Wiper is actually what I heard handy and them call it, I was mistaken on who I got the flapper term from. But like cable guy, it's sounds funny so I'm gonna stick with flapper, the word puts a giggle in me also when I say it, lol
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959 VFO windup question...
- Thread starter Hawkeye351
- Start date
In my 50 years, or better, of electronics it's always been "Wiper", a "Flapper" is what you find in an aquarium air pump, at no time does the wiper on a potentiometer "FLAP" by it's self.
I for one would give anyone who uses the word "Flapper" for a "Wiper" a big fat
.
Sorry, but I questioned in my mind why "Flapper" was being used in this thread and never heard it used in this way before.
Maybe if you want to "FLAP" your lips .......... be my guest.
(I just had to get that pun in.)
When I was in the Army, a "Lock-Washer" was not called a "Slit-Washer",
because a "Slit-Washer" is a ...... bar of soap and a towel.
Just my 2¢ .......... and a penny more for the pun.
73
I for one would give anyone who uses the word "Flapper" for a "Wiper" a big fat
.Sorry, but I questioned in my mind why "Flapper" was being used in this thread and never heard it used in this way before.
Maybe if you want to "FLAP" your lips .......... be my guest.
(I just had to get that pun in.)
When I was in the Army, a "Lock-Washer" was not called a "Slit-Washer",
because a "Slit-Washer" is a ...... bar of soap and a towel.
Just my 2¢ .......... and a penny more for the pun.
73
I figured id play with the mosfet idea before bed, this is where I'm at. Wurth 1000uF 16v, 2N7002 logic level mosfet, 24k gate to ground, 1.8k gate to red wire, drain to cap - , and the cap + to green. Source to brown.
With a couple resistors as a mock circuit around it, I get the impression that 1000uF is too much (with this mosfet anyhow). I was also not liking the fact it discharges at the same speed it charges. I twisted a couple diodes in there to simulate it charging through the pot wiper resistance and discharging right to the TX + rail (which gets drawn down fast on RX so basically ground to this thing). Windup slow, reset fast. Hopefully.
I will play with it more tomorrow after work. It might be possible to design this thing pretty well knowing the wiper voltage when aligned and the desired windup duration.
I'm going to bed and I probably won't sleep thinking of ways to add a couple JFETs to have the windup pot-adjustable.
With a couple resistors as a mock circuit around it, I get the impression that 1000uF is too much (with this mosfet anyhow). I was also not liking the fact it discharges at the same speed it charges. I twisted a couple diodes in there to simulate it charging through the pot wiper resistance and discharging right to the TX + rail (which gets drawn down fast on RX so basically ground to this thing). Windup slow, reset fast. Hopefully.
I will play with it more tomorrow after work. It might be possible to design this thing pretty well knowing the wiper voltage when aligned and the desired windup duration.
I'm going to bed and I probably won't sleep thinking of ways to add a couple JFETs to have the windup pot-adjustable.
What is the wiper voltage without the extra parts? I want to match that pot setting and watch the charge/discharge on the scope.
Played around a little more and made this circuit:
Here is the wiper voltage as the TX rail turns on and off when the wiper is set to 7v
and here is the wiper voltage with the wiper set to 5v
This suggests that with a 1000uF cap, the windup duration could last anywhere from 1 second to 3 seconds depending on where the wiper needs to be when aligned. This is why I am curious about the windup duration and your wiper voltage when aligned properly.
Those were with the mosfet gate tied to 8v constant. This is with the mosfet gate line tied to the TX rail
In the 5v case, it sped up a little. Not much happening in the 7v case. Nothing we can't change swapping caps, so doing this means we don't need a separate wire to the constant 8v regulator. Pretty sure the difference in time is due to the cap not discharging fully. When the TX rail goes below the voltage the mosfet needs to turn on, it disconnects the cap. The next time it turns on, there is residual voltage on the cap which decreases the charge time. This straight part is where it is already charged.
The part that bothers me is the exponential settle decay. It would be nice if the first 4.5 of the 5 RC time constants went like that and it then a hit a defined stop. Get the sound effect but not the long wait to be right on freq again. I'm thinking about isolating that entire circuit from the TX rail so the windup can be applied to the supply itself instead of the wiper so that a zener can clip the top of the decay off like this blue line before it even goes to VR7.
This is fun and I'm glad thats an SSB radio, but what I don't understand is why people install these in AM radios? Nobody gonna hear it unless it rides in on someone else's carrier.
Here is the wiper voltage as the TX rail turns on and off when the wiper is set to 7v
and here is the wiper voltage with the wiper set to 5v
This suggests that with a 1000uF cap, the windup duration could last anywhere from 1 second to 3 seconds depending on where the wiper needs to be when aligned. This is why I am curious about the windup duration and your wiper voltage when aligned properly.
Those were with the mosfet gate tied to 8v constant. This is with the mosfet gate line tied to the TX rail
In the 5v case, it sped up a little. Not much happening in the 7v case. Nothing we can't change swapping caps, so doing this means we don't need a separate wire to the constant 8v regulator. Pretty sure the difference in time is due to the cap not discharging fully. When the TX rail goes below the voltage the mosfet needs to turn on, it disconnects the cap. The next time it turns on, there is residual voltage on the cap which decreases the charge time. This straight part is where it is already charged.
The part that bothers me is the exponential settle decay. It would be nice if the first 4.5 of the 5 RC time constants went like that and it then a hit a defined stop. Get the sound effect but not the long wait to be right on freq again. I'm thinking about isolating that entire circuit from the TX rail so the windup can be applied to the supply itself instead of the wiper so that a zener can clip the top of the decay off like this blue line before it even goes to VR7.
This is fun and I'm glad thats an SSB radio, but what I don't understand is why people install these in AM radios? Nobody gonna hear it unless it rides in on someone else's carrier.
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I think that's the point, to sound like they drop in from a spaceship on an existing qso rather than just keying down and walking on someone. It's supposed to simulate an age when vfo's were the way to get on frequency. Check the super bowl sometimes, I hear them everyday keying on each other. Also, if you talk on a common channel, like 19, chances are very good at any time that there are already some carriers out there to pull this effect off, even if you don't hear them heterodyning together. I have only ever heard this on AM.
Wouldn't this also work on SSB?
Nevermind, I get it. Nobody uses it there because that last bit of the decay takes too long and would make you sound off freq. So if someone did to that windup on the trimmer supply with a zener to cap its exponential decay, I think it would work good on SSB too.
Well, if there were a pile up on ssb, think beehive, and you started talking as soon as you keyed, I think you would just sound either high to normal pitch, or something very unnatural, as there are no existing carriers for your key to mix with and you're not transmitting a carrier, or shouldn't be anyways.
doesnt take a carrier on SSB. Sweep a sig gen through your ssb receive. same sound without the carrier. As it passes through the crystal filter passband, you get the windup.
Well, I've never heard this effect on ssb, even if it does work. But is your sig gen creating a carrier for the ssb rx to hear while sweeping? Unless the ssb were unbalanced and outputting a carrier when you key, there is nothing going out the antenna jack until you modulate. Maybe all you need to do is detune carrier balance on ssb to achieve this effect?
I'm an idiot, you are right. I was thinking the receiving radio didn't need the carrier, but yea, there is nothing coming out of the SSB radio. At least as is.... What if a comparator determines when the windup is charging and momentarily unbalances the balanced modulator or something similar. IDK. I better take a break and think a while. Been up too long.
You're not an idiot, you're on another level and sometimes, the little details get lost while making room for more advanced thought. It happens, but you're thinking. Go get some rest.
If there's another AM carrier on the channel, they'll hear a BEEE-YOOP falling pitch heterodyne squeal as your carrier slides onto the channel.
Some folks are just easily amused. At least it's a cheap amusement.
73
Some folks are just easily amused. At least it's a cheap amusement.
73
Knew some guys in high school who had each bought identical Galaxy (Council Bluffs Iowa Galaxy) HF transceivers. They each mail-ordered a 1 rpm clock motor and rubber idler wheel meant for rim drive record turntables. The wheel fit onto the motor's shaft. With the clock motor's wheel leaning agains the radio's VFO knob, they carried on a QSO up the 40 meter band. When they stepped on a QSO in progress, they would apologize and state "we're just passing through, we'll be gone soon".
And yeah, they each got a 'pink ticket' QSL from the FCC. Warning only, didn't get fined.
Ah, youth.
73
And yeah, they each got a 'pink ticket' QSL from the FCC. Warning only, didn't get fined.
Ah, youth.
73