Electronics Illustrated had an article in 1968 (?)
The transmitter was built on a piece of wood.
It was called the Bare Essentials Transmitter and
used one 50C5 tube and a bunch of other parts.
It was a very dangerous circuit because it had no
power transformer. Also, it was very prone to bad
VHF parasitics. I built one for 80 meters and my
good ham friend built one of for 40.
When I keyed mine on 80 meters the TV set in the
next room would get bad interference. Local channel
3 would get blocked. The TV screen would turn black.
What state are you in Miles? My 2 watt 80 meter signal
doesn't get very far, but my ham friend in New Jersey can
hear it OK. Are you not too far from Connecticut? We have
generally been on 3560 kHz around 11:30 PM local EST.
By the way, the guy who wrote the original article was
W5LET. He's not alive anymore, but the article is
easily found by Google.
Best Wishes,
Bruce, MICRO1690/1700
You know, I think that's the article I'm thinking of. My QRP TX is the Tuna Tin 2, on a bread board.
I'm in Cuyahoga Falls, Ohio, between Akron and Cleveland, the name is Bob.
I don't have an 80 meter antenna up but I do have a random wire and home brew tuner that might do. Right now I only have the driven element from an old TH3 tri-bander, 10/15/20 mtr. It's hanging off the side of my tower at about 25 feet, favoring east/west directions.
I'll load up the wire and give a listen some time.
I also have a Tuna Tin 2!
When I built it, my kids were really young.
I knew it might get damaged if they were
playing around the ham shack. So I put it
into a Radio Shack project box and just for
fun, I put two LEDs on the front. One LED
lights up green as soon as the TT2 is connected
to power. The other LED lights up red when
the TT2 is keyed.
I bought the kit from the New Jersey QRP club
around 1999. I just checked the other day -
it puts out 400 mW and the keying still sounds
fine. The power connector on the back of the
enclosure is loose, though, and I have to replace it.
The 6AQ5 transmitter only puts out 2 or 3 watts,
but you never know, you might hear it if conditions
are right.
I am now in West Hartford, Connecticut. I have a K1
callsign. I would give my whole callsign, but
(and maybe I'm a little off base here) I would like to
be somewhat anonymous. I read somewhere that
some of the royalty licensing companies were trying
to figure out where Part 15 stations are located. Maybe
they are looking at this board?
Again, maybe I'm being too cautious, I guess I'm a little
confused with that issue.
Best Wishes,
Bruce, MICRO1690/1700
Bruce, you've confused me by talking about communicating on amateur radio equipment while worrying that the royalty hawks are searching for part 15ers. Why would royalty spies be watching amateur radio frequencies?
My ham radio callsign gives my address.
Would the royalty hawks be interested in
that info? (Concerning my Part 15 station.)
I think some people wonder about this. But I
may be way way off base here. Especially
since my station isn't even on the air except
in my house.
By the way, I like all you guys and wish you could
all come over to my house for pizza. (Seriously.)
Best Wishes
Bruce, MICRO1690/1700
P.S. Concerning my disability, I have
been shafted by the system a bunch
of times. This may be affecting my
judgment.
In my first post in this thread I mentioned that my part 15 signal overloaded the AVC and I had to operate on manual gain control. This was disappointing since in manual mode the S meter is disabled and there is something magic about seeing the meter deflection with a signal. Sort of makes it seem as if I am receiving a real radio signal plus it enables me to fine tune my transmit antenna loading system. So my task was to get the receiver to work in automatic gain mode with the meter on.
I tried a 1 inch antenna, no dice. Tried no antenna, no dice. Tried shorting both antenna terminals to chassis gnd. No signal. The receiver is well shielded in a metal cabinet.
Then I remembered that I have a small loop antenna attached to the back of a retired amplifier/tuner. This loop is designed to attach to a differential antenna input such as is on my receiver so I hooked it up. Success! By orienting the loop I can receive my signal with no overloading and the S meter deflects nearly full scale depending on how I orient the loop. I can also receive other stations without changing the antenna connection, only by changing the loop orientation. This also allows me to pull in stations despite the very high electrical noise level in my house (my wife loves light dimmers and touch switch lamps which are everywhere around here).
Though the loop is small, measuring 6 by 3 inches, it is adequate given the sensitivity of the receiver. The loop is almost immune to the dimmer hash.
If you have a receiver with a differential (balanced) antenna input you will probably be very pleased with the performance of a loop antenna.
Neil
I once had what I thought might have been a great shortwave radio, at the time i was about 18 years old living in Medina Ohio and my dad got a job in Cincinnati Ohio so some things were left behind with a friend.
My tube receiver along with two military receivers and assorted stuff was put into storage at a friends house. After reading about all the great radio you guys have, i would love to get my hands on those radio's i left behind so long ago. I have the sick feeling they are lost forever.
I am not even sure what the brand or model number of the tube shortwave was, but i can explain it a bit here from memory.
All metal case (big surprise) to the left a large dial with one long needle to point at frequencies silkscreened onto the face of the dial.
A few other knobs such as the tuning knob was to the right between the speaker and tuning dial, that knob was plastic while the rest of the knobs were metal .One knob selected bands, another volume. There was a head phone jack and a couple other knobs i cannot remember what they were for.
The back was partially open so you could reach in the back and get a good shock if you needed to wake up real fast lol. Below that opening was power cord, i believe there was a so-239 connector and two screws for twin lead wire antenna.
I never had the chance to see if the radio worked and still to this day never knew what company made this radio.
Maybe I need to put in a call to my parents and see if that radio can be located. By the way the case was kind of gray in color.
Oh well there's my story and it's good to be back.
Take Care
p.s. Anyone want some snow lol
The top cover was vented with many small holes
It was 1977 and I was running a lonely little gas dock up in Bristol Bay, AK during the Salmon season. Any kind of personal entertainment was very hard to come by - TV consisted of 2 hours a day from a far away military base, Walkmans and VCRs were strange devices rumored to be in Japan, there were no FM broadcasts and even AM wasn't really tunable, it seemed like nothing bounced up (or out) that far.
While searching the Quonset huts we used for storage, looking for a missing valve handle, I spied two silver grey radio cases on a shelf at the back of a closet. Being a radio freak even then, I grabbed the radios and took them back to my bunkhouse room for further investigation.
I had discovered two identical compact, early 60s table-top shortwave receivers!
Having already been a bit of an electronics nut, I examined the units carefully before powering up either one. The first unit I looked at had obvious capacitor problems with a swollen can and a couple of drippy cardboard electrolytics - probably a no-go. The second looked much better, with no obvious issues. I powered up #2 and got a little bit of hum, but no joy.
Going with what I had, I started exchanging tubes, one at a time, between #1 and #2. Swap, power, nothing. Swap, power, nothing, swap, power... YES! The unmistakable sizzle of a shortwave receiver tumbled out of the speaker! I grabbed a long chunk of Romex that was in one of the dump boxes and attached one of the leads to to the antenna terminal and laid the Romex out on the floor.
After a short band scan I heard the unmistakable "click, click, click, BONG - at the tone, 21 hours, 37 minutes, coordinated universal time" down at 5 MHz and I was in business. For the rest of the summer I was entertained by everything from Australian jazz to Soviet propaganda to Deutche Welle and our position "at the top of the world" provided good reception at all hours.
1977 - Probably close to the halcyon of the shortwave era, and what a blast to sit out in the middle of the Naknek river and tune the world!
What I can't remember after all these years was the brand - I'm sure it will come to me and I'll update when it does.
UPDATE: Found it online - they were Hallicrafters S-38Es
My father having been "over there" during WWII always had a shortwave set, including the big old tube version of Zenith Transoceanic, and I'd tune around finding so much to listen to that it seemed like life could never be long enough. Loved Radio Nederland and Swiss Broadcasting Service and BBC. Also WWV was interesting with the time pulses and a guy I worked with at a radio network in the 70s told me that back in the 1940s CBS and NBC had shortwave transmitter farms putting the networks on for armed forces around the world.
One show I loved was the "Happy Station" from Radio Nederland, featuring totally friendly English banter and delightful music from every country, a true work of international friendship. Now a guy named Keith Perron who worked back at the station has purchased the rights to "Happy Station" and offers re-broadcast to anyone who contacts him at pcjmedia.com. He also does a lot of shortwave related projects and has a lot of the old gang from the shortwave stations appear as his friends.
Now with shortwave having been all but abandoned, I like to think there will be relaxed rules allowing more part 15 type limited power stations so we will have our turn to play the world.
Now that things have settled down a bit and my transmitter and receiver are stable I took some time to measure the frequency response from the input to the transmitter to the output of the receiver. The midband level was adjusted so the transmitter (SSTRAN) compression was not active and the receiver bandwidth was set to 16 kHz.
The results are:
3 dB bandwidth: 50 to 11150 Hz.
Passband gain: Flat within +/- 1 dB.
No wonder the audio sounds so good! These numbers reflect the performance of both the receiver and transmitter and together they give very good results.
If time permits I will try to separate the response so the transmitter performance and the receiver performance can be seen individually.
P.S. Enjoyed the stories about other old radios. Keep them coming.
Neil
Very neat way to monitor your signal's clarity etc etc etc....with a bunch of variable controls to "make" it sound clean, clear etc etc etc. :/
This does not mean your TX signal is in fact sending out the way your "adjusted by ear" antique receiver is making it sound like.
Remember, 99.9999 percent of the radios being used to pick up your flea powered TX does not have all those adjustments to play with.
I noticed many here are or were HAM operators. Why not BUILD a proper modulation monitor eh? One without any AGC or AVC or ABW???
Pretty easy to do....and can be done with junk parts....and I know most hams either know someone with calibrated test gear or have access to those so their home made modulation monitor can be calibrated....perhaps not 100 percent accurate but FAR more accurate and FAR better than just tweaking some old antique receiver's adjustments till you hear the signal clean up. (lol).
Don't get me wrong here, I think its great someone is putting that old thing to some use besides being the household dust collector. But for using to check one's modulation purity well.....considering the alternatives available with far more accurate results and REAL results....I think the old gal radio is better served sitting in the corner for a conversation piece while its playing your station....AFTER its been checked by more accurate and reliable test gear! :)))
RFB
Quoting RFBurns: Why not BUILD a proper modulation monitor eh? One without any AGC or AVC or ABW???
What you have no way of knowing is that I have previously checked the transmitter using a scope displaying a trapezoidal pattern. This was done to check linearity and phase distortion and also was used to calibrate a VU meter with which I monitor the audio into the transmitter.
As you probably well know, measuring the frequency response as I did does not assess the fidelity of the signal and neither does measuring modulaiton. That was not my intent. It was simply a means to check the frequency response. My comment about "no wonder it sounds so good" was certainly subjective and was based on the belief that good frequency response is a prerequisite to good fidelity.
In an attempt to be objective, I have also measured the THD of the received signal on another receiver and though it doesn't directly assess the transmitter performance since it includes distortion from the receiver it does give a limit on the distortion which would be produced by the transmitter. Since I observed that the THD changed quite a bit with the receiver volume setting I didn't report the numbers since they were not representative of the isolated transmitter effects. They were consistent with the data sheet numbers for IC audio amplifiers commonly used in low cost receivers however.
My approach is one which is typical in instrumentation where the system is verified and periodically checked rather than monitored continuously. Your suggestion of a modulation monitor is certainly with merit but it is not worth my time and effort for what I am doing.
The "old gal" receiver is being used for my own listening enjoyment and part of this is to do my best to produce a clean signal. Though, as you correctly point out, there are better ways to monitor or check a signal. I suspect that if there is a problem with my system I will notice it with the "old gal" pretty quickly.
Neil
First of all, the stories are wonderful.
I could comment on
all of them. I was really cool seeing the pictures
of the S-38E, which is so much different looking
than the S-38.
In 1962, when I was 7 or 8, my dad built a Heathkit
CR-1.
I still have it - it is a cool little crystal set, which I
believe was intended to be a bomb shelter radio
during the cold war era. It was made from the 1950s
until sometime in the 1960s, I guess.
It is easy to find on the web, but basically it is a
box with 3 knobs for tuning, and binding posts
for 2000 ohm headphones, antenna and ground.
When I was a boy, but old enough to know what
a gem it was, my dad took it out
of the attic and let me have it.
It received the local stations. WDRC, Hartford on
1360 was my favorite, because it was a top 40 station at the
time. This was about 1968. WDRC's big competitor, WPOP
(1410) would appear under WDRC if I tuned the radio
correctly. I had no problem with listening to both stations
at once.
The radio had the old Conelrad markings on it (640 and 1240 kHz.)
Somewhere along the line I partly stripped the radio for the
tunable capacitors. Twenty years later, I put the radio
completely back together. Unfortunately, the original knobs
are gone. I had to use some other knobs that looked
similar.
Crystal radio DX? I had never believed it to be possible with
that radio. It was a nice crystal set, but so many people have
designed DX crystal sets are greatly superior. The
CR-1 is just not that selective.
Well, with a 150 foot end fed wire, I did get a few DX stations.
I heard the weird Cuban time-tick station on 570 kHz. (This
station transmits on frequencies all over the AM BCB, as
many of you know.) I also heard the Canadian 740 kHz oldies
station. (I thinks it's in Toronto.)
During the day, WFAN (ex WNBC) on 660 kHz in New York city is there
most of the time. The radio has received some other stations,
but the above mentioned ones are probably the
most interesting.
It is possible to DX on this radio below about 750 kHz. Anywhere
above that, the local stations swamp the set, especially WTIC
(1080 kHz 50 kW), three miles away. I have tried to build wave traps
to knock down the local stations, but so far I have been unsuccessful.
WTIC AM is transmitting with HD IBOC, and it is very easy to
hear the IBOC hash just to the sides of the AM audio.
Some day, I want to build a really good crystal set.
Best Wishes,
Bruce, MICRO1690/1700