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QRP transmitter for Boatanchor receivers?
I've searched the web but haven't found the answer to my
QRP CW question. I'm looking for a QRP CW transmitter kit that includes QSK and will mute a boatanchor receiver like an SB-303, SX-101, or 75S-1. I realize that some receivers might not recover fast enough for QSK. I've looked at website ads for Ramsey, Vectronixs, and still don't have an answer. They might do it out of the box; they might do it with a mod but I haven't found the answer. A couple watts of CW and capable of working with the WA6OTP PTO kit. Anyone got something like that working? de ah6gi/4 -- |
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On Wed, 15 Dec 2004 15:51:26 UTC, (Scott Dorsey)
wrote: No Spam No wrote: I've searched the web but haven't found the answer to my QRP CW question. I'm looking for a QRP CW transmitter kit that includes QSK and will mute a boatanchor receiver like an SB-303, SX-101, or 75S-1. I realize that some receivers might not recover fast enough for QSK. I've looked at website ads for Ramsey, Vectronixs, and still don't have an answer. They might do it out of the box; they might do it with a mod but I haven't found the answer. A couple watts of CW and capable of working with the WA6OTP PTO kit. Anyone got something like that working? I have had great luck with a Heathkit signal generator into a key. BUT, if you want to get really fancy, check out the ARRL mobile manual, which has a really neat project transceiver. The transmitter section is based on a 1J6G and has an optional VFO. The TAB Book on ham radio projects also had a really neat one-tube transmitter that was hot chassis and built around the sweep tube. No VFO, though. Actually, plenty of VFOs out there put out enough power to be used as QRP rigs standalone. --scott thanks but not exactly what I'm looking for. I want something like a tuna-tin or peanut whistle QRP transmitter but with QSK TR and receiver muting. I'm not saying that the tuna-tin won't work. I don't know if it will or not. The web articles are not explicit on that point. I'd like 1 to 5 watts of clean CW produced by a solid state transmitter. Something that runs on a wall wart would be best. Crystal controlled would be OK but I've been looking at WA6OTP's website. He sells a PTO kit. Some folk have adapted it to various transmitters. I'm not intested in a transceiver. I want it to work with a boatanchor receiver like the .35 uv, 400 Hz, 1 kHz analog readout Heathkit SB-303 or the Collins 75S-1 with a CW mechanical filter and 1 kHz PTO. The trick is QSK, built in TR switch, and receiver muting. I'm not interested in a transceiver. I have several boatanchor receivers that work fine. KH6IJ (katashi) told me about 1960 that a 75S-1 with a CW mechanical filter was the "perfect" CW op's rig. At that time, he was a lowly paid University employee who ran a 75S-1 and an HT-32. I wondered why he didn't use a 32S-1 or KWM-2. I know the reason now. The 32S-1 and KWM-2 produce CW by injecting a sinewave audio tone into the SSB circuitry. Not the best method. CW from the HT-32 was better. The HT-32 also had the good Hallicrafter's VFO with great bandspread and smooth tuning. I know that I can buy a Century 21, HW-16, or Argonaut and have just as good a CW QSK experience but I want to use a separate receiver. Seems that at least one of the QRP CW transmitter kits would include QSK circuitry to TR and mute a receiver. de ah6gi/4 I have the receivers, I just need the transmitters. |
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On Wed, 15 Dec 2004 18:43:51 UTC, (Scott Dorsey)
wrote: No Spam No wrote: I want something like a tuna-tin or peanut whistle QRP transmitter but with QSK TR and receiver muting. I'm not saying that the tuna-tin won't work. I don't know if it will or not. The web articles are not explicit on that point. I'd like 1 to 5 watts of clean CW produced by a solid state transmitter. Something that runs on a wall wart would be best. Crystal controlled would be OK but I've been looking at WA6OTP's website. He sells a PTO kit. Some folk have adapted it to various transmitters. I'm not intested in a transceiver. I want it to work with a boatanchor receiver like the .35 uv, 400 Hz, 1 kHz analog readout Heathkit SB-303 or the Collins 75S-1 with a CW mechanical filter and 1 kHz PTO. Don't pass by the transceiver projects. Most of them don't really share anything between the transmitter and receiver sides, so there is no reason you can't just build the transmit section and leave the receive section. The trick is QSK, built in TR switch, and receiver muting. At these power levels, your QSK and TR switching can be done with a single relay. You are not talking kilowatts here. Your key connects to a multipole relay which disconnects the receiver and connects the transmitter to the antenna, keys the transmitter, and supplies a muting signal to the antenna. Any DP3T relay from the junkbox will work. Seems that at least one of the QRP CW transmitter kits would include QSK circuitry to TR and mute a receiver. There is no circuitry needed. It's just a relay for God's sake. --scott Well, I should explain a bit more. I've operated a Tentec Triton IV and own a Signal/One CX7A. The Trition IV is good, the CX7A is almost good enough. I'd like to have QSK not just automatic TR with a relay clacking away. I also have an ICOM IC-720A and it is too slow to be called QSK. Seems that at least one of fun things of CW is QSK. de ah6gi/4 I got a pointer to the 2004 handbook for an add on QSK system. -- |
On Wed, 15 Dec 2004 18:43:51 UTC, (Scott Dorsey)
wrote: No Spam No wrote: I want something like a tuna-tin or peanut whistle QRP transmitter but with QSK TR and receiver muting. I'm not saying that the tuna-tin won't work. I don't know if it will or not. The web articles are not explicit on that point. I'd like 1 to 5 watts of clean CW produced by a solid state transmitter. Something that runs on a wall wart would be best. Crystal controlled would be OK but I've been looking at WA6OTP's website. He sells a PTO kit. Some folk have adapted it to various transmitters. I'm not intested in a transceiver. I want it to work with a boatanchor receiver like the .35 uv, 400 Hz, 1 kHz analog readout Heathkit SB-303 or the Collins 75S-1 with a CW mechanical filter and 1 kHz PTO. Don't pass by the transceiver projects. Most of them don't really share anything between the transmitter and receiver sides, so there is no reason you can't just build the transmit section and leave the receive section. The trick is QSK, built in TR switch, and receiver muting. At these power levels, your QSK and TR switching can be done with a single relay. You are not talking kilowatts here. Your key connects to a multipole relay which disconnects the receiver and connects the transmitter to the antenna, keys the transmitter, and supplies a muting signal to the antenna. Any DP3T relay from the junkbox will work. Seems that at least one of the QRP CW transmitter kits would include QSK circuitry to TR and mute a receiver. There is no circuitry needed. It's just a relay for God's sake. --scott Well, I should explain a bit more. I've operated a Tentec Triton IV and own a Signal/One CX7A. The Trition IV is good, the CX7A is almost good enough. I'd like to have QSK not just automatic TR with a relay clacking away. I also have an ICOM IC-720A and it is too slow to be called QSK. Seems that at least one of fun things of CW is QSK. de ah6gi/4 I got a pointer to the 2004 handbook for an add on QSK system. -- |
You really don't need receiver muting for c.w. QSK,
just a receiver who's AGC can be turned off, or is very fast. I ran QSK with a crummy Lafayette HE-80 receiver, a B&W model 380 electronic TR switch, and a Heath Apache transmitter, all sharing a dipole. No keying relays used at all. If I zero-beated a station, I could just monitor my sending with my own receiver. For split frequencies, turn up the volume on the keying monitor. The point of the electronic TR switch is that it acts as a preamp for the receiver, until you transmit. Then, the tube in the TR switch is cut off due to its high value grid leak resistor, which protects the receiver's input stage. The signal is still loud, but if you switch the AGC off, you can hear a breaking station between dits. If your transmitter final is biased off during key up, you won't hear the white noise in the receiver. If your transmitter uses an AB1 or AB2 final for c.w., you may need to increase the final stage bias a bit in c.w. mode, to lower the quiescent plate current. If white noise is still present, you can use a separate antenna for the receiver/TR switch combination. Don't forget to use a coax low pass filter between the electronic TR switch and the antenna, or you will generate TV interference. 73, Ed Knobloch I know that I can buy a Century 21, HW-16, or Argonaut and have just as good a CW QSK experience but I want to use a separate receiver. Seems that at least one of the QRP CW transmitter kits would include QSK circuitry to TR and mute a receiver. de ah6gi/4 I have the receivers, I just need the transmitters. |
You really don't need receiver muting for c.w. QSK,
just a receiver who's AGC can be turned off, or is very fast. I ran QSK with a crummy Lafayette HE-80 receiver, a B&W model 380 electronic TR switch, and a Heath Apache transmitter, all sharing a dipole. No keying relays used at all. If I zero-beated a station, I could just monitor my sending with my own receiver. For split frequencies, turn up the volume on the keying monitor. The point of the electronic TR switch is that it acts as a preamp for the receiver, until you transmit. Then, the tube in the TR switch is cut off due to its high value grid leak resistor, which protects the receiver's input stage. The signal is still loud, but if you switch the AGC off, you can hear a breaking station between dits. If your transmitter final is biased off during key up, you won't hear the white noise in the receiver. If your transmitter uses an AB1 or AB2 final for c.w., you may need to increase the final stage bias a bit in c.w. mode, to lower the quiescent plate current. If white noise is still present, you can use a separate antenna for the receiver/TR switch combination. Don't forget to use a coax low pass filter between the electronic TR switch and the antenna, or you will generate TV interference. 73, Ed Knobloch I know that I can buy a Century 21, HW-16, or Argonaut and have just as good a CW QSK experience but I want to use a separate receiver. Seems that at least one of the QRP CW transmitter kits would include QSK circuitry to TR and mute a receiver. de ah6gi/4 I have the receivers, I just need the transmitters. |
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On Thu, 16 Dec 2004 06:27:16 UTC, Edward Knobloch
wrote: You really don't need receiver muting for c.w. QSK, just a receiver who's AGC can be turned off, or is very fast. ... the receiver's input stage. The signal is still loud, but if you switch the AGC off, you can hear a breaking station between dits. Thanks. I'd prefer to something more like Tentec's concept of QSK and not listen to a thumping receiver or hammer my S-meter against the pin. Done right, QSK is a delight. I think it can be done with off-the-shelf pieces. Looks like the key is the www.radioadv.com keyer-TR switch and just about any QRP transmitter kit, or at least that's what folk are telling me. de ah6gi/4 |
On Thu, 16 Dec 2004 08:29:16 UTC, TW wrote:
On 15 Dec 2004 14:19:25 GMT, "No Spam " No wrote: I've searched the web but haven't found the answer to my QRP CW question. I'm looking for a QRP CW transmitter kit that includes QSK and will mute a boatanchor receiver like an SB-303, SX-101, or 75S-1. I realize that some receivers might not recover fast enough for QSK. I've looked at website ads for Ramsey, Vectronixs, and still don't have an answer. They might do it out of the box; they might do it with a mod but I haven't found the answer. A couple watts of CW and capable of working with the WA6OTP PTO kit. Anyone got something like that working? de ah6gi/4 Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page 26: "Receiver Hook-up: You may patch most receivers directly into your VEC QRP-CW Transmitter's receiver jack without risk of damage. Transmitter output is typically around + 32 dBm and the energy reaching your receiver through the T/R switch is normally 25 dB lower, or about +7 dBm. This is a very strong signal, but a high-quality receiver with a wide AGC range can usually handle it without blasting out the speaker! If you are able to leave the receiver on during transmit, you'll enjoy the benefit of full QSK operation." "This means you'll be able to monitor incoming signals--and listen to your own outgoing signal--simultaneously. If your receiver has an attenuator switch, turning it on will help reduce the effects of overload. By the same token, if your receiver has a pre-amplifier, you should turn it off. Receivers unable to limit speaker or headphone volume over a wide range of signal inputs must be turned down or switched to standby mode while you send." Enough said? not enough but thanks for the terrific info. I've heard a Triton IV and Signal/One CX7A's concept of QSK and that's not exactly their concept. 40 years ago, I put a pot in series with the mute line on my SX-101A. That gave me an RF gain control that worked on receive and let me monitor my signal on SSB and CW. I didn't have break-in but I had the monitoring part. The QSK experience isn't just, "If I ignore the thumping of the receiver, clacking of relays, and the excessively loud transmit sidetone, I can maybe make out a dit between sent characters." QSK is the change-over happening so smoothly that it sounds like we're transmitting using code practice oscillators in the same room and I can control the volume and tone on both oscillators. Where you helped is this, I can combine that transmitter with the boatanchor TR-keyer described in the 2004 handbook and sold by www.radioadv.com to make a device that will mute my boatanchor receivers. Should work. Thanks. de ah6gi/4 -- |
On Thu, 16 Dec 2004 06:27:16 UTC, Edward Knobloch
wrote: You really don't need receiver muting for c.w. QSK, just a receiver who's AGC can be turned off, or is very fast. ... the receiver's input stage. The signal is still loud, but if you switch the AGC off, you can hear a breaking station between dits. Thanks. I'd prefer to something more like Tentec's concept of QSK and not listen to a thumping receiver or hammer my S-meter against the pin. Done right, QSK is a delight. I think it can be done with off-the-shelf pieces. Looks like the key is the www.radioadv.com keyer-TR switch and just about any QRP transmitter kit, or at least that's what folk are telling me. de ah6gi/4 |
On Thu, 16 Dec 2004 08:29:16 UTC, TW wrote:
On 15 Dec 2004 14:19:25 GMT, "No Spam " No wrote: I've searched the web but haven't found the answer to my QRP CW question. I'm looking for a QRP CW transmitter kit that includes QSK and will mute a boatanchor receiver like an SB-303, SX-101, or 75S-1. I realize that some receivers might not recover fast enough for QSK. I've looked at website ads for Ramsey, Vectronixs, and still don't have an answer. They might do it out of the box; they might do it with a mod but I haven't found the answer. A couple watts of CW and capable of working with the WA6OTP PTO kit. Anyone got something like that working? de ah6gi/4 Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page 26: "Receiver Hook-up: You may patch most receivers directly into your VEC QRP-CW Transmitter's receiver jack without risk of damage. Transmitter output is typically around + 32 dBm and the energy reaching your receiver through the T/R switch is normally 25 dB lower, or about +7 dBm. This is a very strong signal, but a high-quality receiver with a wide AGC range can usually handle it without blasting out the speaker! If you are able to leave the receiver on during transmit, you'll enjoy the benefit of full QSK operation." "This means you'll be able to monitor incoming signals--and listen to your own outgoing signal--simultaneously. If your receiver has an attenuator switch, turning it on will help reduce the effects of overload. By the same token, if your receiver has a pre-amplifier, you should turn it off. Receivers unable to limit speaker or headphone volume over a wide range of signal inputs must be turned down or switched to standby mode while you send." Enough said? not enough but thanks for the terrific info. I've heard a Triton IV and Signal/One CX7A's concept of QSK and that's not exactly their concept. 40 years ago, I put a pot in series with the mute line on my SX-101A. That gave me an RF gain control that worked on receive and let me monitor my signal on SSB and CW. I didn't have break-in but I had the monitoring part. The QSK experience isn't just, "If I ignore the thumping of the receiver, clacking of relays, and the excessively loud transmit sidetone, I can maybe make out a dit between sent characters." QSK is the change-over happening so smoothly that it sounds like we're transmitting using code practice oscillators in the same room and I can control the volume and tone on both oscillators. Where you helped is this, I can combine that transmitter with the boatanchor TR-keyer described in the 2004 handbook and sold by www.radioadv.com to make a device that will mute my boatanchor receivers. Should work. Thanks. de ah6gi/4 -- |
No Spam wrote: On Thu, 16 Dec 2004 06:27:16 UTC, Edward Knobloch wrote: You really don't need receiver muting for c.w. QSK, just a receiver who's AGC can be turned off, or is very fast. .. the receiver's input stage. The signal is still loud, but if you switch the AGC off, you can hear a breaking station between dits. Thanks. I'd prefer to something more like Tentec's concept of QSK and not listen to a thumping receiver or hammer my S-meter against the pin. Done right, QSK is a delight. I think it can be done with off-the-shelf pieces. Looks like the key is the www.radioadv.com keyer-TR switch and just about any QRP transmitter kit, or at least that's what folk are telling me. de ah6gi/4 I fully agree with you that, done right, QSK is a delight. I have been using a Heathkit HR-1680/HX-1681 combination for over 20 years now. The QSK works extremely well. It is virtually imperceptible that the receiver is actually being shut down during my dots and dashes. There is no thumping or bumping or hammering of the S-Meter, and I can hear all of the band activity. IMHO, I think that to have a good QSK setup, you must take the capabilities of both the receiver and transmitter into account. This Heathkit pair was designed to work together. There is a keying circuit inside that controls the timing of the receiver muting, transmitter keying, and T/R switch operation. No relays are involved at all. The low level keying and frequency generation is all solid state and the final (tubes) is run Class AB2, for a nice clean, well shaped, signal. It may be beneficial to get a copy of the HX-1681 transmitter and investigate how they implemented it. I haven't looked at the schematic in a long time but I don't think it was very complicated. It may be similar to Tentec's concept of QSK. I also seem to remember that in the ARRL Handbook, 2000 I think, there was a project for making implementing automatic T/R switching for vintage transmitters and receivers. I don't remember if they went into full QSK, or not, but it's another possible resource. -- Martin E. Meserve - K7MEM http://www.k7mem.com |
No Spam wrote: On Thu, 16 Dec 2004 06:27:16 UTC, Edward Knobloch wrote: You really don't need receiver muting for c.w. QSK, just a receiver who's AGC can be turned off, or is very fast. .. the receiver's input stage. The signal is still loud, but if you switch the AGC off, you can hear a breaking station between dits. Thanks. I'd prefer to something more like Tentec's concept of QSK and not listen to a thumping receiver or hammer my S-meter against the pin. Done right, QSK is a delight. I think it can be done with off-the-shelf pieces. Looks like the key is the www.radioadv.com keyer-TR switch and just about any QRP transmitter kit, or at least that's what folk are telling me. de ah6gi/4 I fully agree with you that, done right, QSK is a delight. I have been using a Heathkit HR-1680/HX-1681 combination for over 20 years now. The QSK works extremely well. It is virtually imperceptible that the receiver is actually being shut down during my dots and dashes. There is no thumping or bumping or hammering of the S-Meter, and I can hear all of the band activity. IMHO, I think that to have a good QSK setup, you must take the capabilities of both the receiver and transmitter into account. This Heathkit pair was designed to work together. There is a keying circuit inside that controls the timing of the receiver muting, transmitter keying, and T/R switch operation. No relays are involved at all. The low level keying and frequency generation is all solid state and the final (tubes) is run Class AB2, for a nice clean, well shaped, signal. It may be beneficial to get a copy of the HX-1681 transmitter and investigate how they implemented it. I haven't looked at the schematic in a long time but I don't think it was very complicated. It may be similar to Tentec's concept of QSK. I also seem to remember that in the ARRL Handbook, 2000 I think, there was a project for making implementing automatic T/R switching for vintage transmitters and receivers. I don't remember if they went into full QSK, or not, but it's another possible resource. -- Martin E. Meserve - K7MEM http://www.k7mem.com |
TW wrote:
Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page 26: "Receiver Hook-up: You may patch most receivers directly into your VEC QRP-CW Transmitter's receiver jack without risk of damage. Transmitter output is typically around + 32 dBm and the energy reaching your receiver through the T/R switch is normally 25 dB lower, or about +7 dBm. This is a very strong signal, but a high-quality receiver with a wide AGC range can usually handle it without blasting out the speaker! If you are able to leave the receiver on during transmit, you'll enjoy the benefit of full QSK operation." It would strike me that if you really wanted a full T/R switch, and you did not want to spend the five dollars or so for a fast relay, you could probably build an acceptable switch using 1N4007 diodes. I would think that with these current levels at HF that there would be no need for a fancy switching PIN diode. Another alternative, by the way, is just to use a vertical for transmitting and a horizontal dipole for receive. This also has some major benefits in that your receiver noise will be lower with the horizontal and your transmitted signal will be slightly better with the vertical. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
TW wrote:
Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page 26: "Receiver Hook-up: You may patch most receivers directly into your VEC QRP-CW Transmitter's receiver jack without risk of damage. Transmitter output is typically around + 32 dBm and the energy reaching your receiver through the T/R switch is normally 25 dB lower, or about +7 dBm. This is a very strong signal, but a high-quality receiver with a wide AGC range can usually handle it without blasting out the speaker! If you are able to leave the receiver on during transmit, you'll enjoy the benefit of full QSK operation." It would strike me that if you really wanted a full T/R switch, and you did not want to spend the five dollars or so for a fast relay, you could probably build an acceptable switch using 1N4007 diodes. I would think that with these current levels at HF that there would be no need for a fancy switching PIN diode. Another alternative, by the way, is just to use a vertical for transmitting and a horizontal dipole for receive. This also has some major benefits in that your receiver noise will be lower with the horizontal and your transmitted signal will be slightly better with the vertical. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
On 16 Dec 2004 12:33:55 GMT, "No Spam " No wrote:
On Thu, 16 Dec 2004 06:27:16 UTC, Edward Knobloch wrote: You really don't need receiver muting for c.w. QSK, just a receiver who's AGC can be turned off, or is very fast. .. the receiver's input stage. The signal is still loud, but if you switch the AGC off, you can hear a breaking station between dits. Thanks. I'd prefer to something more like Tentec's concept of QSK and not listen to a thumping receiver or hammer my S-meter against the pin. Done right, QSK is a delight. I think it can be done with off-the-shelf pieces. Looks like the key is the www.radioadv.com keyer-TR switch and just about any QRP transmitter kit, or at least that's what folk are telling me. de ah6gi/4 I'll admit it's not done very well in the stock Vectronics units. Using the 20m companion receiver, it's more like an AK47 in the headphones! Good thing they don't come with an S-meter! Hey, I paid $19 for a 30m model when TechAmerica had their closeout in Atlanta...minimal expectations. They are good for experimentation. I'm working on a solution for that QSK action, something better than the 1N914 they use. Good luck, Ted KX4OM |
On 16 Dec 2004 12:33:55 GMT, "No Spam " No wrote:
On Thu, 16 Dec 2004 06:27:16 UTC, Edward Knobloch wrote: You really don't need receiver muting for c.w. QSK, just a receiver who's AGC can be turned off, or is very fast. .. the receiver's input stage. The signal is still loud, but if you switch the AGC off, you can hear a breaking station between dits. Thanks. I'd prefer to something more like Tentec's concept of QSK and not listen to a thumping receiver or hammer my S-meter against the pin. Done right, QSK is a delight. I think it can be done with off-the-shelf pieces. Looks like the key is the www.radioadv.com keyer-TR switch and just about any QRP transmitter kit, or at least that's what folk are telling me. de ah6gi/4 I'll admit it's not done very well in the stock Vectronics units. Using the 20m companion receiver, it's more like an AK47 in the headphones! Good thing they don't come with an S-meter! Hey, I paid $19 for a 30m model when TechAmerica had their closeout in Atlanta...minimal expectations. They are good for experimentation. I'm working on a solution for that QSK action, something better than the 1N914 they use. Good luck, Ted KX4OM |
On 16 Dec 2004 12:33:55 GMT, "No Spam " No wrote:
On Thu, 16 Dec 2004 08:29:16 UTC, TW wrote: On 15 Dec 2004 14:19:25 GMT, "No Spam " No wrote: I've searched the web but haven't found the answer to my QRP CW question. I'm looking for a QRP CW transmitter kit that includes QSK and will mute a boatanchor receiver like an SB-303, SX-101, or 75S-1. I realize that some receivers might not recover fast enough for QSK. I've looked at website ads for Ramsey, Vectronixs, and still don't have an answer. They might do it out of the box; they might do it with a mod but I haven't found the answer. A couple watts of CW and capable of working with the WA6OTP PTO kit. Anyone got something like that working? de ah6gi/4 Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page 26: "Receiver Hook-up: You may patch most receivers directly into your VEC QRP-CW Transmitter's receiver jack without risk of damage. Transmitter output is typically around + 32 dBm and the energy reaching your receiver through the T/R switch is normally 25 dB lower, or about +7 dBm. This is a very strong signal, but a high-quality receiver with a wide AGC range can usually handle it without blasting out the speaker! If you are able to leave the receiver on during transmit, you'll enjoy the benefit of full QSK operation." "This means you'll be able to monitor incoming signals--and listen to your own outgoing signal--simultaneously. If your receiver has an attenuator switch, turning it on will help reduce the effects of overload. By the same token, if your receiver has a pre-amplifier, you should turn it off. Receivers unable to limit speaker or headphone volume over a wide range of signal inputs must be turned down or switched to standby mode while you send." Enough said? not enough but thanks for the terrific info. I've heard a Triton IV and Signal/One CX7A's concept of QSK and that's not exactly their concept. 40 years ago, I put a pot in series with the mute line on my SX-101A. That gave me an RF gain control that worked on receive and let me monitor my signal on SSB and CW. I didn't have break-in but I had the monitoring part. The QSK experience isn't just, "If I ignore the thumping of the receiver, clacking of relays, and the excessively loud transmit sidetone, I can maybe make out a dit between sent characters." QSK is the change-over happening so smoothly that it sounds like we're transmitting using code practice oscillators in the same room and I can control the volume and tone on both oscillators. Where you helped is this, I can combine that transmitter with the boatanchor TR-keyer described in the 2004 handbook and sold by www.radioadv.com to make a device that will mute my boatanchor receivers. Should work. Thanks. de ah6gi/4 I just posted a Boatanchor switching topic regarding a circuit in the 2003 Handbook based on sequenced switching for transverters. Is this the same article, or is there a separate TR article (I had borrowed the book from the library)? Ted KX4OM |
On 16 Dec 2004 12:33:55 GMT, "No Spam " No wrote:
On Thu, 16 Dec 2004 08:29:16 UTC, TW wrote: On 15 Dec 2004 14:19:25 GMT, "No Spam " No wrote: I've searched the web but haven't found the answer to my QRP CW question. I'm looking for a QRP CW transmitter kit that includes QSK and will mute a boatanchor receiver like an SB-303, SX-101, or 75S-1. I realize that some receivers might not recover fast enough for QSK. I've looked at website ads for Ramsey, Vectronixs, and still don't have an answer. They might do it out of the box; they might do it with a mod but I haven't found the answer. A couple watts of CW and capable of working with the WA6OTP PTO kit. Anyone got something like that working? de ah6gi/4 Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page 26: "Receiver Hook-up: You may patch most receivers directly into your VEC QRP-CW Transmitter's receiver jack without risk of damage. Transmitter output is typically around + 32 dBm and the energy reaching your receiver through the T/R switch is normally 25 dB lower, or about +7 dBm. This is a very strong signal, but a high-quality receiver with a wide AGC range can usually handle it without blasting out the speaker! If you are able to leave the receiver on during transmit, you'll enjoy the benefit of full QSK operation." "This means you'll be able to monitor incoming signals--and listen to your own outgoing signal--simultaneously. If your receiver has an attenuator switch, turning it on will help reduce the effects of overload. By the same token, if your receiver has a pre-amplifier, you should turn it off. Receivers unable to limit speaker or headphone volume over a wide range of signal inputs must be turned down or switched to standby mode while you send." Enough said? not enough but thanks for the terrific info. I've heard a Triton IV and Signal/One CX7A's concept of QSK and that's not exactly their concept. 40 years ago, I put a pot in series with the mute line on my SX-101A. That gave me an RF gain control that worked on receive and let me monitor my signal on SSB and CW. I didn't have break-in but I had the monitoring part. The QSK experience isn't just, "If I ignore the thumping of the receiver, clacking of relays, and the excessively loud transmit sidetone, I can maybe make out a dit between sent characters." QSK is the change-over happening so smoothly that it sounds like we're transmitting using code practice oscillators in the same room and I can control the volume and tone on both oscillators. Where you helped is this, I can combine that transmitter with the boatanchor TR-keyer described in the 2004 handbook and sold by www.radioadv.com to make a device that will mute my boatanchor receivers. Should work. Thanks. de ah6gi/4 I just posted a Boatanchor switching topic regarding a circuit in the 2003 Handbook based on sequenced switching for transverters. Is this the same article, or is there a separate TR article (I had borrowed the book from the library)? Ted KX4OM |
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TW wrote:
Hi Scott, The existing circuit simply uses one 1N4007 and a 1N4148 in series thru a .01 cap to the receiver muting input (it is not THAT simple, they are across the emitter and collector of the keying transistor; I tried to draw it in text symbols, but gave up). What I hear in the phones on keying is a loud "square wave" thump on each character sent. Try putting a capacitive shunt on the line that is providing the bias supply to the diodes, so they take a little bit of time to get up to voltage and back down. That may slow the action up a little bit, but it will also reduce the clicking. You may have to fiddle around with values (and you may need a combination of a ceramic and an electrolytic in parallel), but if the noise is caused by the rapid switching, it will fix it. If the noise is caused by DC offset on the output, a .1 uF ceramic in series with the receiver input will clean that up. This might be the case in receivers where there is a DC path through a coil winding from antenna to ground. I bought the Vectronics kits a couple of years ago after a period of inactivity due to illness, mainly to get engaged and productive on something. I'll check out some designs in my 2000 and earlier Handbooks for relay and/or diode switching better than the current Vectronics QSK design. I can in fact use a vertical and a dipole, so that is a good suggestion. Meanwhile, I enjoy QSK with my SW-20+. After working at a military installation where the procedure was to disconnect the UHF connector from the receiver and plug it into the transmitter between sending and receiving, I am just glad to have anything at all. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
TW wrote:
Hi Scott, The existing circuit simply uses one 1N4007 and a 1N4148 in series thru a .01 cap to the receiver muting input (it is not THAT simple, they are across the emitter and collector of the keying transistor; I tried to draw it in text symbols, but gave up). What I hear in the phones on keying is a loud "square wave" thump on each character sent. Try putting a capacitive shunt on the line that is providing the bias supply to the diodes, so they take a little bit of time to get up to voltage and back down. That may slow the action up a little bit, but it will also reduce the clicking. You may have to fiddle around with values (and you may need a combination of a ceramic and an electrolytic in parallel), but if the noise is caused by the rapid switching, it will fix it. If the noise is caused by DC offset on the output, a .1 uF ceramic in series with the receiver input will clean that up. This might be the case in receivers where there is a DC path through a coil winding from antenna to ground. I bought the Vectronics kits a couple of years ago after a period of inactivity due to illness, mainly to get engaged and productive on something. I'll check out some designs in my 2000 and earlier Handbooks for relay and/or diode switching better than the current Vectronics QSK design. I can in fact use a vertical and a dipole, so that is a good suggestion. Meanwhile, I enjoy QSK with my SW-20+. After working at a military installation where the procedure was to disconnect the UHF connector from the receiver and plug it into the transmitter between sending and receiving, I am just glad to have anything at all. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
On Thu, 16 Dec 2004 14:51:44 UTC, K7MEM wrote:
I fully agree with you that, done right, QSK is a delight. I have been using a Heathkit HR-1680/HX-1681 combination for over 20 years now. The QSK works extremely well. It is virtually imperceptible that the receiver is actually being shut down during my dots and dashes. There is no thumping or bumping or hammering of the S-Meter, and I can hear all of the band activity. IMHO, I think that to have a good QSK setup, you must take the capabilities of both the receiver and transmitter into account. This Heathkit pair was designed to work together. There is a keying circuit inside that controls the timing of the receiver muting, transmitter keying, and T/R switch operation. No relays are involved at all. The low level keying and frequency generation is all solid state and the final (tubes) is run Class AB2, for a nice clean, well shaped, signal. It may be beneficial to get a copy of the HX-1681 transmitter and investigate how they implemented it. I haven't looked at the schematic in a long time but I don't think it was very complicated. It may be similar to Tentec's concept of QSK. I also seem to remember that in the ARRL Handbook, 2000 I think, there was a project for making implementing automatic T/R switching for vintage transmitters and receivers. I don't remember if they went into full QSK, or not, but it's another possible resource. I'm hoping that www.radioadv.com version of the Handbook TR-Keyer will supply that level of control. I'm not in a rush to get this going. I'm mostly a listener and haven't been on HF for decades. I have a TH3jr and a 204BA (with 35 foot boom) both disassembled. I've been refurbing receivers. While I work on them, I'll listen to 40 CW or one of those 75 meter nets. I like to listen a couple times a month to keep my copying speed up. The more I hear about that handbook/radioadv TR-keyer, the more exciting it sounds. If it'll give me good QSK like a Triton IV or your HR-1680/HX-1681, it'll be well worth it. de ah6gi/4 qsy to 80 to listen for the QRP sprint. -- |
On Thu, 16 Dec 2004 14:51:44 UTC, K7MEM wrote:
I fully agree with you that, done right, QSK is a delight. I have been using a Heathkit HR-1680/HX-1681 combination for over 20 years now. The QSK works extremely well. It is virtually imperceptible that the receiver is actually being shut down during my dots and dashes. There is no thumping or bumping or hammering of the S-Meter, and I can hear all of the band activity. IMHO, I think that to have a good QSK setup, you must take the capabilities of both the receiver and transmitter into account. This Heathkit pair was designed to work together. There is a keying circuit inside that controls the timing of the receiver muting, transmitter keying, and T/R switch operation. No relays are involved at all. The low level keying and frequency generation is all solid state and the final (tubes) is run Class AB2, for a nice clean, well shaped, signal. It may be beneficial to get a copy of the HX-1681 transmitter and investigate how they implemented it. I haven't looked at the schematic in a long time but I don't think it was very complicated. It may be similar to Tentec's concept of QSK. I also seem to remember that in the ARRL Handbook, 2000 I think, there was a project for making implementing automatic T/R switching for vintage transmitters and receivers. I don't remember if they went into full QSK, or not, but it's another possible resource. I'm hoping that www.radioadv.com version of the Handbook TR-Keyer will supply that level of control. I'm not in a rush to get this going. I'm mostly a listener and haven't been on HF for decades. I have a TH3jr and a 204BA (with 35 foot boom) both disassembled. I've been refurbing receivers. While I work on them, I'll listen to 40 CW or one of those 75 meter nets. I like to listen a couple times a month to keep my copying speed up. The more I hear about that handbook/radioadv TR-keyer, the more exciting it sounds. If it'll give me good QSK like a Triton IV or your HR-1680/HX-1681, it'll be well worth it. de ah6gi/4 qsy to 80 to listen for the QRP sprint. -- |
Don't be satisfied with a simple arrangement that lets you get by. I worked CW
traffic nets at different level years ago with a thumping, banging system using headphones and now I wear two hearing aids and regret the nights that I called myself having a great time. Wish I could do it again and do it better! (broke=not working, retired=not working, retired=broke) |
Don't be satisfied with a simple arrangement that lets you get by. I worked CW
traffic nets at different level years ago with a thumping, banging system using headphones and now I wear two hearing aids and regret the nights that I called myself having a great time. Wish I could do it again and do it better! (broke=not working, retired=not working, retired=broke) |
On Fri, 17 Dec 2004 14:06:57 UTC, (Brokebob) wrote:
Don't be satisfied with a simple arrangement that lets you get by. I worked CW traffic nets at different level years ago with a thumping, banging system using headphones and now I wear two hearing aids and regret the nights that I called myself having a great time. Wish I could do it again and do it better! (broke=not working, retired=not working, retired=broke) I copy ya, man. That's a good reason for me to stay persistant and get the best, smoothest, real QSK system possible. This stuff about "two antennas" and let the AGC handle it, isn't right. I'd be trying to hear an S7 signal through my own S9+40 signal hammering away. I mentioned putting a pot in the mute line of my old SX-101A. That worked great. I was using a dowkey relay but that let me turn down the receiver gain on transmit. The only problem with that was I was using an HT-37 with the automatic changeover mod. It, and the dowkey relay were too slow for QSK. I know what I want. I've heard it on a Triton IV. Others have described their Heathkit twins with QSK done right. Signal/One is pretty good too. At 57 my hearing is not what it used to be. I'm not on hearing aids yet so I'm trying to keep every bit of that's left. I've been mulling over my speaker system. I use cheap hi-fi speakers with the tweeters disabled. I'm going for smooth, clean, rich sound. I'll give the www.radioadv.com bk175 kit a try. The write up on the site sounds like it does what I want. I hope it'll all fit in the case I have. de ah6gi/4 boatanchor qsk here I come. |
On Fri, 17 Dec 2004 14:06:57 UTC, (Brokebob) wrote:
Don't be satisfied with a simple arrangement that lets you get by. I worked CW traffic nets at different level years ago with a thumping, banging system using headphones and now I wear two hearing aids and regret the nights that I called myself having a great time. Wish I could do it again and do it better! (broke=not working, retired=not working, retired=broke) I copy ya, man. That's a good reason for me to stay persistant and get the best, smoothest, real QSK system possible. This stuff about "two antennas" and let the AGC handle it, isn't right. I'd be trying to hear an S7 signal through my own S9+40 signal hammering away. I mentioned putting a pot in the mute line of my old SX-101A. That worked great. I was using a dowkey relay but that let me turn down the receiver gain on transmit. The only problem with that was I was using an HT-37 with the automatic changeover mod. It, and the dowkey relay were too slow for QSK. I know what I want. I've heard it on a Triton IV. Others have described their Heathkit twins with QSK done right. Signal/One is pretty good too. At 57 my hearing is not what it used to be. I'm not on hearing aids yet so I'm trying to keep every bit of that's left. I've been mulling over my speaker system. I use cheap hi-fi speakers with the tweeters disabled. I'm going for smooth, clean, rich sound. I'll give the www.radioadv.com bk175 kit a try. The write up on the site sounds like it does what I want. I hope it'll all fit in the case I have. de ah6gi/4 boatanchor qsk here I come. |
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