremely directional loop having particularly deep nulls, its great for eliminating even local strength signals to allow distant signals from another direction to be heard. Its other attribute is being able to do this within very high RF fields. This device actually belonged to the radio stations I maintained and built and was used primarily for DX-ing while on transmitter watch inside a transmitter building. There were many times I found myself on such duty with the job of watching meters to make sure the transmitter and directional system was operating withing tolerance and logging meter readings. There were times in Laredo, Texas where the FIM-21 allowed me to log some really good DX while in the same room with an operating 10 kw transmitter! Used 1988-1991.
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| FT-757-GX - Daily use on ham bands and occasionally SWBC |
24. Hallicrafters SX-96. This is a dual conversion receiver that tunes from 540 khZ through 30 mHz. I have had this receiver almost twenty years and actually have used it very little. I obtained it in a trade for some equipment an elderly other ham wanted for parts and used it mostly in an apartment as a casual listening receiver. It is really quite good. Its very similar to the SX-100 in that it is dual conversion and has selectable sideband reception along with a crystal filter. I have used it for general listening on indoor antennas and found it very selective and more stable than the SX-99 I had owned years before. I had planned to take it out of semi retirement and use it for more serious DX-ing when I obtained an Icom R-75 and it still sits on the shelf. It is very stable on SSB and CW signals and has excellent audio quality when used on an external speaker. It also has the classic Hallicrafters look to it that is pleasant with a large S-meter between the two half moon dials. Used 1992 to date. Still in use.
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| Hallicrafters SX-96 - In use almost daily... More for listening to programs. Very nice audio quality. Great for BCB DX |
25. Mackay 3001. This is a shipboard receiver that is actually a highly developed regenerative design with an RF stage that tunes from about 15 kHz to 600 kHz It was designed and used aboard ship for long wave reception. I found it at a hamfest in Dallas in the outdoor flea market. Someone had fully restored it and it was in excellent condition, but the person selling it was probably not the person who did the work because he let it go for $40.00!! I am guessing he probably got it as part of an estate sale deal and since it was not for use on the amateur bands did not see its real value. This radio even had on it the identification plate for the ship that it served on with the ships call letters ( KCNX ) still on it! It was also obvious what its actual duty had been aboard ship because the dial face had a “shadow “ burned into it all across the dial except in one spot: right across 500 kHz. You can actually see the shape of the dial pointer across that frequency. In those days, shipboard operators were required to maintain a watch on 500 kHz which was the international distress frequency. There was to be a silent period once an hour to allow weak signals to be heard there. The little radio has a history! It also is a great performer on these bands. It appears to have double tuned RF stages and the renerative detector. At least it has a four gang variable capacitor. I have used this receiver for a great deal of DX-ing of non-directional beacons and it has been excellent for that. Also in the days before the end of the use of cw by ships, it was used to log much cw activity in the long wave band between 400 and 500 kHz. It was probably the final state of the art design for regenerative receivers and is useful today for such things. It has also allowed reception of some pretty good DX on the small slice of the standard broadcast band that it covers! Used 1994 to date. Still in use.
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| My NDB DX machine once installed on a Great Lakes ore carrying vessel. Tunes from 15-600 kHz. Regen with rf stage. No artifacts from broadcast stations because there is no conversion!! Very selective. Still has call letter card from the ship on its panel( KCNX) |
This article first appeared in Roland's DX Adventures post of November 17, 2013.
Don't forget to check out Roland's wonderful radio blog called "DX Adventures - The life and times of a world traveler who seldom actually leaves home!" There's a wealth of experience and knowledge at his website for your enjoyment. http://dxadventures.blogspot.com
73 and good DX to you all.
Rob VK3BVW
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