HFU HF Underground
General Category => General Radio Discussion => Topic started by: alpard on August 03, 2020, 1211 UTC
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Can vintage analogue / tube radios be used for SWL BCL Dxing?
Do you use one? What are they? How do they perform?
Any advantages or disadvantage for BCL/SWL DXing using one of those vintage analogue radios?
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Absolutely. My first "serious" general coverage receiver was a Hammarlund HQ-180. I think it would still hold its own today for SWL.
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I have a half dozen tube receivers that I use for swl dating 1950 or earlier. Getting to know the radio is key, especially what it receives well and how the frequency aligns up to the dial. I save my swl on the tubes for generally well received music (including am pirates). One trick I'll do is tune in to my desired broadcast on PL 880 then match reception on the tube. Music programs on the '37 Zenith Console make my home sound like a concert hall, live sports on shortwave tube radios are also a joy. There are many, many music programs I have enjoyed on these sets. I have found analog sets to drift off the frequency from time to time and may not receive as well as the Tecsun, but for a strong signal music program the sound coming from a wood cabinet tube radio can't be beat.
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I use a National NC-125 and -183D. They all work well. During the summer, the NC-125 is on the porch connected to a pair of Bonito Boni-Whip antennas with a Quantum Phaser. Aside from thunderstorms, it works pretty well. In the winter when I'm inside, I use a NC-183D that's connected to a Wellbrook ALA-1530S+ and that one also works very well.
They both compare favorably to a Sony ICF-2010, but the 2010 has a bit of an edge with somewhat better reception, but the main improvement is the sync detection.
The tube radios sound better. Identifying the frequency is a bit harder due to the analog dials that are rarely correct. On MW, its not as big of a deal, but on SW that's a different ball of wax and I usually get a modern digital radio to verify the freq.
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Huh... For about a year, I also had a Hammarlund HQ-180. Very, very drifty for the 1st 30min, but was decent to use after that. (Ended up selling that to a friend whom really wanted more than I did.) Tell ya what though, If I was offered a Collins 390A, even if it needed work, I'd be hard pressed to turn one down. Unfortunately, the last tube rig bought was a Zenith Trans Oceanic that came all smashed up from the carrier. Got our money back, but still a pity to see that rig in about 20-some pieces. But anyway, a tube receiver is a different flavor to use, tune, and have fun with. Not to mention the audio quality from many of them. Very warm & pleasant.
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RA17?
Still incredibly good, however it's not American so may be rare in US.
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Interesting to know that there are still many tube / vintage analogue receivers getting used for BCL SWL DXing.
I have a few old receivers that I am planning to set up for DXing, but wan't sure if they would be up for the job.
I guess the main problem could be finding out what the exact freq, it is tuned to, when heard stations for the first time in languages that I don't understand.
And to go to the exact freq. to tune up for a station that I want to listen to.
I suppose a digital readout receiver could be used side by side to confirm the freq. but then it is not 100% analogue receiver at work is it? :))
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I guess the main problem could be finding out what the exact freq, it is tuned to, when heard stations for the first time in languages that I don't understand.
And to go to the exact freq. to tune up for a station that I want to listen to.
I suppose a digital readout receiver could be used side by side to confirm the freq. but then it is not 100% analogue receiver at work is it? :))
Depends on how pure you want to be. You could calibrate your analog scale, but still hard to tell if you're on 15420 or 15425.
When I DX, I hear something on the radio and verify it on a receiver with a digital display if the freq is in question. And if I don't recognize the station, then I look up the SWBC sked online or with DX ToolBox, and may even search the Internet for the distant station online to listen to their live audio stream, if available.
You can also get a notion of roughly where you are if there are some known stations around the station of interest. If you hear WRMI on 9395 below the station of interest and Voice of Greece on 9420 is above it, then that narrows it down to 9400, 9405, 9410, 9415, assuming that station is on the regular 5 kHz channels. If they're on 9407.5... you're not going to see that on the analog display (unless highly calibrated and measuring with a micrometer). And you can use the other known stations on the band as frequency markers.
I've read of some mods where a digital frequency meter can be added to some of these radios to one of the stages. But then that is little different than using another radio with a digital display.
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Great advice and info. Thanks.
I was trying to synchronise the freq. my XHDATA D-808 and TRIO 9R59D on the station which was on 6135 kHx on the D-808.
But after tuning for the signal on the 9R59D, it was reading around 6300 kHz when the freq. were synchronised. It was very tricky. I had to also tune the Band Spread dial to make the 9R59D to read about 6100 - 61500 kHz. It was still rough reading.
It would be great to be able to add digital freq. readout displays into these analogue tube radios. I am not sure how practical it is to add them. The only device I know is the freq readout module for AD9250, which wired into my TenTec VFO, and worked. But for the older tube rigs I am not sure if it is possible to wire the module which has plugin freq display board.
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If by "analogue" you mean non-digital tuner readout, sure -- a lot of radios are still good, just as long as they are operating correctly. My Yaesu FRG-7 is still very good on SW and excellent on MW. You get within 5-10 khz using the analog dial readout, which is close enough for SWBC and even most ham listening. On MW it's easier because the MW band is fairly standard -- stations are either 9 or 10 khz apart and if you know the band in your area it's easier to figure out where you are.
Other analog radios of the pre-digital era can have good performance, and the readout still will leave a certain amount of guesswork, depending on the way the radio's tuning scheme is set up -- some of the Panasonic and Sony radios had crystal markers, which would help in tuning.
But the radio circuits themselves were probably as good as most DSP chips in SW portables today. With SW, a lot of it is the antenna, anyway.
Just my 2 cents.
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Another thing is that, if you want to monitor a station on the freq. let say 4055 kHz Radio Verdad from Guatemala.
Then how would you be able to ensure your analogue tube radio is tuned for that freq. spot on?
This R. Verdad station sometimes bursts into good signal reception at nights, but during most days and times, it is just hash noise on the freq. hence I set my radio (TECSUN PL-680 or XHD D-808) for stand by on the freq. With analogue tube radio like my 9R59D? not sure if it is possible.
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Some receivers have a log scale, which is a linear scale (unlike the frequency scales). Can use that to get close and that's usually close enough for AM. But its not exact, as there may be some unaccounted for drift.
Then make note of where 4055 is on the log scale and tuning there in the future should be reasonably fine.
Some radios have a bandspread knob as well as the main tuning. Usually that's to do finer tuning in a band. That dial will have to be set to a certain point, so the main tuning knob will indicate consistently.
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Can vintage analogue / tube radios be used for SWL BCL Dxing?
Do you use one? What are they? How do they perform?
Any advantages or disadvantage for BCL/SWL DXing using one of those vintage analogue radios?
As you have seen from the responses so far, yes, absolutely, you can use a vintage or tube receiver (often called "boat anchors") for SWL BCL, or any other kind of listening, if that is what you want. And some of them can perform extremely well. If there is a major weakness it is that some older radios, especially if they were lower end sets back in the day, can be a little less sensitive above about 15 MHz.
Advantages, cool factor, sometimes sound quality, and really that is about it. There is nothing an old radio can do that a quality modern radio cannot do.
Disadvantages, many. They can be a bit less stable in frequency, they can take a long time to warm up, they can be hard to find parts for, they use way more power and can warm up a room (both a plus and a minus, depending on time of year), they often have less adjustable or more limited filtering, etc.
If it sounds like I am running down the vintage stuff...far from it, I love it. But there are things to consider if you are going to use older stuff.
Here I use a variety of older gear. The core radios in the shack are modern, various SDRs and traditional modern receivers, but I also keep a couple older radios in play all the time, and I rotate the old radios used in the shack. Today I have a Hallicrafters SX-28, Hallicrafters SX-62A, and Hallicrafters SX-71 in the shack, and an LM-18 right next to them (more on that later), a couple of months ago it was a National NC-173, Hammarlund SP600, and Hallicrafters SX-42.
I guess the main problem could be finding out what the exact freq, it is tuned to, when heard stations for the first time in languages that I don't understand.
And to go to the exact freq. to tune up for a station that I want to listen to.
I suppose a digital readout receiver could be used side by side to confirm the freq. but then it is not 100% analogue receiver at work is it? :))
Another thing is that, if you want to monitor a station on the freq. let say 4055 kHz Radio Verdad from Guatemala.
Then how would you be able to ensure your analogue tube radio is tuned for that freq. spot on?
You could use a digital frequency meter on the LO or VFO of the old radio. There are many kits to do so. You are still using only the vintage radio, but you have added a digital readout to the vintage electronics. Pretty easy and it can be non-invasive, if you are careful in the implementation you can return the radio to original configuration with no sign it ever had the readout associated.
Or you can do it how we did it back in the day. Use an external, period correct, frequency meter or frequency standard.
An external fixed frequency standard can be turned on that will generate multiple signals / markers on known frequencies. They generate multiple harmonics of a given frequency, for example in the 1 MHz setting they generate a tone / marker / signal every 1 MHz (1000 kHz), so they are at 1, 2, 3, 4, 5....et MHz. In the 100 kHz setting they generate a signal every 100 kHz, so it would include things like 3500, 3600, 3700, 3800, 3900...8100...15400, kHz, etc. And in the 10 kHz setting they generate markers every 10 kHz, 3500, 3510, 3520, 3530, 3540 kHz, etc.
In your Radio Verdad example on 4055 kHz: you click the switch on the freq standard to the 1 MHz position. Even very coarsely defined frequency scales can normally allow you to get within one MHz. You tune the radio to 4000 kHz by finding the tone / signal of the freq standard. You then click switch to the 10 kHz position, tuning the radio up until you have counted 5 tones, you are now at 4050 kHz. Tune to the next tone up, now at 4060 kHz. Go back to half way between (by sound or by dial indicator) the 4050 and 4060 kHz tones and you at 4055 kHz.
It sounds bulky, but is really very easy.
My favorite way would be an external harmonic frequency meter, like the military surplus BC-221 series, or the LM-XX (multiple numbers in the XX) series like an LM-12 or LM-18. These systems can tell you the frequency of any signal you want or preset the frequency of the radio with an analog radio to under 0.1 kHz resolution.
Quite a while ago I put together a basic web page talking about these frequency meters, and how to use them:
http://www.tokenradio.net/token/BC221.htm
From that page you will also see a link to some boatanchor dials, and why such a meter can be helpful.
T!
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I picked up a Yaesu FRG-7700 for $160 years ago and wouldn't part with it for 3x that amount, Wonderful circa 1978-1982 SWL receiver.
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Great info & advice. Thank you.
I will try my TRIO 9R59D for some AM DXing. :)
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I picked up a Yaesu FRG-7700 for $160 years ago and wouldn't part with it for 3x that amount, Wonderful circa 1978-1982 SWL receiver.
What do you find the 7700 good and special compared to the other HF radios? Thanks.
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Sensitivity, calibration and separation are all spot on. Using the same antenna (the Alpha Delta Sloper) thru a splitter, the FRG frequently picks up SWL AM signals some of my other receivers do not. Audio quality is very good (a front facing speaker is always better). My only complaint(and it is minor) is that it drifts slightly on SSB. I got mine on EBAY for only $160 because , I suppose, it didn't have the optional memory card. I checked EBAY this morning and there are only 2 today, both rather high-priced. But keep checking - they surface on EBAY on and off all the time.
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One of the eham reviews on the 7700 was negative on the radio. So I stayed away from it for a while.
"Not much chop Time Owned: 3 to 6 months.
Had one
At same time had FRG7 and kenwood r1000. Kept them two, sold the 7700.
Filters too broad, not that sensitive, overloaded with images on a big antenna.
Nothing to write home about. Is Ok if you see it at a cheap price and dont expect much. But there's better buys for your buck."
But maybe his one was a lemon?
I recall times when I was using Yaesu radios. Mine were a FRG-7 and FRG-7000. At the time I thought they were great. The 7000 pulled a lot of DX at the time especially, but both of them sounded rather wide and loose at times. I did let them go, and got a few portables. Now I got a used TECSUN S-2000. It is not a perfect radio, but seems doing better than all the portables I own and use.
Still have the Yaesu FT-101ZD. I love this radio for its fantastic SSB and CW receiver audio on the ham bands. Haven't operated it a few month now due to the ham bands still not good condition.
But FRG 7700 and FRG 8800, I recall that they used to be going for high prices in used market in 1990s. I used to drool over them, but always thought too much money for what they are.
Recently also I got feeling that most of these old rigs must be developing some sort of reliability problems with the parts going bad due to age. But with very positive remarks and recommendations on them by the real users and experienced DXers like yourself, will make us to look at, and reconsider them again.
Another important questions is, could they be repaired / restored to good daily working condition again, if they stopped working one day. Parts availability, repairability by DIY or even by the professionals .. etc issues like these creep into the questions.
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The FRG-7700 is not a bad radio. It is not particularly good (when compared to really good radios, like the NRD 525, Drake R8, or something), but not bad. It competes well with other receivers in the same price class and age, it was a mid cost entry / mid level desktop in the day. I have owned several over the years, and still own the original one I bought new in 1980.
The review on eham that states low sensitivity, wide filters, and overloading is valid, but the question becomes, what was he used to? I find it hard to believe the two he lists, the FRG-7 and the R-1000, were any better.
The FRG-7700 sensitivity, by spec, is about 0.5 uV in SSB mode in the HF range. The Sherwood Engineering tests showed their example at about 0.2 uV, my current copy runs about 0.24 uV for 10 dB S/N in 2.7 kHz. This is not bad, but certainly not top shelf. Fortunately raw sensitivity is not often an issue on HF, where you tend to be noise limited, not sensitivity limited.
The FRG-7700 does have limited filters, 3 filter widths in AM (12 kHz, 6 kHz, and 2.7 kHz), one width in SSB and CW (2.7 kHz) and one width in FM (15 kHz). This amounts to a fair selection of usable bandwidths in AM, an adequate "normal" filter in SSB, and a far too wide filter in CW. And while you can always change the filters out for different ones, there are not multiple selections for each mode, so you still only end up with 3 in AM, one in FM, and one for both SSB and CW. And if you put in a nice tight CW filter then it makes SSB almost unusable. From the filter aspect the radio was pretty obviously aimed at the SWL primarily listening in AM, that wanted SSB, CW, and FM capabilities also.
As for overloading, yes, I have seen FRG-7700s do that, but typically in pretty extreme situations. While they can overload I have not seen it as a big problem with them. And if / when it does overload you can crank down the gain. There is a front panel variable attenuator, and there is also a back panel local/DX switch.
The FRG-7700 is an in between tech radio, a world that really only existed for a few years. It is an all solid state radio with a digital display, but it is not a digital radio. Yes, it has a digital display, but the radio itself and all the frequency sources inside it are analog (unless you have the add on external memory module), using crystals, PLLs, and similar sources. The digital display is a digital frequency counter that is used to measure and display the analog VFO frequency.
The FRG-7700 is a decent desktop that works well, if not a stellar performer. If you compare it to top end radios it will come up short, but if you compare it to lower end desktops, like the Radio Shack DX-302, it is quite good.
T!
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Great detailed info about FRG7700, thank you Token.
Yes, I feel it is a good useable HF receiver for DX SWL / BCL from your info there.
How would it compare with the more domestic looking yet popular receivers such as Panasonic RF-2200 and RF-3100? Because I know a very serious BCL DXer who sold his other good radios to buy the RF-2200. I was wondering if it was a good idea to sell more modern radios, and buying the ancient vintage like RF-2200? But I thought there might be something that I don't know about the RF-2200 that he knows.
Talking about the receiver over loading, is it not the case that all receivers overload at nights when the medium bands strong stations come into the right skip? They are heard all over between 2 - 5 Mhz at certain time of the nights due to them getting really strong with the night time MW skip changes in the bands? Many radios will suffer from this regardless the size of the antennas, unless they are using the built in whips.
And if fed with a cheap active antennas, then it could happened any time of the day from my experience. But are there receivers more robust in this problems?
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How would it compare with the more domestic looking yet popular receivers such as Panasonic RF-2200 and RF-3100? Because I know a very serious BCL DXer who sold his other good radios to buy the RF-2200. I was wondering if it was a good idea to sell more modern radios, and buying the ancient vintage like RF-2200? But I thought there might be something that I don't know about the RF-2200 that he knows.
On MW BCB the FRG-7700 is not as good as on HF. And the RF-2200 (I still have my RF-2200 that I bought new in 1983 or so) is very good on MW BCB. So it is quite possible the RF-2200 will beat the FRG-7700 for MW BCB, but I really think it would come down to antennas. If I can have a nice mag loop or a full sized antenna I would prefer the 7700 to the 2200 on MW BCB, but if I am antenna limited the RF-2200 might be the better option.
On HF the 7700, with a decent antenna, should be better.
I’ve never used the RF-3100, so I can’t speak to it.
Talking about the receiver over loading, is it not the case that all receivers overload at nights when the medium bands strong stations come into the right skip? They are heard all over between 2 - 5 Mhz at certain time of the nights due to them getting really strong with the night time MW skip changes in the bands? Many radios will suffer from this regardless the size of the antennas, unless they are using the built in whips.
And if fed with a cheap active antennas, then it could happened any time of the day from my experience. But are there receivers more robust in this problems?
While it is technically possible for any receiver to overload, it should not be the case that all receivers overload at night on the lower HF bands. None of the receivers I regularly use have much of a problem with this, although some of the lower end vintage receivers I break out will, especially if they are single conversion receivers. A receiver with good dynamic range and image rejection should be able to handle anything thrown at it by any passive antenna one might find. Overloading and images should be the exception, not the rule.
Portable receivers often have issues with overload and images, but decent desktops are much less prone to this problem.
By their nature portables tend to be less robust when it comes to front end design. They are built to primarily work with their built in, small, inefficient, whip antennas. A portable on a good sized external antenna may indeed overload or show image often. And such a radio on an active antenna is asking for it to happen.
T!
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I have a long wire in the garden about 60 m long, and when it connected to the radios, and tune about on the tropical bands 3 - 5 Mhz, there are always a lots of MW stations breaking in all over the place. When I switch back to MLA30, the break through is less maybe 2 or 3. It is OK when the wire is connected to straight to the radio, but when ATU is in between, and when the signals are peaked with the ATU, the MW signals becomes very strong too.
It is also worse between 8 - 11pm at nights. After that time, it gets a little better. I am not near any of the strong MW transmitters either.
I have a vintage single conversion receiver Lafayette HA-600, and yes it overloads even during the day. So have to make sure it is not fed with the large antennas.
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What do you have for a good Independent Earth Ground? A decent Ground cable / rod, connected to your receiver's chassis, can improve MW rejection to, even a single conversion, receiver, when DX'ing the SW bands. Especially a double and triple conversion receiver. Then, to improve Ground soil conductivity, water the area where the Ground rod is pounded into. And BTW, a good Earth Ground can also improve your receiver's sensitivity from LF to about 15Mhz.
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What do you have for a good Independent Earth Ground? A decent Ground cable / rod, connected to your receiver's chassis, can improve MW rejection to, even a single conversion, receiver, when DX'ing the SW bands. Especially a double and triple conversion receiver. Then, to improve Ground soil conductivity, water the area where the Ground rod is pounded into. And BTW, a good Earth Ground can also improve your receiver's sensitivity from LF to about 15Mhz.
I don't use any Earth Ground. It is because my radio shack is on the upstairs of the house. I tried using the wire connection to the water tank in the house and the water pipes for the ground of the radios. It was a disaster , because apparently the water pipes are used for the mains electricity Earth ground here. When I connected that wire from the water pipes to my radios' ground connector, it was total wipe out of the HF freq. on some of the bands including the tropical band. The MW signals was heard everywhere, so disconnected it immediately. Since then I had not connected anywise to the Ground post of any of my radios.
Maybe it has to be a metal rod driven into the soggy ground?, and run a thick wire to the radio shack? I wasn't sure, if it would be making such an improvement on the HF reception.
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Great detailed info about FRG7700, thank you Token.
Yes, I feel it is a good useable HF receiver for DX SWL / BCL from your info there.
How would it compare with the more domestic looking yet popular receivers such as Panasonic RF-2200 and RF-3100? Because I know a very serious BCL DXer who sold his other good radios to buy the RF-2200. I was wondering if it was a good idea to sell more modern radios, and buying the ancient vintage like RF-2200? But I thought there might be something that I don't know about the RF-2200 that he knows.
The problem with getting a Panasonic RF-2200 is they are old radios, with horrible bandswitch mechanisms that did not age well. You could get a new Tecsun that had similar MW performance and had no such issues -- besides, a Tecsun would be cheaper. I know a lot of DXers rave about RF-2200's but I think their rep is overblown. They're great -- that is, when they are working. I have a Sony IC5900W that has similar switch mechanisms and they were impossible to fix. A lot of guys who get RF2200's find they have to either dig into them and try to repair them, or send them off to have them repaired. There are other older radios that are just as good, with more dependable switches. A GE SR2, for example.
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I have a long wire in the garden about 60 m long, and when it connected to the radios, and tune about on the tropical bands 3 - 5 Mhz, there are always a lots of MW stations breaking in all over the place. When I switch back to MLA30, the break through is less maybe 2 or 3. It is OK when the wire is connected to straight to the radio, but when ATU is in between, and when the signals are peaked with the ATU, the MW signals becomes very strong too.
It is also worse between 8 - 11pm at nights. After that time, it gets a little better. I am not near any of the strong MW transmitters either.
I have a vintage single conversion receiver Lafayette HA-600, and yes it overloads even during the day. So have to make sure it is not fed with the large antennas.
A simple antenna tuner will help reduce MW local interference and overload. I have a Realistic DX-160 that also is single conversion, and a simple antenna tuner helped reduce the overload. In my case (I live in a low signals area) it actually eliminated it.
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Another idea for a make-shift GND? Do you have a bed with a pretty solid steel bed frame? It will act as a counter poise, but how much so is anyone's guess. And rejecting MW band better? You could roll your own Passive High Pass Filter, http://www.learningaboutelectronics.com/Articles/High-pass-filter-calculator.php#answer2 Try 820 Ohms for the resistor, and 100pF for the capacitor. The FREQ Cutoff on that site calculator is 1.942MHz, so anything above that should pass through, while anything below that should be attenuated. If anything, it's neat to try.