We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissable in your locale.

Author Topic: Stretchyman 40w GaN TX is sick  (Read 3789 times)

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 507
  • Karma: +21/-33
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #15 on: October 04, 2019, 1105 UTC »
"Its not all "unicorns and fairy-free," it costs money to ship it there and time/work to pack it up to send it on an international journey as well as the time without a transmitter".

So for the $30 it will cost to send it back, you can't be bothered?  + time without a TX, er.... it doesn't work!

I cant see the logic there, at all.

You can't test a FET with a multimeter (def not this one as it's got two devices in one package) I could go on, but wont....

I've tried my best, I'm not going to force you to send it back.

Good luck.

Stretchy.

'It's better to give than receive' so why RX when you can TX!

                            Buy one from me, NOW!

Great discounts on ALL my transmitters if purchased via HFUnderground


                                              ;)

Offline Antennae

  • Hero Member
  • *****
  • Posts: 634
  • Karma: +2/-0
  • CA, USA
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #16 on: October 04, 2019, 1646 UTC »
Dude, I ain't lyin' or tryin' to slander you, Stretchypants.   ::) 

I'm a member of a shortwave pirate forum and I've got my own conspiracy theories about you and your extraordinary repair policy, so there.   ;)

Here's a nice video of the method I used to test the mosfet with my multimeter:
https://www.youtube.com/watch?v=tL7bQuJaXKA

California Coast
RCVR: Radio Shack DX-398 portable, remote SDRs 
Antenna: usually a random wire with tuner

Offline JimIO

  • Sr. Member
  • ****
  • Posts: 491
  • Karma: +4/-20
  • QTH I.O. MA
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #17 on: October 04, 2019, 1752 UTC »


 ...and I've got my own conspiracy theories about you and your extraordinary repair policy, so there.   ;)

Here's a nice video of the method I used to test the mosfet with my multimeter:
https://www.youtube.com/watch?v=tL7bQuJaXKA


Gotta love (not) the stand w trump and epoch times ads you get when you click that link.    8)

~

Offline redhat

  • DX Legend
  • ******
  • Posts: 1387
  • Karma: +32/-4
  • USA
  • Music is my drug.
    • View Profile
    • Email
Re: Stretchyman 40w GaN TX is sick
« Reply #18 on: October 04, 2019, 1818 UTC »


 ...and I've got my own conspiracy theories about you and your extraordinary repair policy, so there.   ;)

Here's a nice video of the method I used to test the mosfet with my multimeter:
https://www.youtube.com/watch?v=tL7bQuJaXKA


Gotta love (not) the stand w trump and epoch times ads you get when you click that link.    8)

~

Serves you right for not running adblock
Somewhere under the stars...
WinRadio Excalibur/305 w/ a chi-town resonant loop, Kenwood KDC-U356 for mobile listening.
Please send QSL's and reception reports to xfmshortwave [at] gmail [d0t] com

Offline JimIO

  • Sr. Member
  • ****
  • Posts: 491
  • Karma: +4/-20
  • QTH I.O. MA
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #19 on: October 04, 2019, 1951 UTC »
"Serves you right for not running adblock"

For now I'll just wait a bit then click skip ad.

I need to figure out why in firefox after 67 the override colors does not work first.

~


'


Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 507
  • Karma: +21/-33
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #20 on: October 05, 2019, 0836 UTC »
As already stated the internal structure of the GaN FET is not standard and is CASCODE and contains 2 devices. It can't be tested using the method stated. The fault has nothing to do with the FET anyway.

Str.
'It's better to give than receive' so why RX when you can TX!

                            Buy one from me, NOW!

Great discounts on ALL my transmitters if purchased via HFUnderground


                                              ;)

Offline Antennae

  • Hero Member
  • *****
  • Posts: 634
  • Karma: +2/-0
  • CA, USA
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #21 on: October 05, 2019, 1600 UTC »
Well, for posterity's sake, my old one didn't pass the test and my new replacement did pass the test.  And you mentioned there are 2 devices in the FET, that would make sense because I heard multiple pops...before it stopped.  R.I.P.
California Coast
RCVR: Radio Shack DX-398 portable, remote SDRs 
Antenna: usually a random wire with tuner

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 507
  • Karma: +21/-33
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #22 on: October 05, 2019, 1908 UTC »
Please if anyone has any problems with any of my products please send it back immediately.

I can assure you it will be a swift turnaround and at minimal cost.

Please don't mess around and waste your time (and mine) as has happened here.

Stretchy.
'It's better to give than receive' so why RX when you can TX!

                            Buy one from me, NOW!

Great discounts on ALL my transmitters if purchased via HFUnderground


                                              ;)

Offline JimIO

  • Sr. Member
  • ****
  • Posts: 491
  • Karma: +4/-20
  • QTH I.O. MA
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #23 on: October 06, 2019, 0258 UTC »
 ..that would make sense because I heard multiple pops...before it stopped.  R.I.P.

Troubleshooting tip: Turn the PS off just before you hear the first pop.    8)

~
« Last Edit: October 06, 2019, 0301 UTC by JimIO »

Offline OgreVorbis

  • Full Member
  • ***
  • Posts: 137
  • Karma: +0/-0
    • View Profile
    • DosaidSoft
    • Email
Re: Stretchyman 40w GaN TX is sick
« Reply #24 on: October 06, 2019, 0927 UTC »
I'll bet the problem is that one of the NCPs is fried.

My newer transmitter uses those NCPs and I fried a lot of them during the testing process. Yes, it is best to apply the low level voltage first and then the HT after.

But Stretchy knows what he's doing and probably has good symmetry and square waves.

I fried so many of those NCPs when I was designing mine. Just a tiny bit off in symmetry or a slightly rounded wave will make those things bake themselves really fast.

I doubt there is a problem with Stretchy's transmitter as he's been doing this a long time. I just don't like those NCPs very much, they're not any better than the 614s and they can't dissipate heat, so if there is a small problem, you're screwed. Maybe it's better in the long run though because it won't allow you to be sloppy. Even in optimum conditions, you can't apply more than 15V to them.
Radio and Programming Blog: http://dosaidsoft.com/wp/

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 507
  • Karma: +21/-33
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #25 on: October 06, 2019, 1603 UTC »
In my design I drive a GaN FET with 8V, I fact it's fine with just 6V. The NCP drivers are perfect and barely get warm.

Please can everyone stop guessing what's wrong with this Tx. I suspect because A.C. has been applied momentarily, everything had fried. I know the op has stated there's only 5V arriving at the RF PCB and there should be 12V.

The op has decided to refuse my offer to fix it for free, let's leave it there shall we.

I'd rather not spend anymore time with this thread.

The End.

Hopefully....

Str.
'It's better to give than receive' so why RX when you can TX!

                            Buy one from me, NOW!

Great discounts on ALL my transmitters if purchased via HFUnderground


                                              ;)

Offline ChrisSmolinski

  • Administrator
  • Marconi Class DXer
  • *****
  • Posts: 26050
  • Karma: +55/-45
  • Westminster, MD USA
    • View Profile
    • Black Cat Systems
Re: Stretchyman 40w GaN TX is sick
« Reply #26 on: October 06, 2019, 1615 UTC »
You're free to ignore this thread, Stretchy, as the original poster, and others, are free to continue it. We can always learn something  :)

In my design I drive a GaN FET with 8V, I fact it's fine with just 6V. The NCP drivers are perfect and barely get warm.

Please can everyone stop guessing what's wrong with this Tx. I suspect because A.C. has been applied momentarily, everything had fried. I know the op has stated there's only 5V arriving at the RF PCB and there should be 12V.

The op has decided to refuse my offer to fix it for free, let's leave it there shall we.

I'd rather not spend anymore time with this thread.

The End.

Hopefully....

Str.
« Last Edit: October 06, 2019, 1619 UTC by ChrisSmolinski »
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 300 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 507
  • Karma: +21/-33
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #27 on: October 06, 2019, 1859 UTC »
Not the end then....?

Str.
'It's better to give than receive' so why RX when you can TX!

                            Buy one from me, NOW!

Great discounts on ALL my transmitters if purchased via HFUnderground


                                              ;)

Offline Antennae

  • Hero Member
  • *****
  • Posts: 634
  • Karma: +2/-0
  • CA, USA
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #28 on: October 06, 2019, 1948 UTC »
Its not over 'cause the OP's in da house, woot woot!

To prevent AC with my 24V AC to DC power supply, if I were to have a second go at it, I would wire in 2 x 12v lightbulbs so they make a 24v load to the power supply.
So my sequence would go like this:

Turn on PS and make sure my 24 volts worth of lights are powered on
Make sure xmtr is off
Then plug PS into transmitter
Then turn on xmtr and start calling CQ

That way I figure the PS would be producing DC before it goes into the transmitter. 
California Coast
RCVR: Radio Shack DX-398 portable, remote SDRs 
Antenna: usually a random wire with tuner

Offline JimIO

  • Sr. Member
  • ****
  • Posts: 491
  • Karma: +4/-20
  • QTH I.O. MA
    • View Profile
Re: Stretchyman 40w GaN TX is sick
« Reply #29 on: October 06, 2019, 2106 UTC »
Wut  ;D kind of PS is it that you would need to do that?

Antenna: usually a random wire with tuner

Is that wut ;D you use to TX?

~