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curing chirp ??
The anonymous homebrew xmtr I picked up at the AWA meet last spring has finally make its first QSO, heard 589 in Texas by KE5HQ on 40 CW, but he reports what I sort of knew anyway...the rig has a chirp. The oscillator is an electron coupled 12BY7, crystal controlled. What are the cures for chirp ?? Slightly detune the buffer ?? add caps to the power supply. Trying the easiest things first, how should I proceed ?? |
curing chirp ??
William Mutch wrote:
The anonymous homebrew xmtr I picked up at the AWA meet last spring has finally make its first QSO, heard 589 in Texas by KE5HQ on 40 CW, but he reports what I sort of knew anyway...the rig has a chirp. The oscillator is an electron coupled 12BY7, crystal controlled. What are the cures for chirp ?? Slightly detune the buffer ?? add caps to the power supply. Trying the easiest things first, how should I proceed ?? The easiest first check is to try another crystal. -Bill |
curing chirp ??
Is it a chirp ( as in frequency change) or a click ( as in transients caused by keying )? Does the power supply sag at all under load? Regulating the screen on the 12BYZ may help considerbly. "William Mutch" wrote in message ell.edu... The anonymous homebrew xmtr I picked up at the AWA meet last spring has finally make its first QSO, heard 589 in Texas by KE5HQ on 40 CW, but he reports what I sort of knew anyway...the rig has a chirp. The oscillator is an electron coupled 12BY7, crystal controlled. What are the cures for chirp ?? Slightly detune the buffer ?? add caps to the power supply. Trying the easiest things first, how should I proceed ?? |
curing chirp ??
In message . edu,
William Mutch writes The anonymous homebrew xmtr I picked up at the AWA meet last spring has finally make its first QSO, heard 589 in Texas by KE5HQ on 40 CW, but he reports what I sort of knew anyway...the rig has a chirp. The oscillator is an electron coupled 12BY7, crystal controlled. What are the cures for chirp ?? Slightly detune the buffer ?? add caps to the power supply. Trying the easiest things first, how should I proceed ?? My DX100 had a bad chirp. Cured by cleaning the key contacts with fine emery paper. Mike G3IJE -- M.J.Powell |
curing chirp ??
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curing chirp ??
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curing chirp ??
Hate to tell you this, but with many classic few-tube transmitters you
get your choice: either chirp or clicking or chirp and click. If you key the oscillator, you get chirp. If you keep the oscillator running all the time and key the driver/final, then you get clicks. Not to mention some backwave (leakage of carrier when you are key-up, leakage is almost inevitable in a tube oscillator where you running the oscillator at 10 or 20V P-P.) Without enough buffering you also get chirps as the keying of the later stages loads down the oscillator stage. A 50's or 60's ARRL Handbook will have a chapter about the tradeoffs in keying methods. Many 4 or 5-tube transmitters, despite all their buffering and keying stages and VR tube, still have noticable chirp/click and while you should certainly strive to understand the issue, you will have some chirp with any simplistic TX. In terms of not interfering with QSO's up and down the band, some chirp is preferable to some click. Tim. |
curing chirp ??
The power amplifier, when keyed, causes the main HT supply volts to
change at a rate which depends on the size of the HT smoothing capacitors. This change in HT volts also affects the DC supply to the oscillator tube which causes the frequency to change in sympathy with volts. Most tube oscillators change frequency with supply volts. So stabilise the DC supply voltages to the xtl oscillator - especially the screen-grid DC volts. It won't matter if the DC supply volts are increased by 15 or 20 percent in the process. Use a gas-filled voltage stabiliser tube if you can find and fit one. They used to be available in voltages from 50, 75, 90 to 150 volts. But a few transistors could do the job. Adding caps to the power supply will merely slow down the chirp and perhaps make it more noticeable. If the DC supply to the oscillator is already stabilised then there may be a small amount of RF feedback from buffer or power amplifier to the oscillator. In which case you have a much more complicated problem to solve. ---- Reg, G4FGQ |
curing chirp ??
One more thing. If the crystal is driven heavily, it heats up and chirps.
Reducing the amount of feedback in the oscillator can help, but can be tricky as well. No suggestions where to proceed without knowing the circuit. 73, Steve K9DCI "Bill" wrote in message ... William Mutch wrote: The anonymous homebrew xmtr I picked up at the AWA meet last spring has finally make its first QSO, heard 589 in Texas by KE5HQ on 40 CW, but he reports what I sort of knew anyway...the rig has a chirp. The oscillator is an electron coupled 12BY7, crystal controlled. What are the cures for chirp ?? Slightly detune the buffer ?? add caps to the power supply. Trying the easiest things first, how should I proceed ?? The easiest first check is to try another crystal. -Bill |
curing chirp ??
William Mutch wrote:
The anonymous homebrew xmtr I picked up at the AWA meet last spring has finally make its first QSO, heard 589 in Texas by KE5HQ on 40 CW, but he reports what I sort of knew anyway...the rig has a chirp. The oscillator is an electron coupled 12BY7, crystal controlled. What are the cures for chirp ?? Slightly detune the buffer ?? add caps to the power supply. Trying the easiest things first, how should I proceed ?? I always liked the sound of a chirpy signal. It never bothered me, and when you hear one now you know there's a real ham behind the key! Irv VE6BP -- -------------------------------------- Diagnosed Type II Diabetes March 5 2001 Beating it with diet and exercise! 297/215/210 (to be revised lower) 58"/43"(!)/44" (already lower too!) -------------------------------------- Visit my HomePage at http://members.shaw.ca/finkirv/index.html Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm -------------------- Irv Finkleman, Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP Calgary, Alberta, Canada |
curing chirp ??
M. J. Powell wrote:
In message . edu, William Mutch writes The anonymous homebrew xmtr I picked up at the AWA meet last spring has finally make its first QSO, heard 589 in Texas by KE5HQ on 40 CW, but he reports what I sort of knew anyway...the rig has a chirp. The oscillator is an electron coupled 12BY7, crystal controlled. What are the cures for chirp ?? Slightly detune the buffer ?? add caps to the power supply. Trying the easiest things first, how should I proceed ?? My DX100 had a bad chirp. Cured by cleaning the key contacts with fine emery paper. If it ever comes to that again, don't use emery, or any abrasive paper, to clean up electrical contacts. The abrasive tends to embed into the soft contact material, and make for contact problems. The recommended repair is to burnish the contacts. That can be done by taking an old hacksaw blade, and grinding the flat sides on a coarse grinding wheel. The grinding wheel will put fine scratches in the saw blade's sides, and these scratches make a pretty nice, very fine file... perfect for burnishing key and relay contacts. 'Chuck |
curing chirp ??
In the old days, chirp was a favorite discussion topic.
You have been given a number of ideas, so here are a few more. When the feedback capacitor dielectric heats up, the frequency can change. Using an air dielectric is best, but a silver mica or NP0 capacitors usually work. If you do not want to regulate the screen voltage on the oscillator, you can adjust it until you find the "sweet" spot, which will reduce drift. You need a tapped resistor or rheostat to do that. Crystal oscillators are supposed to be simple, so the cure should be simple, too. Something is heating up causing a frequency change when you key it. Make sure you are not overloading your receiver, causing a phantom chirp (only one can hear it is you). 73, Colin K7FM |
curing chirp ?? (why).
"Irv Finkleman" wrote in message ... William Mutch wrote: The anonymous homebrew xmtr I picked up at the AWA meet last spring has finally make its first QSO, heard 589 in Texas by KE5HQ on 40 CW, but he reports what I sort of knew anyway...the rig has a chirp. The oscillator is an electron coupled 12BY7, crystal controlled. What are the cures for chirp ?? Slightly detune the buffer ?? add caps to the power supply. Trying the easiest things first, how should I proceed ?? I always liked the sound of a chirpy signal. It never bothered me, and when you hear one now you know there's a real ham behind the key! Irv VE6BP Chirps, clicks and fists were the identification marks of the operator. I, for one, always admired the variance of sounds from one rig to another. For example, at one time in history, the DX-100 was unmistakable, and if the operator was using a straight key, one could call him by name immediately. If your report was a "c" (534C) for example, you knew that you had more than a "c" (chirp), but probably a "yoop", and were probably using a rehashed command set or a liaison rig...... BC-459, BC-191 or BC-375 maybe. BC-375 using a 28 volt dynamotor on 24 volts of fading automobile batteries required two hands at the receiving end, and heaven help him if he needed a pencil as well to copy! Lynn, W7LTQ..... long live the chirp! |
Hello gang
Little chirp never hurt anybody, some chirp ads character to a signal not about to change 60 year old ART-13 or play around other old style tube/hb transmitters to try to get rid of something, I like! key clicks diffrent story nothing like causing crud 10 kc or more up and down band when I hear a chirp on some ops sig usualy it means they are running hb or older tube rig often give them a call know if start to talk about 6AG7 6L6 mopa, 45 push pull hartley or autodine receivers there is a good chance the op on the other end will know what the heck im talking about and not come back with "wx here is" still use an old bug, so not only have a chirp, but also some Lake Eire swing please keep those OO cards comming in for drift and chirp working on WAS OO thank you Mac w8znx, real radios still glow in the dark |
curing chirp ??
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curing chirp ??
Chirp is for the birds.
Pfoooot! Chirp Chirp Chirp Chirp, Chirp Chirp Lynn, W7LTQ (1948 with BC-375) |
curing chirp ??
Lynn Coffelt wrote:
Chirp is for the birds. Pfoooot! Chirp Chirp Chirp Chirp, Chirp Chirp Lynn, W7LTQ (1948 with BC-375) Like the signal I heard last night around 7070 Kc: light chirp, and a constant slow drift across the band. Lovely 1950s signal, and the op (N5BBB, I think) had a lovely fist to go with it. I could listen to it all night -- if I could catch up with it. ;=) -- Mike Andrews W5EGO 15WPM on a really good day Extra Tired old sysadmin working on his code speed |
curing chirp ??
Sez you...
"Don Bowey" wrote in message ... On 12/8/05 2:09 PM, in article , "de Mac" wrote: Hello gang Little chirp never hurt anybody, some chirp ads character to a signal not about to change 60 year old ART-13 or play around other old style tube/hb transmitters to try to get rid of something, I like! key clicks diffrent story nothing like causing crud 10 kc or more up and down band when I hear a chirp on some ops sig usualy it means they are running hb or older tube rig often give them a call know if start to talk about 6AG7 6L6 mopa, 45 push pull hartley or autodine receivers there is a good chance the op on the other end will know what the heck im talking about and not come back with "wx here is" still use an old bug, so not only have a chirp, but also some Lake Eire swing please keep those OO cards comming in for drift and chirp working on WAS OO thank you Mac w8znx, real radios still glow in the dark In the 50's, just as today, chirp was something only a Lid's transmitter would have. It was *rare* that anyone had a persistent chirp. If someone had chirp they fixed it; sometimes with a hammer. Even some crystal chirp faults could be fixed by a little work on the bevel of the crystal's edge. Chirp is for the birds. Swing is for those who have it, not make it. Yes, real radios glow in the dark, but today's fake radios have better specs and DO perform better. My old line through 60 years included BC-312, a couple HROs, HQ-129X, NC-125, SX-100, GPR-90, 51J-4, some homebrew, and some I don't recall, but I like my R71A better than all of them. Nostalgia looks great on a shelf. A 300W plate modulated signal using an old D-104 mike on 75M still sounds great. Don |
Yes, real radios glow in the dark, but today's fake radios have better[/color]
specs and DO perform better. My old line through 60 years included BC-312, a couple HROs, HQ-129X, NC-125, SX-100, GPR-90, 51J-4, some homebrew, and some I don't recall, but I like my R71A better than all of them. Nostalgia looks great on a shelf. A 300W plate modulated signal using an old D-104 mike on 75M still sounds great. Don [/quote] most of the better old tube receivers can still copy weak sig on 80 or 40 cw than most of the so called modern dc to daylight solid state radios you can keep the R71A I will keep using my 75S 3, 2A, 2B, NC 183D, HRO 5RA 1, R 390A and if nostalgia realy looks best on the shelf guess 300watts class b plate mod am rig should also be set aside for modern JA rice box radios lets see now you object to lake eire swing and chirp but like class b plate mod AM on 75 meters sure sounds like the pot calling the kettle black to me de Mac w8znx |
curing chirp ??
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curing chirp ??
I wouldn't be surprised to see MFJ or one of the other manufacturers
to come out with a 'Chirp Inserter -- to make you sound like a real ham' Irv VE6BP -- -------------------------------------- Diagnosed Type II Diabetes March 5 2001 Beating it with diet and exercise! 297/215/210 (to be revised lower) 58"/43"(!)/44" (already lower too!) -------------------------------------- Visit my HomePage at http://members.shaw.ca/finkirv/index.html Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm -------------------- Irv Finkleman, Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP Calgary, Alberta, Canada |
curing chirp ??
I wouldn't be surprised to see MFJ or one of the other manufacturers to come out with a 'Chirp Inserter -- to make you sound like a real ham' Irv VE6BP 1965 ...... after several weeks of collecting junk parts ...... it was ready .....my transmitter ... didn't have a 6L6 but did have a 6F6 if I remember ..... hook her up to a sloping 40 meter dipole .....2 weeks later and after hundreds of CQs ....an answer from another novice about 5 miles away who stated my signal was very poor and raspy ....then to my amazement the next day .....a postcard from an OO (official observer ARRL) in Oregon. ..... with the same information ....I still have that card somewhere as proof that the old Pop Electronics rig did get out ...... Yep the magic was there. God bless and Merry Christmas all ... Tom Popovic KI3R Belle Vernon PA |
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