Versapulse Transmitter Build Log
07-16-2013, 09:51 AM
#26
RE: Versapulse Transmitter Build Log
ORIGINAL: ukengineman
I ran your antenna dimensions through the links I put on your centre loaded antenna thread. For 27MHz inductance came out at 4.6uH and with your 0.5 inch former turns came out at 39. It might be advisable to start with say 40T as it is easier to remove turns rather than adding them when tuning with a field strength meter.
Alan
ORIGINAL: crigotti
I worked on the antenna some tonight. It'll be 54 inches long and have a center loaded coil. Thanks for the info on antennas and I'm thinking about 30 to 32 turns might be a good starting place. BTW, I'll be using 24awg magnet wire for the coil.
I worked on the antenna some tonight. It'll be 54 inches long and have a center loaded coil. Thanks for the info on antennas and I'm thinking about 30 to 32 turns might be a good starting place. BTW, I'll be using 24awg magnet wire for the coil.
Alan
07-16-2013, 06:25 PM
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RE: Versapulse Transmitter Build Log
Alan,
Thanks for working out the turns. 39 does seem high though. I'll go with 40 to start with and then unwind to tune.
Dan,
That's a good idea to short the windings to tune. At least to get it close.
Thanks for working out the turns. 39 does seem high though. I'll go with 40 to start with and then unwind to tune.
Dan,
That's a good idea to short the windings to tune. At least to get it close.
07-16-2013, 06:59 PM
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RE: Versapulse Transmitter Build Log
Here is my step-by-step on using Press-N-Peel to create an etched pcb.
1) I print out my artwork on my Brother laser printer. It is a HL-5370DW. I've read where it takes a lot of heat when using a Brother laser printer. It seems to work OK. The settings are 1200dpi with density adjustment as -6.
2) To prepare the pcb, I take and sand the edges smooth. This knocks off the "ridge" from shearing the pcb to size before you get it. All mine are 4 x 6 inches.
3) I then plug in my Top Flite Monokote sealing iron. Turn it up all the way and remove the sock if so fitted.
4) I clean the copper using Lime-Away and a Scotch-Brite pad under running water. I spray the Lime-Away on the board and swish it around then use the Scotch-Brite pad to shine up the copper. Do not touch the copper with you hands from now on.
5) I then dry off the board with a paper towel. Probably a better choice would be a lint free cloth.
6) I then clean off the board again with some 90% rubbing alcohol.
7) I place the pcb on a smooth block of wood with a paper towel on top of the wood. I do this to cancel any bumps etc that the wood might have. I'm trying to got the pcb to rest on a flat surface as possible.
8) I then place the Press-N-Peel on top of the board.
9) Then on top of that I use a clean piece of copy paper.
10) Then I apply the sealing iron to the paper. Gently at first to "stick" the Press-N-Peel in place. Then after a minute or so of going over the entire surface, I start to use a lot of pressure. Usually 2 hands and rub over the entire surface going in back and forth motions. I never go circular. I do this for several minutes, 4 or 5. Make sure you get everywhere along the edges too.
11) It's time to "quench" the Press-N-Peel off the pcb board. I grab the board using a couple of paper towels. It's HOT! I then place the pcb under cold running water in the sink. In less than a minute you can peel off the Press-N-Peel and you'll be left with your artwork on the pcb.
12) Dab gently with a paper towel to dry.
13) Inspect the artwork. If it needs touched up, I use a fine line Sharpie.
I find doing a smaller board rather than the 4 x 6 board a lot easier. The traces are more consistent. I do find that where the rollers from the Brother laser printer go along the Press-N-Peel, I have problems with getting a nice solid trace and requires more touch-up.
The switcher boards that I made from the 4 x 6 pcb board had a fair number of bad traces from the rollers and will have to be scrapped. But I think out of the 30 sets, 20-24 will be useable. I think if I did this again, I'll do a 4 x6 board in 3 pieces of 2 x 4.
I do use the hydrogen peroxide and muriatic acid method to actually do the etching.
This is a time where captions could be used with pictures. I suppose I could put each step with a picture in each post.
1) I print out my artwork on my Brother laser printer. It is a HL-5370DW. I've read where it takes a lot of heat when using a Brother laser printer. It seems to work OK. The settings are 1200dpi with density adjustment as -6.
2) To prepare the pcb, I take and sand the edges smooth. This knocks off the "ridge" from shearing the pcb to size before you get it. All mine are 4 x 6 inches.
3) I then plug in my Top Flite Monokote sealing iron. Turn it up all the way and remove the sock if so fitted.
4) I clean the copper using Lime-Away and a Scotch-Brite pad under running water. I spray the Lime-Away on the board and swish it around then use the Scotch-Brite pad to shine up the copper. Do not touch the copper with you hands from now on.
5) I then dry off the board with a paper towel. Probably a better choice would be a lint free cloth.
6) I then clean off the board again with some 90% rubbing alcohol.
7) I place the pcb on a smooth block of wood with a paper towel on top of the wood. I do this to cancel any bumps etc that the wood might have. I'm trying to got the pcb to rest on a flat surface as possible.
8) I then place the Press-N-Peel on top of the board.
9) Then on top of that I use a clean piece of copy paper.
10) Then I apply the sealing iron to the paper. Gently at first to "stick" the Press-N-Peel in place. Then after a minute or so of going over the entire surface, I start to use a lot of pressure. Usually 2 hands and rub over the entire surface going in back and forth motions. I never go circular. I do this for several minutes, 4 or 5. Make sure you get everywhere along the edges too.
11) It's time to "quench" the Press-N-Peel off the pcb board. I grab the board using a couple of paper towels. It's HOT! I then place the pcb under cold running water in the sink. In less than a minute you can peel off the Press-N-Peel and you'll be left with your artwork on the pcb.
12) Dab gently with a paper towel to dry.
13) Inspect the artwork. If it needs touched up, I use a fine line Sharpie.
I find doing a smaller board rather than the 4 x 6 board a lot easier. The traces are more consistent. I do find that where the rollers from the Brother laser printer go along the Press-N-Peel, I have problems with getting a nice solid trace and requires more touch-up.
The switcher boards that I made from the 4 x 6 pcb board had a fair number of bad traces from the rollers and will have to be scrapped. But I think out of the 30 sets, 20-24 will be useable. I think if I did this again, I'll do a 4 x6 board in 3 pieces of 2 x 4.
I do use the hydrogen peroxide and muriatic acid method to actually do the etching.
This is a time where captions could be used with pictures. I suppose I could put each step with a picture in each post.
Last edited by crigotti; 08-17-2013 at 05:25 PM.
08-17-2013, 05:25 PM
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Time for an update. The case took way too long to get made. But it finally got made and the wait was worth it. It turned out perfect! I covered the aluminum case with some automobile "wrap" I found on eBay. The guy was selling a piece 15 inches wide by 24 inches long. Just what I needed. $5 delivered! It worked great. The orange will compliment the Jr. Sky Squire color scheme of orange with black and white trim.
I redid the stick assembly by using pots with 6mm shafts and a new way to capture the shaft to the gimble. Worked very well. I also added some stops for the sticks so I can adjust them to keep the actuator from cycling when moving the stick all the way. I had to short out the 2.2K (item 26 in the schematic) so I could get some adjustment of the tone pot. I remade the RF coil with the windings all the way down on the form so the slug would have some effect on tuning. Everything else is per the article.
I used a LM7809 positive fixed voltage regulator powered by a 3 cell Lipo battery.
The antenna has 20 turns of 24awg magnet wire. 17 inches from the bottom to the bottom of the coil and 25 1/2 inches from the top of the coil to the tip of the antenna. I think the antenna tip can be shortened about 1 inch yet. I'm using JMP method of tuning the antenna by watching the FS meter as I grab the transmitter. Worked very well.
I have to get the transmitter tuned by somebody with a FCC license and then tune the receiver. I have the LR-3 working very well now.
Enjoy the pics.
I redid the stick assembly by using pots with 6mm shafts and a new way to capture the shaft to the gimble. Worked very well. I also added some stops for the sticks so I can adjust them to keep the actuator from cycling when moving the stick all the way. I had to short out the 2.2K (item 26 in the schematic) so I could get some adjustment of the tone pot. I remade the RF coil with the windings all the way down on the form so the slug would have some effect on tuning. Everything else is per the article.
I used a LM7809 positive fixed voltage regulator powered by a 3 cell Lipo battery.
The antenna has 20 turns of 24awg magnet wire. 17 inches from the bottom to the bottom of the coil and 25 1/2 inches from the top of the coil to the tip of the antenna. I think the antenna tip can be shortened about 1 inch yet. I'm using JMP method of tuning the antenna by watching the FS meter as I grab the transmitter. Worked very well.
I have to get the transmitter tuned by somebody with a FCC license and then tune the receiver. I have the LR-3 working very well now.
Enjoy the pics.
08-18-2013, 02:21 AM
#32
FCC license
I passed the second class in 1969 and he reduced it to a General Radiotelephone Operators License in 1983. Both First and Second class are now GROL. I only need it to work on aircraft radios which is the reason I got it in the first place, which I no longer do.
08-18-2013, 06:44 AM
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FCC license is no longer required to tune xmitter especially a home built on 27 MHz. This was changed in 1983 under Reagan's paper work reduction act.
I passed the second class in 1969 and he reduced it to a General Radiotelephone Operators License in 1983. Both First and Second class are now GROL. I only need it to work on aircraft radios which is the reason I got it in the first place, which I no longer do.
I passed the second class in 1969 and he reduced it to a General Radiotelephone Operators License in 1983. Both First and Second class are now GROL. I only need it to work on aircraft radios which is the reason I got it in the first place, which I no longer do.
11-03-2013, 06:34 PM
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Harvey,
I haven't done much with it for awhile. Matter-of-fact I'm sending it to Jay Mendoza for a final look over and tune up this week. I didn't want to send it to him sooner because I wanted to show it to some club members in October. Now that I'm finished with other obligations, I'm sending it off early this week.
Thanks for asking.
I haven't done much with it for awhile. Matter-of-fact I'm sending it to Jay Mendoza for a final look over and tune up this week. I didn't want to send it to him sooner because I wanted to show it to some club members in October. Now that I'm finished with other obligations, I'm sending it off early this week.
Thanks for asking.
02-20-2014, 05:23 PM
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Yeah, an update is long overdue. I sent the system to Jay Mendoza. He tuned it and has it working very well. He added some RF chokes inline with the wires going to the RF board. I think that I have too much wires inside the transmitter case. I'll shorten them and do a long range check on the system when the weather gets a lot better in a month or 2. Very happy with it.
I did notice that the elevator stick doesn't change the pulse rate quite enough. In other words the rate only changes from 2cps to like 10cps not 2cps to 12cps. I'll order a 250K pot and use that instead of the 100K pot that I have in there now. I use a 250K resistor across the resistance to give me a 125K pot which should give me "full throw" on the elevator.
Again, I'll let you know how that turns out.
I did notice that the elevator stick doesn't change the pulse rate quite enough. In other words the rate only changes from 2cps to like 10cps not 2cps to 12cps. I'll order a 250K pot and use that instead of the 100K pot that I have in there now. I use a 250K resistor across the resistance to give me a 125K pot which should give me "full throw" on the elevator.
Again, I'll let you know how that turns out.
02-20-2014, 05:55 PM
#39
I did notice that the elevator stick doesn't change the pulse rate quite enough. In other words the rate only changes from 2cps to like 10cps not 2cps to 12cps. I'll order a 250K pot and use that instead of the 100K pot that I have in there now. I use a 250K resistor across the resistance to give me a 125K pot which should give me "full throw" on the elevator.
Again, I'll let you know how that turns out.
Again, I'll let you know how that turns out.
02-24-2014, 10:46 AM
#42
Try reducing the resistor #6 from 6.8K to 5.6K , or 4.7K and see what happens. If you get rid of the LiPo, it will eliminate those extra charge plug wires which I think are acting like antennas and causing some of the RF problems I had to cure with chokes.
Jay
Jay
Last edited by jaymen; 02-24-2014 at 10:48 AM.
12-29-2014, 01:48 PM
#44
Update to post:
I received the Versa Pulse Tx from Christ, what a beauty, and very top notch workmanship. The center load needed more turns, so I re-wound it and got the output to tune up perfectly. The LiPo battery had a 4 pin charge plug with a negative ground pin, which needed to be wired to the case ground to stabilize the system. Normally, with NiCads, this is not necessary but LiPos, being higher impeadance, act differently. Christ has now done several revisions for me to the JBR tone, pulse, and Galloping Ghost receivers so we will now have 5 models to choose from. He also laid out a newer and smaller version of the Rand switcher for the Rand GG-Pak, and also made a board for the rand Dual Pak decoder. I have amassed the parts and am now able to build these to order for those who want one.
We have a couple future projects: a GG motor control for ESC as used in electric powered planes that takes uses the throttle ouput from the LR-3 to give you a signal for your speed control. We also are going to be making up an interface board that simplifies converting old digital proportional sets to 2.4GHz.
I received the Versa Pulse Tx from Christ, what a beauty, and very top notch workmanship. The center load needed more turns, so I re-wound it and got the output to tune up perfectly. The LiPo battery had a 4 pin charge plug with a negative ground pin, which needed to be wired to the case ground to stabilize the system. Normally, with NiCads, this is not necessary but LiPos, being higher impeadance, act differently. Christ has now done several revisions for me to the JBR tone, pulse, and Galloping Ghost receivers so we will now have 5 models to choose from. He also laid out a newer and smaller version of the Rand switcher for the Rand GG-Pak, and also made a board for the rand Dual Pak decoder. I have amassed the parts and am now able to build these to order for those who want one.
We have a couple future projects: a GG motor control for ESC as used in electric powered planes that takes uses the throttle ouput from the LR-3 to give you a signal for your speed control. We also are going to be making up an interface board that simplifies converting old digital proportional sets to 2.4GHz.
01-09-2015, 06:22 PM
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I'm curious as to what kinds of GG packages you're planning to offer. I know that this isn't the forum for sales pitches so I won't ask for prices. However, I AM intrigued with your work in this long forgotten segment of 1960s R/C evolution. I remember drooling over the ads for GG systems in the mid & late 1960s RCM mags but couldn't afford one at the time. By the time I could, digital propo had taken over.
Harvey
Harvey
