NM0S 4-S Tuner


Aaron K5ATG
 

I have been troubleshooting my recently built 4-S Tuner. I'm hoping someone can help with ideas on where to look. 
At first, it did absolutely nothing at all. I noticed that the magnet wire needed a better job of scraping the enamel off so I did that. I touched up some solder pads here and there. Now during tuneup, there is a definite change in volume when adjusting the inductance and capacitance settings, however neither of the LED's light up. I have been looking at this thing until I am nearly cross eye and I can't find any obvious errors that I know I must be missing somewhere. 
Once again I would greatly appreciate any help. 
Thank you


 

Have you checked that the LEDs are oriented properly according to their anode and cathode? Since they’re placed through the board in an odd way, it may be possible to get them backwards. 


Curt
 

Aaron

If the controls are each changing the audio output of noise or signals in your receiver they are working. Very likely you fixed something with inductor insulation. 

A LED in different than a light bulb. Being a diode it only works one direction, with the clue that one lead is longer before installing. Matt has a good idea that it could be backwards. But mark one of the leads just in case it's okay. Insulation on its sense coil, likely a smaller toroid could also be not removed. See if you can check its continuity with an ohmmeter, but you may have to try both directions because of diode behavior. It needs to show zero ohms or very low both directions. 

Curt wb8yyy 


 

There “may” be a silk screened indicator of the orientation that the LEDs require. There is usually a line in the board that corresponds to the flat edge of the LED ridge. Not the LED bulb, that’s hemispherical, the ridge along the bottom has an edge that is flatter and is meant to be oriented towards that line. 


Aaron K5ATG
 
Edited

It was hard to notice but I got the red LED in backward, I will change that out. Green LED is correct. It threw me off because the green LED has the flat side on the left-hand side of the LED opening and the red LED has the flat side on the right side of the opening.

This is why it is wise to ask for help here. You guys make me notice stuff a lot faster than what I would have noticed on my own. 
Thanks a lot, everyone. 


Aaron K5ATG
 

I replaced the LEDs and made sure that they are in the correct orientation and went over nearly every solder pad. Nothing changed. I can change the audio from the transceiver using the controls and that is it. Neither LED will light up while tuning. I'm quickly nearing the limit of my patience with this tuner. I'm getting tired of wasting my time trying to fix something that does not want to work. I've gone over every component, every diode, every transistor. Everything is tight, not seeing anything close to a solder bridge. At this point, it just isn't worth the stress of the frustration of trying to figure it out. 


Johnny AC0BQ
 

Ge Aaron 
If you want to mail it to me I will take a look at it for you. 
No charge.
If I can’t fix it we will send you a new kit.
We have 100’s of these kits out there and they seem to work fine.
Let me know if you need my address.
73
Johnny ACØBQ 

On Fri, Aug 5, 2022 at 9:28 PM Aaron K5ATG via groups.io <k5atg=yahoo.com@groups.io> wrote:
I replaced the LEDs and made sure that they are in the correct orientation and went over nearly every solder pad. Nothing changed. I can change the audio from the transceiver using the controls and that is it. Neither LED will light up while tuning. I'm quickly nearing the limit of my patience with this tuner. I'm getting tired of wasting my time trying to fix something that does not want to work. I've gone over every component, every diode, every transistor. Everything is tight, not seeing anything close to a solder bridge. At this point, it just isn't worth the stress of the frustration of trying to figure it out. 

--
Check out the 4SQRP website at 4sqrp.com


Aaron K5ATG
 

Thank you for the offer. Could you send your address to k5atg.aaron@...


John - KK4ITX
 

Just AWESOME support !!

John
KK4ITX 

Visit:  www.zaarc.org.   👁

On Aug 5, 2022, at 22:37, Johnny AC0BQ <jomatlock@...> wrote:

Ge Aaron 
If you want to mail it to me I will take a look at it for you. 
No charge.
If I can’t fix it we will send you a new kit.
We have 100’s of these kits out there and they seem to work fine.
Let me know if you need my address.
73
Johnny ACØBQ 

On Fri, Aug 5, 2022 at 9:28 PM Aaron K5ATG via groups.io <k5atg=yahoo.com@groups.io> wrote:
I replaced the LEDs and made sure that they are in the correct orientation and went over nearly every solder pad. Nothing changed. I can change the audio from the transceiver using the controls and that is it. Neither LED will light up while tuning. I'm quickly nearing the limit of my patience with this tuner. I'm getting tired of wasting my time trying to fix something that does not want to work. I've gone over every component, every diode, every transistor. Everything is tight, not seeing anything close to a solder bridge. At this point, it just isn't worth the stress of the frustration of trying to figure it out. 

--
Check out the 4SQRP website at 4sqrp.com

--
John, KK4ITX       # 1603


Ted
 

On Fri, Aug 5, 2022 at 10:28 PM, Aaron K5ATG wrote:
At this point, it just isn't worth the stress of the frustration of trying to figure it out. 
This sounds like most of the projects surrounding my bench right now; I'd rather just go out and play with the units that work. I'd take Johnny up on his kind offer if I were in this position. 

72,

Ted
K3RTA


Tom Sevart
 

On 8/6/2022 06:09, Ted via groups.io wrote:
On Fri, Aug 5, 2022 at 10:28 PM, Aaron K5ATG wrote:
At this point, it just isn't worth the stress of the frustration of
trying to figure it out. This sounds like most of the projects surrounding my bench right now; I'd rather just go out and play with the units that work. I'd take Johnny up on his kind offer if I were in this position.

You haven't been homebrewing for long if you don't have a few projects which just refuse to work...


--
Tom Sevart N2UHC
St. Paul, KS


 

Well, I just bought one as well. I have built one before when they were green. This one is black and I have the same symptoms as the original poster. I’m going to swap both LEDs out with parts I already have and see if it’s a parts issue. 


WA0ITP
 

Hi Matt,
Can you get the red LED to go all the way out, or at least very dim?   Thats all thats really necessary. Its a great little tuner as is. 
GL . 

On Sat, Aug 6, 2022 at 10:27 PM Matt KC3CRU via groups.io <matthewmyates=icloud.com@groups.io> wrote:
Well, I just bought one as well. I have built one before when they were green. This one is black and I have the same symptoms as the original poster. I’m going to swap both LEDs out with parts I already have and see if it’s a parts issue. 

--


 

I get no light on either LED. Not when attached to an antenna or a 50 Ohm dummy. The dials affect the received RF signal, but when I switch it to “IN” and key to tune, no lights. 


 

Well, I reversed the polarity of the green LED and it lights up now. Still nothing on the red with either polarity. All the traces have continuity. No solder bridges, the coil has continuity with 0 ohms on all pins. I think I have the polyvaricons set to minimum (unmeshed), but the photo is different than mine. I’m quite flabbergasted unless we both overheated the same part and got identical damage?


 

I found my issue. The green led taking a reversed polarity made me think to take a look at all the diodes. I had D1 in reverse. I now have all LEDs in the polarity of the silkscreen and the unit works. I thought I had triple checked that diode! 

I figure I must have had it in the tweezers and set them down for a second and didn’t look at the polarity before installing. 


David Wilcox K8WPE
 

I bought one when they were first available.  Worked fine.  Sold it as had too many tuners…. Love building stuff.

Dave K8WPE

David J. Wilcox’s iPad

On Aug 6, 2022, at 11:27 PM, Matt KC3CRU via groups.io <matthewmyates@...> wrote:

Well, I just bought one as well. I have built one before when they were green. This one is black and I have the same symptoms as the original poster. I’m going to swap both LEDs out with parts I already have and see if it’s a parts issue. 


AB1DQ - James
 

A few notes based on my mileage...

First I built this tuner, and it is one of my favorite of my 4SQRP kits - and that's saying a lot!

I tend to spend way more time at the workbench than the operating bench as someone who grew up melting solder long before I got my ticket.  After 40+ years of building kits and scratch-building, and as someone with a less than average attention to detail, to this day, many of my builds are 'no joy' on the first pass.  It used to frustrate the heck out of me, and I'd abandon projects left and right.

Eventually I got to the point where I learned to accept and even embrace the often-needed troubleshooting phase.  I see it as part of the process and I think of the diagnosis and solving the problem not unlike solving a puzzle - which many folks do just for fun (go figure!).  The real upsides of troubleshooting is of course in the end, you get a usable piece of gear, but it also provides an opportunity to go deeper into the build - giving you an opportunity to better understand the circuit and to further your understanding of electronics.  Can it be super frustrating?  Yeah....  Do I have stuff that I never figured out?  Definitely....  But I never have a shortage of things in the workshop I can return to and futz around with.

This has been a great thread... I love how this community rallies to help.  Try not to lose hope and keep on trying!

73 de AB1DQ/James
www.ab1dq.com



On Sun, Aug 7, 2022 at 4:46 AM David Wilcox K8WPE via groups.io <Djwilcox01=yahoo.com@groups.io> wrote:
I bought one when they were first available.  Worked fine.  Sold it as had too many tuners…. Love building stuff.

Dave K8WPE

David J. Wilcox’s iPad

On Aug 6, 2022, at 11:27 PM, Matt KC3CRU via groups.io <matthewmyates=icloud.com@groups.io> wrote:

Well, I just bought one as well. I have built one before when they were green. This one is black and I have the same symptoms as the original poster. I’m going to swap both LEDs out with parts I already have and see if it’s a parts issue. 


William Franklin
 

What you gain from failure is experience.  Moral: Don't Quit!

73, Bill, K5WB


From: main@4SQRP.groups.io <main@4SQRP.groups.io> on behalf of AB1DQ - James <james@...>
Sent: Sunday, August 7, 2022 5:06 AM
To: main@4sqrp.groups.io <main@4sqrp.groups.io>
Subject: Re: [4SQRP] NM0S 4-S Tuner
 
A few notes based on my mileage...

First I built this tuner, and it is one of my favorite of my 4SQRP kits - and that's saying a lot!

I tend to spend way more time at the workbench than the operating bench as someone who grew up melting solder long before I got my ticket.  After 40+ years of building kits and scratch-building, and as someone with a less than average attention to detail, to this day, many of my builds are 'no joy' on the first pass.  It used to frustrate the heck out of me, and I'd abandon projects left and right.

Eventually I got to the point where I learned to accept and even embrace the often-needed troubleshooting phase.  I see it as part of the process and I think of the diagnosis and solving the problem not unlike solving a puzzle - which many folks do just for fun (go figure!).  The real upsides of troubleshooting is of course in the end, you get a usable piece of gear, but it also provides an opportunity to go deeper into the build - giving you an opportunity to better understand the circuit and to further your understanding of electronics.  Can it be super frustrating?  Yeah....  Do I have stuff that I never figured out?  Definitely....  But I never have a shortage of things in the workshop I can return to and futz around with.

This has been a great thread... I love how this community rallies to help.  Try not to lose hope and keep on trying!

73 de AB1DQ/James
www.ab1dq.com



On Sun, Aug 7, 2022 at 4:46 AM David Wilcox K8WPE via groups.io <Djwilcox01=yahoo.com@groups.io> wrote:
I bought one when they were first available.  Worked fine.  Sold it as had too many tuners…. Love building stuff.

Dave K8WPE

David J. Wilcox’s iPad

On Aug 6, 2022, at 11:27 PM, Matt KC3CRU via groups.io <matthewmyates=icloud.com@groups.io> wrote:

Well, I just bought one as well. I have built one before when they were green. This one is black and I have the same symptoms as the original poster. I’m going to swap both LEDs out with parts I already have and see if it’s a parts issue. 


Gwen Patton
 

David,
I remember that sale. I wish I'd bought that 4S tuner from you then!

Just ordered one. I have several other tuners, but this one looks to be very solid. I'm outfitting a couple of different go-bags, depending on what kind of operating I plan to do. I will keep my antenna lofting gear separate, as I only have one throw weight, one arborist line, and one line throwing bucket, but I can set up with different radios, different antennas, different tuners if necessary, etc. That way, if I want to go activate a park, I can take one kit, if I want to work QSO parties I can take another, digital operating gets a third, and a space where wire antennas wouldn't fit needs my Wolf River setup. And the smallest would be my Zachtek Flea, that travels in a repurposed pistol box. I plan to use a K6ARK end fed for that one!

But other than that, I just like the write up the 4S tuner for in CQ magazine this month.

73,
Gwen, NG3P