开云体育

The first suppl I bought a Tekpower TP3005T works fine except when used my QCX. The fan in the power supply changes speed at the one amp level and the affect is when you key the unit the fan goes to

Sorry for the late reply. I'm going to put in the 1N4148 some day just because I know myself too well, and it's cheap 'N easy. RE: I figure it's no worse, since I did keep the washer clamping. I

Yeah exactly, Nick, if we **knew** 15dB down at second harmonic is adequate, I could have nicer passband like Ross's for 17-10m LPF. My attitude here is that I can over-build now and slack later.

I certainly *WOULD* call Hans a professional. He has sold more than 20,000 sets with the PA you are rubbishing. Most manufacturers can only dream about that number. Ted 2E0THH

Absolutely. Heat generally decreases MTTF and make the device more susceptible to other threats but heat alone is only a gradual and slow-acting cause of failure. In case of general purpose switching

Nice try, I never said that. Those are fragile, too. Be careful making a categorical statement like that. GaN RF transistors are very durable and many of them may be more durable than 6146, although

Wow — this is EXACTLY the kind of info I was hoping for. Thank you!! -Tom N6QDI

I have been using the very similar, probably identical inside but less expensive, Tekpower linear TP3005T supply since

This is the go-to supply for my lab, I have 5 of them.? There is also a programmable version, KD3005P for a small price increment.? They are also sold by/as SRA Soldering Products, Micro Centers

I can confirm that I had a "very similar" (if not the same) problem when I used a poor power supply. This actually happened twice: The first time was a connector problem - the 2.1x5.5 was not in all

Hi Nick, Yes, my traces look incredibly low tech. I still use those numerical design tables at the back of filter theory books and my HP calculator to design filters, so NanoVNA V2 Plus 4 is a bit

Hi Andy Whether or not you're right (and fwiw I'm sometimes more than mildly surprised at the technical ideas expressed by people with callsigns) I've noticed over the years that in effect calling

Follow up, the mouser part I ordered does not fit.? It is 1mm too large at the base and shorts out the PCB holes.? Still looking.

Hi Allison.? If only I'd known that as a teenager in the late sixties.? I saved up for an age to buy a 12AT7 when I had a bucketful of 12AU7s from televisions donated by family and neighbours. When

Anyone seen this problem? I am running WSPR on my QDX using WSJT-X and a Raspi. I am running bandhopping (80/40/20m), and set the WSJT-X schedule up ticking the TUNE option for each band I am

Tom, I would affirm Lex's recommendation of the Korad supply.? I got it as a Christmas present from my wife in 2022, and I find it meets all the requirements.? It is also available on Amazon for us

Thanks Hans I still have a QDX enclosure fulfilled with a burnt QDX? now it has a future?

Hi Robert, QMX uses a similar Class D PA. I think same mod should work fine. The only issue is there isn’t much real estate to place pa mod daughter pcb unless we ditch the case. 73 Barb WB2CBA

A good portion of that assembly time will be spent winding toroids, checking the turns count, checking the tap is correctly located, double checking and triple checking, then correcting turns count

Just a quick note. Please, consider that building the QMX kit takes time. Before receiving it, I thought it would take me a couple of hours of work. It ended up taking me about.. 6-8 hours. I'm not a