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Re: Regenerative Detector Ecology

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  • Gary
    I used a TR switch that acted as a manual ACR, when in receive condx, the receiver input was grounded, which for standing side by side with an era MOPA
    Message 1 of 14 , Jul 1, 2010
      I used a TR switch that acted as a manual ACR, when in receive condx, the receiver input was grounded, which for standing side by side with an era MOPA operating abt 35w. was actually fairly tolerable, and using a 3w PO was actually pleasant. But the thing I noticed was that no matter how I may have duplicated a receiver, each was a real individual. Twinplexer "A" may have worked well this way. Supposed duplicate Twinplexer "B" may crawl off the table unless you made that TR switch a double, simultaneously disabling the first audio stage or switching in a resistor at some part of the audio chain. And then you may have to heavily cap the switch itself to keep the popping of the switch when you flip it from being worse than the clicking of the rig itself. Heh, the switch itself becomes a more complicated mess than the receiver :>)

      Another thing was to let the rig swamp with the regen turned to minimum and use random hum as a sort of side-tone. Just as random. But that was sort of the charm of wireless communications for the Yeoman of the '20s and 30s. So much was off the cuff. And these obstacles were taken for granted.

      -gary / wd4nka

      --- In regenrx@yahoogroups.com, "davidpnewkirk" <david.newkirk@...> wrote:
      >
      > [I first posted this earlier today as part of a regenerative receiver thread in the EMRFD (Experimental Methods in RF Design) Yahoo group:]
      >
      > If we're going to use a regenerative detector on the receiving end of two-way communication, we must also consider, and design for, its ecology--that is, how it interoperates and interacts with other parts of the communication system. A challenging aspect of that ecology involves using the regenerative receiver to accurately and comfortably monitor the transmitted signal. During Morse code operation, this is especially challenging because, as a result of an oscillating regenerative detector's tendency to be "pulled" toward the frequency of CW signals received at a practically low pitch, the transmitted signal level at the detector must be reduced many tens of decibels to avoid pulling during reception of the local transmitter. (Related problem: How does one accurately--without frequency shift--*and* sufficiently reduce the output of a "simple" single-device Morse code transmitter for spotting such that the receiver is not overloaded? Extra credit: No receiver gain-reduction allowed during spotting; we'd like that spotting signal to sound no louder than a moderately strong, on-air signal right alongside on-air signals. Further extra credit: Make the spotting level at least moderately adjustable. But I digress. :-D)
      >
      > On paper, the problem looks basic: During transmission, we need merely insert a large negative gain between the detector and antenna (and perhaps some between the detector and speaker/headphones, maybe adjustable to provide an adjustable monitoring level. In practice, especially with a regenerative detector operating at signal frequency (as opposed to one operating at an IF, which technique allows us to much more easily reduce pre-detector gain by reducing frequency-conversion gain one way or another), achieving enough isolation to avoid detector pulling and/or overload is *tough*. The isolation necessary/achievable may even vary with the band and with the load (dummy antenna or antenna--and *which* antenna?). And then one day you decide to go QRO [higher power] instead of QRP [lower power] and it's back to the drawing board.
      >
      > Literature from yesterday doesn't help: Common ham practice during the regenerative-receiver era was to use separate transmitting and receiving antennas (the receiving antenna, often just a random wire, commonly quite short) and no TR [transmit-receive] switching; old-timers generally just let their detectors overload, perhaps pushing their headphones forward off their ears to make the resulting clacks and bangs less deafening.
      >
      > So a simple regenerative receiver can turn out to present practical problems that turn out to be not so simple.
      >
      > Best regards,
      >
      > Dave
      > amateur radio W9VES
      > http://mysite.verizon.net/dpnewkirk/ej/
      >
    • afelino
      My 1928 ARRL Handbook has, like later versions, a chapter on receivers and a chapter on transmitters, but in between there is a chapter on monitors. A
      Message 2 of 14 , Jul 1, 2010
        My 1928 ARRL Handbook has, like later versions, a chapter on receivers and a chapter on transmitters, but in between there is a chapter on monitors. A well-equipped 1928 station basically consisted of three oscillators, one acting as a receiver, another as a transmitter and the third used as a oscillator that could be placed on the same frequency as the transmitter/antenna combination by listening for zero beat in attached headphones, then subsequently used as a low-level signal to match frequencies with the regenerative receiver/antenna combination. The monitor was shielded and not connected to an antenna. It was frequency calibrated against known (usually Navy) stations and served as the frequency reference for the station. Presumably, it could even provide transmit sidetone.

        From the same era are references to making antenna changeover relays from old telegraph sounders, so the idea was not unknown. The above system would work the same with either separate or switched antennas.

        A few years ago I routinely operated with very simple regens (one FET, usually)and I spotted by keeping the antenna connected to the receiver while spotting. The transmitter used a DDS VFO that was coupled to a small wire sticking out the back of the VFO. This could be adjusted to provide just the right amount of leakage to the antenna so that the regen was not overloaded. It also provided accurate frequency readout. In transmit mode the phones were disconnected from the receiver (which, for the simplest receivers actually removed power completely.) All this switching was handled by relays so it was pretty convenient. This works because unlike the 1928 case, my DDS doesn't change frequency when hooked to the antenna and the rest of the transmitter.

        Now I sometimes use my FT-817 as a transmitter and use a wire near the regen (switched to the antenna) to couple into the 817 reciever for zero beating. All can be switched by relays, of course.

        73, af wn6q

        --- In regenrx@yahoogroups.com, "davidpnewkirk" <david.newkirk@...> wrote:
        >
        > [I first posted this earlier today as part of a regenerative receiver thread in the EMRFD (Experimental Methods in RF Design) Yahoo group:]
        >
        > If we're going to use a regenerative detector on the receiving end of two-way communication, we must also consider, and design for, its ecology--that is, how it interoperates and interacts with other parts of the communication system. A challenging aspect of that ecology involves using the regenerative receiver to accurately and comfortably monitor the transmitted signal. During Morse code operation, this is especially challenging because, as a result of an oscillating regenerative detector's tendency to be "pulled" toward the frequency of CW signals received at a practically low pitch, the transmitted signal level at the detector must be reduced many tens of decibels to avoid pulling during reception of the local transmitter. (Related problem: How does one accurately--without frequency shift--*and* sufficiently reduce the output of a "simple" single-device Morse code transmitter for spotting such that the receiver is not overloaded? Extra credit: No receiver gain-reduction allowed during spotting; we'd like that spotting signal to sound no louder than a moderately strong, on-air signal right alongside on-air signals. Further extra credit: Make the spotting level at least moderately adjustable. But I digress. :-D)
        >
        > On paper, the problem looks basic: During transmission, we need merely insert a large negative gain between the detector and antenna (and perhaps some between the detector and speaker/headphones, maybe adjustable to provide an adjustable monitoring level. In practice, especially with a regenerative detector operating at signal frequency (as opposed to one operating at an IF, which technique allows us to much more easily reduce pre-detector gain by reducing frequency-conversion gain one way or another), achieving enough isolation to avoid detector pulling and/or overload is *tough*. The isolation necessary/achievable may even vary with the band and with the load (dummy antenna or antenna--and *which* antenna?). And then one day you decide to go QRO [higher power] instead of QRP [lower power] and it's back to the drawing board.
        >
        > Literature from yesterday doesn't help: Common ham practice during the regenerative-receiver era was to use separate transmitting and receiving antennas (the receiving antenna, often just a random wire, commonly quite short) and no TR [transmit-receive] switching; old-timers generally just let their detectors overload, perhaps pushing their headphones forward off their ears to make the resulting clacks and bangs less deafening.
        >
        > So a simple regenerative receiver can turn out to present practical problems that turn out to be not so simple.
        >
        > Best regards,
        >
        > Dave
        > amateur radio W9VES
        > http://mysite.verizon.net/dpnewkirk/ej/
        >
      • pappy_hiram
        Ac or DC relays? Pappy Hiram
        Message 3 of 14 , Jul 1, 2010
          Ac or DC relays?

          Pappy Hiram


          --- In regenrx@yahoogroups.com, "afelino" <wn6q@...> wrote:
          >
          > My 1928 ARRL Handbook has, like later versions, a chapter on receivers and a chapter on transmitters, but in between there is a chapter on monitors. A well-equipped 1928 station basically consisted of three oscillators, one acting as a receiver, another as a transmitter and the third used as a oscillator that could be placed on the same frequency as the transmitter/antenna combination by listening for zero beat in attached headphones, then subsequently used as a low-level signal to match frequencies with the regenerative receiver/antenna combination. The monitor was shielded and not connected to an antenna. It was frequency calibrated against known (usually Navy) stations and served as the frequency reference for the station. Presumably, it could even provide transmit sidetone.
          >
          > From the same era are references to making antenna changeover relays from old telegraph sounders, so the idea was not unknown. The above system would work the same with either separate or switched antennas.
          >
          > A few years ago I routinely operated with very simple regens (one FET, usually)and I spotted by keeping the antenna connected to the receiver while spotting. The transmitter used a DDS VFO that was coupled to a small wire sticking out the back of the VFO. This could be adjusted to provide just the right amount of leakage to the antenna so that the regen was not overloaded. It also provided accurate frequency readout. In transmit mode the phones were disconnected from the receiver (which, for the simplest receivers actually removed power completely.) All this switching was handled by relays so it was pretty convenient. This works because unlike the 1928 case, my DDS doesn't change frequency when hooked to the antenna and the rest of the transmitter.
          >
          > Now I sometimes use my FT-817 as a transmitter and use a wire near the regen (switched to the antenna) to couple into the 817 reciever for zero beating. All can be switched by relays, of course.
          >
          > 73, af wn6q
          >
          > --- In regenrx@yahoogroups.com, "davidpnewkirk" <david.newkirk@> wrote:
          > >
          > > [I first posted this earlier today as part of a regenerative receiver thread in the EMRFD (Experimental Methods in RF Design) Yahoo group:]
          > >
          > > If we're going to use a regenerative detector on the receiving end of two-way communication, we must also consider, and design for, its ecology--that is, how it interoperates and interacts with other parts of the communication system. A challenging aspect of that ecology involves using the regenerative receiver to accurately and comfortably monitor the transmitted signal. During Morse code operation, this is especially challenging because, as a result of an oscillating regenerative detector's tendency to be "pulled" toward the frequency of CW signals received at a practically low pitch, the transmitted signal level at the detector must be reduced many tens of decibels to avoid pulling during reception of the local transmitter. (Related problem: How does one accurately--without frequency shift--*and* sufficiently reduce the output of a "simple" single-device Morse code transmitter for spotting such that the receiver is not overloaded? Extra credit: No receiver gain-reduction allowed during spotting; we'd like that spotting signal to sound no louder than a moderately strong, on-air signal right alongside on-air signals. Further extra credit: Make the spotting level at least moderately adjustable. But I digress. :-D)
          > >
          > > On paper, the problem looks basic: During transmission, we need merely insert a large negative gain between the detector and antenna (and perhaps some between the detector and speaker/headphones, maybe adjustable to provide an adjustable monitoring level. In practice, especially with a regenerative detector operating at signal frequency (as opposed to one operating at an IF, which technique allows us to much more easily reduce pre-detector gain by reducing frequency-conversion gain one way or another), achieving enough isolation to avoid detector pulling and/or overload is *tough*. The isolation necessary/achievable may even vary with the band and with the load (dummy antenna or antenna--and *which* antenna?). And then one day you decide to go QRO [higher power] instead of QRP [lower power] and it's back to the drawing board.
          > >
          > > Literature from yesterday doesn't help: Common ham practice during the regenerative-receiver era was to use separate transmitting and receiving antennas (the receiving antenna, often just a random wire, commonly quite short) and no TR [transmit-receive] switching; old-timers generally just let their detectors overload, perhaps pushing their headphones forward off their ears to make the resulting clacks and bangs less deafening.
          > >
          > > So a simple regenerative receiver can turn out to present practical problems that turn out to be not so simple.
          > >
          > > Best regards,
          > >
          > > Dave
          > > amateur radio W9VES
          > > http://mysite.verizon.net/dpnewkirk/ej/
          > >
          >
        • Paul W. Ross
          As to relays, when I did this many moons ago, I used a DPDT AC relay (110 volts). One pole to switch the antenna, the other to switch B+, IIRC. For 2 meters, I
          Message 4 of 14 , Jul 2, 2010
            As to relays, when I did this many moons ago, I used a DPDT AC relay
            (110 volts). One pole to switch the antenna, the other to switch B+,
            IIRC. For 2 meters, I had a nice coaxial relay, also at 110 VAC. Just a
            "railroad" relay for 6 meters and below.

            /paul W3FIS
          • davidpnewkirk
            ... Excellent. Yes, a transfer oscillator is a good outside the box practical approach to solving both problems--monitoring and spotting--simultaneously
            Message 5 of 14 , Jul 2, 2010
              --- In regenrx@yahoogroups.com, "afelino" <wn6q@...> wrote:

              > My 1928 ARRL Handbook has, like later versions, a chapter on
              > receivers and a chapter on transmitters, but in between there is a
              > chapter on monitors. A well-equipped 1928 station basically
              > consisted of three oscillators, one acting as a receiver, another
              > as a transmitter and the third used as a oscillator that could be
              > placed on the same frequency as the transmitter/antenna
              > combination by listening for zero beat in attached headphones,
              > then subsequently used as a low-level signal to match frequencies
              > with the regenerative receiver/antenna combination. The monitor was
              > shielded and not connected to an antenna. It was frequency
              > calibrated against known (usually Navy) stations and served as the
              > frequency reference for the station. Presumably, it could even
              > provide transmit sidetone.

              Excellent. Yes, a transfer oscillator is a good "outside the box" practical approach to solving both problems--monitoring and spotting--simultaneously without having to shield both transmitter and receiver with techniques worthy of the likes of Rohde and Schwarz. In the heyday of amateur use of the regenerative detector, use of a monitor was less onerous than it might seem because before crystal control came into wide use, the LC-controlled transmit oscillators used by hams were generally brought "into the band" and frequency-adjusted relatively little thereafter. The practice of tuning one's transmitter to match the frequency of the other station did not become commonplace until the late 1930s (and was unavailable to Novice class hams for the first two decades or so of the availability of the Novice license); only net operation required both stations in contact to be on or close to the same frequency, and that was usually done by means of crystal control. (From the practice/need for net participants to be on the same frequency came the verb "net" as a synonym for "adjust to zero beat.") For awhile in the 30s, there were even special ham-coined Q signals (QMH, QLH, and so on) that signified "tuning from the low end up; tuning from the middle toward the high end," and so on, that you could send to (with luck) cue other operators in to where you might be listening.

              Comfortable, accurate spotting and monitoring with an oscillator-only transmitter and regenerative receiver *without* the use of a monitor makes a pleasant engineering challenge in the same way that comfortable full CW break-in (being able to hear the other station at full receive sensitivity between the dots and dashes of your own Morse code transmission) makes a pleasant engineering challenge. So common is well-implemented full break-in in modern factory-built ham transceivers nowadays--and so commonly did old-days ARRL publications harp on its necessity as a result of the CW- and traffic-handling bias of key ARRL HQ personnel back then--that we likely fail to discover through research that full break-in was essentially impossible in the *oldest* days of ham spark transmission because you couldn't hear anything but the whir of your rotary-gap motor once it was running, and anyway you'd fry your cat's-whisker (or, if you were well off, Audion) detector if you didn't disconnect it during transmission. That allows us to understand that full break-in is not a necessity but a confection.

              And so yes, comfortable spotting and monitoring with a regen and no monitor as opposed to throwing four switches and adjusting two controls between receive and transmit, and or pushing one's headphones forward onto one's temples to avoid deafness, is a technological confection in the same sense. As is sidetone (an audio tone that shadows every press of your key so you can hear your own sending) if you're using a straight key; but if you're sending with a bug or keyer (which completes dots and/or dashes for you), some sort of sidetone is a necessity. Sometimes even the groan of transmitter-power-supply transformer and/or choke laminations can serve!

              BTW, in my BG-3 receiver (http://mysite.verizon.net/dpnewkirk/ej/goodman_receiver/#bg-3, which is not yet updated to reflect my use of a 13DE7 cascoded-triodes synthetic tetrode detector) I'm now doing comfortable transmitted-CW monitoring by combining the result of:

              a) shorting the mixer grid to chassis with a miniature relay;

              b) shorting the hot end of the AF gain to chassis via a rheostat-connected 1-M potentiometer and another miniature relay;

              c) opening the cathode's of the set's 6U8A triode-pentode local-oscillator amplifier/cathode follower, augmented with

              d) optionally switch in or out a rheostat-connected 100-k pot between the opened 6U8A-cathodes connection and ground to allow setting a "less deaf" monitoring level for when I'm transmitting into a dummy antenna rather than an actual antenna. (Transmitting into my actual antenna, a backyard 100-foot-long ladder-wire-fed doublet 30 feet high, bathes the station and its connecting cables and wires with enough RF to make the default "leakage" level much stronger during use of the real antenna than with use of the dummy antenna. And this is with my 7- to 8-watts output homemade "Summer 40/Winter 80" transmitter/receiver; I'm hoping that when I next fire up my modified-for-transmit-only Heath HW-16 transceiver [about 30 W output, max] I'll have enough adjustment range to not have to reengineer these muting subsystems. :-))

              Through this arrangement I can hear my on-air transmitter signal, and my into-a-dummy-antenna transmitted signal, at comfortable, adjustable level with no pitch shift due to detector or LO load changes or overload.

              Best regards,

              Dave
              amateur radio W9VES
            • Bauman, John
              Dave W9VES, Thank you for the Amateur Radio history lesson! I appreciate, like many others, your insight in to past amateur practices and how we can learn form
              Message 6 of 14 , Jul 3, 2010
                Dave W9VES,
                Thank you for the Amateur Radio history lesson! I appreciate, like many others, your insight in to past amateur
                practices and how we can learn form them today. I've always shied away from using my vintage homebrew regens
                with simple homebrew transmitters because of the lack of side tone and/or muting issue. I'll look into building a simple
                monitoring receiver. It would be a kick to send "rig hr is PP Jones TX and Doerle regen"!

                John
                KB7NRN
              • Paul W. Ross
                As to not zero beating the other station, I did a lot of 6 and 2 meter AM in the 50s and 60s. The only way for any degree of stability was to use a crystal
                Message 7 of 14 , Jul 3, 2010
                  As to not "zero beating" the other station, I did a lot of 6 and 2 meter
                  AM in the 50s and 60s. The only way for any degree of stability was to
                  use a crystal oscillator. Thus, you called CQ and looked around for a
                  response.

                  73 /paul W3FIS
                • Gary
                  Any of y all remember working with an S38 Halli or similar, and rocking the receiver back and forth over the zero beat to find out which side you might be
                  Message 8 of 14 , Jul 3, 2010
                    Any of y'all remember working with an S38 Halli or similar, and rocking the receiver back and forth over the zero beat to find out which side you might be getting a response from? (Sigh) The Novice Days . . . ! Wouldn't trade 'em for anything.

                    -gary / wd4nka

                    --- In regenrx@yahoogroups.com, "Paul W. Ross" <deadgoose@...> wrote:
                    >
                    > As to not "zero beating" the other station, I did a lot of 6 and 2 meter
                    > AM in the 50s and 60s. The only way for any degree of stability was to
                    > use a crystal oscillator. Thus, you called CQ and looked around for a
                    > response.
                    >
                    > 73 /paul W3FIS
                    >
                  • W3FIS
                    I had a Hallicrafters S-20R with a Heathkit Q multiplier, which was essentially a regenerative IF, which gave me seriously narrow bandwidth! I later moved to
                    Message 9 of 14 , Jul 3, 2010
                      I had a Hallicrafters S-20R with a Heathkit "Q" multiplier, which was essentially a regenerative IF, which gave me seriously narrow bandwidth!

                      I later moved to ARC-5 receivers, using them as a "back end" to crystal converters for 6 and 2 meters.

                      /paul W3FIS
                    • kyoritsu
                      Gary, I remember occasionally working stations that were so far away from my XTAL frequency that I couldn t monitor my own CW. I also remember the bedlam that
                      Message 10 of 14 , Jul 3, 2010
                        Gary, I remember occasionally working stations that were so far away from my XTAL frequency that I couldn't monitor my own CW. I also remember the bedlam that the 40 meter novice band was in 1963: even if you could have used a VFO then, there was no empty place to sit and send. I learned I had to get up in the middle of the night to be able to work anyone, which of course turned out to be an unexpected blessing. It was really exciting to hear and even occasionally work a W5, 6, or 7. Especially a W7, that was exotic DX for me, in northern NJ.

                        I remember those young novices occasionally featured in the Popular Electronics ham radio column, the teens with the great rigs, and the amazing stories: 'Believe it or not, young Tom, WN2XXX, has worked more countries (22) than states (20) in his first week on the air. Tom credits his 75A4, Johnson Valiant, and 5 element 15 meter beam.' I used to envy those guys, but now I realize they never knew the thrill of working North Dakota at 2am with a slightly gassy and very, very hot 6L6G.

                        Also remember I started to feel like a grizzled OT after having my novice license 5 months: I was wn2jwa, and there were these new recruits, wn2L..., even wn2M... appearing. You knew them from their slow, shaky fists, they way they repeated their callsigns three times even after the QSO had started, and especially by the use of punctuation instead of the BT. (I have to confess I used not only periods in my first QSOs, but also commas, colons and semi-colons, apostrophes, quotations marks, and exclamations mark until someone set me right). I got my General class, did other stuff, but somehow it wasn't quite the same.

                        Yes, indeed, SIGH.

                        Rob

                        --- In regenrx@yahoogroups.com, "Gary" <wd4nka@...> wrote:
                        >
                        > Any of y'all remember working with an S38 Halli or similar, and rocking the receiver back and forth over the zero beat to find out which side you might be getting a response from? (Sigh) The Novice Days . . . ! Wouldn't trade 'em for anything.
                        >
                        > -gary / wd4nka
                        >
                      • Pronto. (Military)
                        I too remember using a very hot 6L6 so another Ham turned it over and put it upside down in a tin can of oil to help it run cool. Jim VE3DDY
                        Message 11 of 14 , Jul 4, 2010
                          I too remember using a very hot 6L6 so another Ham turned it over and put it upside down in a tin can of oil to help it run cool.
                          Jim VE3DDY

                          --- In regenrx@yahoogroups.com, "kyoritsu" <rikkyograsing@...> wrote:
                          >
                          > Gary, I remember occasionally working stations that were so far away from my XTAL frequency that I couldn't monitor my own CW. I also remember the bedlam that the 40 meter novice band was in 1963: even if you could have used a VFO then, there was no empty place to sit and send. I learned I had to get up in the middle of the night to be able to work anyone, which of course turned out to be an unexpected blessing. It was really exciting to hear and even occasionally work a W5, 6, or 7. Especially a W7, that was exotic DX for me, in northern NJ.
                          >
                          > I remember those young novices occasionally featured in the Popular Electronics ham radio column, the teens with the great rigs, and the amazing stories: 'Believe it or not, young Tom, WN2XXX, has worked more countries (22) than states (20) in his first week on the air. Tom credits his 75A4, Johnson Valiant, and 5 element 15 meter beam.' I used to envy those guys, but now I realize they never knew the thrill of working North Dakota at 2am with a slightly gassy and very, very hot 6L6G.
                          >
                          > Also remember I started to feel like a grizzled OT after having my novice license 5 months: I was wn2jwa, and there were these new recruits, wn2L..., even wn2M... appearing. You knew them from their slow, shaky fists, they way they repeated their callsigns three times even after the QSO had started, and especially by the use of punctuation instead of the BT. (I have to confess I used not only periods in my first QSOs, but also commas, colons and semi-colons, apostrophes, quotations marks, and exclamations mark until someone set me right). I got my General class, did other stuff, but somehow it wasn't quite the same.
                          >
                          > Yes, indeed, SIGH.
                          >
                          > Rob
                          >
                          > --- In regenrx@yahoogroups.com, "Gary" <wd4nka@> wrote:
                          > >
                          > > Any of y'all remember working with an S38 Halli or similar, and rocking the receiver back and forth over the zero beat to find out which side you might be getting a response from? (Sigh) The Novice Days . . . ! Wouldn't trade 'em for anything.
                          > >
                          > > -gary / wd4nka
                          > >
                          >
                        • davidpnewkirk
                          ... Yes--as I did with by BG-3 superhet-regen just two nights ago when working K4JYS on 80. The transmitter I m using at moment begins with solid-state 3.5-MHz
                          Message 12 of 14 , Jul 4, 2010
                            --- In regenrx@yahoogroups.com, "Gary" <wd4nka@...> wrote:

                            > Any of y'all remember working with an S38 Halli or similar,
                            > and rocking the receiver back and forth over the zero beat to
                            > find out which side you might be getting a response from? (Sigh)
                            > The Novice Days . . . ! Wouldn't trade 'em for anything.

                            Yes--as I did with by BG-3 superhet-regen just two nights ago when working K4JYS on 80. The transmitter I'm using at moment begins with solid-state 3.5-MHz VFO built from/into a BC-459 transmitter hulk, and continues with a 12AL11-1631 transmitter (the "Summer40/Winter80") built into a s'mores cookie tin augmented by two International Coffee cans. All I did to make the BC-459 tank cover 80 was trim it down with loads of capacitance until its coverage straddled 3500-3600 kHz (actually, up to about 3695). That makes for a nice slow tuning rate, but because the BG-3 does not do single-signal reception (you can hear "both sides of zero beat"), when zero-beating my VFO to incoming signals I must bring the BC-459 to the same pitch and then rock the BG-3 tuning a smidge to make sure both signals vary pitch in the direction. When zero-beating JYS--who was using an HQ-150 and Lysco Bandmaster transmitter at 30 W output, BTW--I tuned the BC-459 VFO to the wrong side on the first try.

                            A brief description of my first-ever QSO appears in an essay I wrote for a local ham newsletter in 1992: "Farewell to Monrovia" ( http://mysite.verizon.net/dpnewkirk/ej/farewell_to_monrovia.htm ). That writeup doesn't mention the hardware: A Lettine 240 transmitter (I had to change crystals with a pair of gas pliers and a flashlight because the crystal socket, an octal tube socket between the crystal oscillator tube [6L6GB] and a cabinet side, was in the dark at any time of day and I didn't want to burn my hand on the 6L6) and a National NC-100X receiver preceded by a tunable converter built into two soldered-together-sideways-like-bongos Price Albert tobacco cans by my father, amateur radio W9BRD. (The converter a variation on "The HF Gem" relayed in the Radio Society of Great Britain's "Technical Topics" column in the early 1960s] that had a 12.25-12.5 MHz local oscillator [tuned via a backlit National BM dial--way cool with the lights out!] and plug-in front-end coil.) I'd tune the NC-100 to the 5.1 MHz and leave it there to receive the 40-meter Novice band by tuning the Prince Albert cans converter, improving the system's image rejection and gain by turning up the feedback in the converter's regenerative first mixer to just short of oscillation.

                            To this day I like to have stuff to rock and repeak while receiving; the BG-3 is a feast in this sense because it includes input and LO-buffer tuning adjustments in addition to regeneration and AF and RF gain controls. Oh, and two transmit monitor level controls... :-D

                            Best regards,

                            Dave
                            amateur radio W9VES
                          • Gary
                            Heh, I remember the first time I made a 6j7 / 6C5 xtal converter for my BC453. In fact, I still have those 6700 and 6900 kc Texas xtals somewhere . . . gave
                            Message 13 of 14 , Jul 4, 2010
                              Heh, I remember the first time I made a 6j7 / 6C5 xtal converter
                              for my BC453. In fact, I still have those 6700 and 6900 kc Texas xtals somewhere . . . gave me full coverage of 40. And you could
                              tell by the dial face where 7125 was . . . for a long time it was my ONLY xtal.

                              Then I started to catch a fairly loud birdie from the commercial marine station NMR. As nice and rhythmic it's call was, it definitely was an intruder. So I made the converter regenerative a'la a 1937 QST article. Wow, I don't know which was better - the increased Q or the increased volume! The marine commercial dropped way under the noise, and I only had to set the audio gain about a quarter open for headset. Peaking was an art, but soon realised that I did not have to run the regeneration at full bore. That rig stood toe to toe with my later Drake 2a for many, many years. Single signal filtering it was. Set for lower side.

                              I've long since sold her, and actually, I've gotten rid of all my rigs and equipment for the sake of my Letterpress Studio, but I did hang on to my smaller Regenerodyne and I have my HRO 5aT awaiting recapping. And I'll be back on the air with another 6AG7 / 6L6G or 807 xtal rig and that R-dyne and HRO soon enough. Kept some xtals, y'know. Nice you know ya can just build up another rig. I think the FCC still lets hams do that, don't they?


                              -gary / wd4nka
                              Q5 Studio & Pretty Good Letterpress
                              www.gjohanson.blogspot.com



                              --- In regenrx@yahoogroups.com, "davidpnewkirk" <david.newkirk@...> wrote:
                              >
                              > --- In regenrx@yahoogroups.com, "Gary" <wd4nka@> wrote:
                              >
                              > > Any of y'all remember working with an S38 Halli or similar,
                              > > and rocking the receiver back and forth over the zero beat to
                              > > find out which side you might be getting a response from? (Sigh)
                              > > The Novice Days . . . ! Wouldn't trade 'em for anything.
                              >
                              > Yes--as I did with by BG-3 superhet-regen just two nights ago when working K4JYS on 80. The transmitter I'm using at moment begins with solid-state 3.5-MHz VFO built from/into a BC-459 transmitter hulk, and continues with a 12AL11-1631 transmitter (the "Summer40/Winter80") built into a s'mores cookie tin augmented by two International Coffee cans. All I did to make the BC-459 tank cover 80 was trim it down with loads of capacitance until its coverage straddled 3500-3600 kHz (actually, up to about 3695). That makes for a nice slow tuning rate, but because the BG-3 does not do single-signal reception (you can hear "both sides of zero beat"), when zero-beating my VFO to incoming signals I must bring the BC-459 to the same pitch and then rock the BG-3 tuning a smidge to make sure both signals vary pitch in the direction. When zero-beating JYS--who was using an HQ-150 and Lysco Bandmaster transmitter at 30 W output, BTW--I tuned the BC-459 VFO to the wrong side on the first try.
                              >
                              > A brief description of my first-ever QSO appears in an essay I wrote for a local ham newsletter in 1992: "Farewell to Monrovia" ( http://mysite.verizon.net/dpnewkirk/ej/farewell_to_monrovia.htm ). That writeup doesn't mention the hardware: A Lettine 240 transmitter (I had to change crystals with a pair of gas pliers and a flashlight because the crystal socket, an octal tube socket between the crystal oscillator tube [6L6GB] and a cabinet side, was in the dark at any time of day and I didn't want to burn my hand on the 6L6) and a National NC-100X receiver preceded by a tunable converter built into two soldered-together-sideways-like-bongos Price Albert tobacco cans by my father, amateur radio W9BRD. (The converter a variation on "The HF Gem" relayed in the Radio Society of Great Britain's "Technical Topics" column in the early 1960s] that had a 12.25-12.5 MHz local oscillator [tuned via a backlit National BM dial--way cool with the lights out!] and plug-in front-end coil.) I'd tune the NC-100 to the 5.1 MHz and leave it there to receive the 40-meter Novice band by tuning the Prince Albert cans converter, improving the system's image rejection and gain by turning up the feedback in the converter's regenerative first mixer to just short of oscillation.
                              >
                              > To this day I like to have stuff to rock and repeak while receiving; the BG-3 is a feast in this sense because it includes input and LO-buffer tuning adjustments in addition to regeneration and AF and RF gain controls. Oh, and two transmit monitor level controls... :-D
                              >
                              > Best regards,
                              >
                              > Dave
                              > amateur radio W9VES
                              >
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