开云体育

Removed one leg from L502 and still had short to ground on both primary and secondary of the T501. I removed it and currently rewinding.

On Wed, Apr 23, 2025 at 06:59 AM, Jared N7MAW wrote:

I'd call it workable, but not really enjoyable

I feel the same.? With QRP I find it necessary to switch transmit slots often (since there's always someone who can't hear you and chooses to transmit in your slot).? And finding a new slot in FT8CN seems a lot harder to me than in WSJT-X.? The automation often gets in the way too.

?

73, Mike KK7ER

?

Jamie, glad to hear? that all went well.

?

If I remember correctly, you installed C17 with a switch to bypass it.? Whenever C17 is switched inline, RF detection will be active and work without a PTT cable installed.? If C17 is inline and a PTT cable is installed, both will be active!? I had mine wired this way for a while and Allison recommended to remove C17 to avoid possible QMX finals damage.

?

For the QMX, bypass C17 and just use PTT.? If you mistakenly use only RF detection with the QMX, it will transmit once and stop until you power cycle the QMX as we both found out.

?

Wiring in the C17 and bypass switch adds flexibility if you want to use the amp with different rigs.? Since the QMX is my only QRP rig, I opted to leave C17 and the switch out.? It is easy enough to add if I find a need to do that in the future.

--

73,
Jim - AE5JE

That should have read ‘short between primary AND secondary of T501’?

A short between the primary or secondary of T501 or Q507 is shorted and the fault is elsewhere. Lifting one end of L502 and measuring continuity to ground, as suggested will point you in the correct direction.?

Nick G0OQK

Nate,

?

I have used an Android phone with FT8CN and a QDX for about a dozen POTA activations. I'd call it workable, but not really enjoyable. But I'm not about to lug a laptop or tablet into the backcountry ?. I recommend trying it at home first to learn some of the quirks with the app before an activation. It seems much more automated by default compared to using WSJT-X.

?

Jared, 73, N7MAW?

I’d also like a full kit if/when you do an arcing group buy. My email is good on QRZ.

?

BrianB N6CVO

狈6颁痴翱蔼补谤谤…..

What band is this?

L502 has continuity to ground. I've removed the finals too. The short is still there on 12v.

Before unsoldering L502 check if it has continuity to ground, if it doesn’t, the fault isn’t in the PA or modulator.?

It is probably easier to unsolder one end of L502 and checking, before leaping in to unsolder the finals. Check the board carefully for any solder whiskers.?

Nick G0OQK

On Wed, Apr 23, 2025 at 01:46 PM, Muhsin TA1MHS wrote:

(JS8 for android anyone?)

did anybody tried this?, please let me know

?

73 DE muhsin TA1MHS

I noticed when doing the mic leveling that I got louder peaks when I wasn't pressing the PTT button on the external mic, but the actual output when transmitting is based on the levels when pressing the PTT button. So the tool "hears" the external mic differently depending on the PTT switch position, but it's not a simple on-off.

--

73, Dan - W2DLC

Hi?
I modified my QDXs so they can work with 5 Volts from the USB of PC, tablet or phone.
With FT8CN now I can run a minimum system from my phone/tablet
Power is about less then a watt, so you can call it QRPp.
My BS170s are safe now with prolonged WSPRs, FT8s or JS8s (JS8 for android anyone?)
73 DE muhsin TA1MHS
?

Summary:

When there’s a solar flare.. go mow the lawn.

Oh, my. Then you're going to spending time on the main board. Lots of places to look. I'm sorry.

Something easy - just unsolder the finals. After that, if the short is still there, it's a matter of tracking it down.

It's a pain to troubleshoot SMD, I know. I design it every day and I hate troubleshooting my own designs. I always pray I didn't make any mistakes. LOL.

The 12v short is without the boards installed.

Wow, that's not good. And if you unplug each power supply one at a time? Need to find out which one is blown. They both have the +12vdc going to them.

Hi Everyone

?

Thanks for all you advise and comments on my low power issue on my newly built QCX+ for 60 mtrs. After a lot of time playing around with the LPF I decided to restore all the toroid values to those in the assembly instructions, and then just removed 2 turns from L3 and my power went up from 1.5 watts to 2.5? watts, using 13.8 volts. I played with the coil spacings but was unable to improve the output so I have decided to leave it with a 2.5 watt output.

Thanks for all your help and hope to catch you the wireless soon

73 Keith G4TJE