Is still available I’m keen to use 80m for the first time

73 John M7FZC

I've been trying the hardware diagnostics with no BS170s installed and all the Rx tests behave as if there's no test signal input.

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The Receiver is working.? I connected an antenna and can hear and decode FT8 signals.

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I would expect that the receive tests would work, the Audio Filter Sweep, RF Filter Sweep, Image Sweep and Test ADC I/Q.

AIUI none of these use the Tx side, they use a test signal provided by CLK2 injected into the Rx chain through R518 don't they?

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Could CLK2 not be working?

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The MS5351 must be working because Rx works, at least for CLK0 and CLK1.

The voltage on all the BS170 gates goes from 0 to just over 2V when transmitting and the drain pins go to the input voltage. I guess this means that CLK2 is OK and that ICs 501, 502 and 503 are OK.

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Have I missed something?

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Chris, G5CTH

Ja,

So, based on your scans I would immediately suspect the soldering of the T501 transformer, and your LPF toroids. Maybe also the winding of T501.?

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73, Dan - W2DLC

I use these:

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John AE5X

Dear Stan, Please give me some advice.
I tried sequentially inputting signals from 7Mhz to 21Mhz to My QMX using Tiny SA. I was able to receive everything.
So I think replacing PCM1804 should be prioritized rather than rewinding T401 or L401a/b. Is this idea wrong?

I want to minimize damage to the PCB.

Today, I asked a store in Akihabara-town in Japan to order PCM1804. There was no shipping charge, but it was little expensive.

Mitsu JK1PDR

80m QCX mini with AGC unit fitted excellent condition. I built this to use in the QRP section of the RSGB club contests where it performed very well, only used a couple of times and never portable...in excellent condition.

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Yours for ?50 plus postage

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73 Steve G4EDG Exeter

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g4edg@...

Forgot about this, good call!

HI John.
Where can I get the flipup feet you have on your QMX+?

Thank you.
73 DE DK4BN

On Tue, Nov 19, 2024 at 10:47 AM, Barry VA7GEM wrote:

There is very cheap way to do this. Pick up some flake Shellac and mix with Alcohol then paint it on.

I just use folded paper towel. After you have painted 5 to 6 times you can just wipe with alcohol between prints.

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Wow--that's one I've not tried yet, Sadar! I've tried? more adhesion promotion candidates than most users though. I like Magigoo--at least the original version I tired, but I really like how one version of Vision Miner Nano Polymer Adhesive works with just about all FDM polymer materials. The only two materials that Vision Miner says don't work are POM and PP. I've never printed POM and I have another adhesive for PP that's sold by the PP filament manufacturer.

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I was experimenting with ATU EEPROM cell codes today. Don't make the mistake of, thinking it's a PIC, accidentally plugging an ATMega chip into a PICit3 and trying to program it with your Arduino sketch! (My aging eyes make this kind of error increasingly likely.)? The ATU will still work---a little, but the communications between PIC and ATMega are obviously borked, due to some kind of ATmega I/O port damage. I tried reprogramming the damage ATmega to no avail. A programmed new one fix the ATU though! Things could have been worse. I could've damaged my PICkit 3 instead of just a $2.88 ATMega chip!

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73,

Cal (AD8Q)

I just tried to download the firmware. ?The display is just a row of blocks. ?And when I clicked and dragged the file into E:QMX. it appeared to download. ?But nothing doing with turning rig on and off. ?I think all the parts are in the right place. ?Any suggestions where to start. ? I will resolder that horrible row of 16 pins again. ?Thanks.

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I did replace the variable resister that changes the brightness as I accidentally touched the original one with the iron and pooched it. ?The resister does make it lighter and darker blocks. ?yeah.

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Has anyone used a speaker from a smart phone for any electronic projects?

Examples

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Thanks

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George

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Looks like I have found a workable solution:

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Two issues here:

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1. MAX745 multi cell lithium battery charging board - not sold in Amazon. Only available through eBay and aliexpress with long delivery time.

2. I had a brief email exchange with Hans. The booster might (will?) create noise (RFI?). So, this will need to be tested.

3. Diode for circuit separation is OK, but relay is better.

4. Adding all these together along with BMS will inflate the total cost for the battery charging.

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Any thoughts?

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73,
Sardar (AC8L, 4K6SA, VA3DUA).

I use an Oontz? ?...? inexpensive and pretty good fidelity.?

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Bruce K1FFX?

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There is a Line in terminal on the radio. If you connect it from the QCX-mini's Audio terminal, the AUX display will appear on the V115 and it will function as a speaker. You can record.

Mitsu JK1PDR

Very nice, always enjoy what you have to say about QRP.

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John

My QMX does not behave that way.? S meter always works on all bands in CW mode only.

But I don't have the highband version, I have the midband.? I suppose there could be some quirk in the firmware related to only the highband version, but it could be also something with your particular unit.? I would try a Factory Reset, which would get rid of any unfortunate bit left set in the config parameters, to see if that helps.? And I would go into the Hardware tests and run SWR scans on all of the bands, and see if they are consistent on 10m - something in the hardware could have an unfortunate resonance around 10m which causes some havoc with the SWR reading circuitry that locks it up.

Thanks Stan,

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You are quite correct. ?

The itemized parts list on page 19 of the manual indicates BN61-202. ?I was basing my search and query on the parts pictorial on page 24 of the manual which shows it as BN43-202. ?
I know: “read the manual!”?

So, I’ll trust the parts list and your input and start looking for the BN61 cores. ?
Searching for the correct cores should make it considerably easier.

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Thanks very much for your help.

Cheers

Dan VE7CTN?