Topics

Tuning knob

Gigabyte
 

I just assembled my V5 with Nextion 3.5E screen in a case and the tuning encoder knob doesn't seem to work.  I've checked and double checked everything. Does anybody have any suggestions on what to do to troubleshoot it.  I can click the wheel.  Turning it every once in a while will move the frequency display a little bit, but most of the time it does nothing.   

Evan Hand
 

Two possibilities come up in to me:

1 - Test the encoder using a scope while the unit is on.  That would be connect a probe to each of the two encoder (not switch) pins and rotate at a constant speed to verify that the pulse is there (note, it will be a zero pulse, in that the encoder is switching to ground). If you have a dual trace scope you can verify that the pulses are 90 degrees out of phase. Otherwise test each individually to verify operation.

2 - replace the Nano if you have a spare.

I have read of similar issues with others.  In at least one case the solution was to install pull up resistors as is used for the CW key input.

If it were my rig, and since I have spare Nanos, I would go that route first.  Some Nanos are better at sensing the encoder than others.

Just suggestions.  There could be more at play here.

73
Evan
AC9TU

Dean Souleles
 

I'd start with simple things first. It might be a poor ground connection. I had to scrape the paint off the inside of my case around all the controls to ensure a good ground. Once I did that the encoder started working consistently.

73,
Dean
KK4DAS

Gigabyte
 

Evan, 

I only have a little MiniDSO 4 channel. It's this one here: https://amzn.to/32m1Qkr 
Not an electronics guru. I don't use my little scoped that often so I'm not great with it, but I checked it with the DSO. I was getting very bouncy readings on one side of it. It was very random. The other I was getting a regular dip to zero as I turned the dial. So I'm guessing the encoder is bad. 

Encoders look like they're cheap so I was thinking of ordering this pair of them from eBay: https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575553925&campid=5338625465&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F2X-EC-11-Rotary-Encoder-Digital-Potentiometer-20mm-Knurled-Shaft-with-Switch-USA%2F382783349631%3Fhash%3Ditem591faa637f%3Ag%3AzG4AAOSweEFcYvuH
Will that one I linked work? If so I'll go ahead and order as soon as I hear back from you if that's the correct kind to get. One of the pictures in the auction listing shows a diagram with resistors in it. I'm assuming this is what you were talking about there. 

I have several other Nanos, but they already have have headers soldered on the wrong side of the board. I'll have to get some more without the headers soldered on and solder headers on them. I'm really not the greatest at desoldering things, especially long rows of headers. 

Dean, 

My case isn't grounded right now. It's actually 6 seperate pieces of metal, so it will take me some work to get it all grounded well. This is the case I have: https://amzn.to/2HQEavb
 
The black part in my pictures (white if you look at the Amazon listing) is actually plastic. The front metal panel sits in the plastic. Same for the rear panel. The two plastic pieces on the ends are bolts to the bottom metal pan, and there are two metal rails at the top on each side. Then the metal cover that goes over the top and sides. It was blue and white like in the pictures on Amazon. I painted the plastic black and the metal pieces green. 
 
I did put some star washers on each side of the volume pot and encoder to help it cut into the metal a bit. I'll have to figure out some ground straps or something to ground the different chassis pieces together. 
 

 

Jack, W8TEE
 

Steve:

From what I can see, these should work fine. However, I'm starting to move away from encoder switches, as most of the stuff I build it QRP-oriented and small. As a result, the project doesn't have much mass, and I find that pressing an encoder switch requires me to hold the unit with the other hand to activate the switch, even with non-skid feet in place. I find myself using NO push button switches now, since they don't require as much force to activate. Just sayin'...

Jack, W8TEE

On Monday, February 24, 2020, 6:08:31 AM EST, Gigabyte <steven.b.hoff@...> wrote:


Evan, 

I only have a little MiniDSO 4 channel. It's this one here: https://amzn.to/32m1Qkr 
Not an electronics guru. I don't use my little scoped that often so I'm not great with it, but I checked it with the DSO. I was getting very bouncy readings on one side of it. It was very random. The other I was getting a regular dip to zero as I turned the dial. So I'm guessing the encoder is bad. 

Encoders look like they're cheap so I was thinking of ordering this pair of them from eBay: https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575553925&campid=5338625465&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F2X-EC-11-Rotary-Encoder-Digital-Potentiometer-20mm-Knurled-Shaft-with-Switch-USA%2F382783349631%3Fhash%3Ditem591faa637f%3Ag%3AzG4AAOSweEFcYvuH
Will that one I linked work? If so I'll go ahead and order as soon as I hear back from you if that's the correct kind to get. One of the pictures in the auction listing shows a diagram with resistors in it. I'm assuming this is what you were talking about there. 

I have several other Nanos, but they already have have headers soldered on the wrong side of the board. I'll have to get some more without the headers soldered on and solder headers on them. I'm really not the greatest at desoldering things, especially long rows of headers. 

Dean, 

My case isn't grounded right now. It's actually 6 seperate pieces of metal, so it will take me some work to get it all grounded well. This is the case I have: https://amzn.to/2HQEavb
 
The black part in my pictures (white if you look at the Amazon listing) is actually plastic. The front metal panel sits in the plastic. Same for the rear panel. The two plastic pieces on the ends are bolts to the bottom metal pan, and there are two metal rails at the top on each side. Then the metal cover that goes over the top and sides. It was blue and white like in the pictures on Amazon. I painted the plastic black and the metal pieces green. 
 
I did put some star washers on each side of the volume pot and encoder to help it cut into the metal a bit. I'll have to figure out some ground straps or something to ground the different chassis pieces together. 
 

 


--
Jack, W8TEE

Gigabyte
 

Thanks Jack. Do you have some links to the particular switches and/or encoders you like? 

Steven, N9FC

Jack, W8TEE
 

I think the Bourns encoders without switches are pretty good. The Mouser PEC11L-4120F-N0020 is a 20 ppr with no switch, panel mount with nut (many are not panel mount) for about $1.85 quantity 1. I buy the NO push button switches in bulk (e.g., Amazon B07BD2D96W) for about $.50 each. So far, I have had good luck with both.

Jack, W8TEE


On Monday, February 24, 2020, 7:47:51 PM EST, Gigabyte <steven.b.hoff@...> wrote:


Thanks Jack. Do you have some links to the particular switches and/or encoders you like? 

Steven, N9FC

--
Jack, W8TEE

Gigabyte
 

I'm happy to report it was the encoder.  I purchased this I linked from eBay and replaced it and it's working beautifully.  Now on to getting everything tuned up.  😃