Messages

301

The RF Workbench / Re: HF Beacon, design questions

« on: June 10, 2020, 1619 UTC »

Yeah, FET's are cheap and efficient.  I wasn't sure what you were going to do with the relays (they're handy to have around) but without latch function, they're power hungry.

How much current are you switching?

302

22 Meter Band HiFER Beacons / Re: A little 22m opening circa 1700 UTC 8 June 2020

« on: June 10, 2020, 1615 UTC »

What modes, Chris?

303

Bacon, BBQ, Beef, And More / Re: Some experiments cooking bacon in the oven

« on: June 08, 2020, 1704 UTC »

EZ clean in the microwave.  Sammich it between a couple of layers of paper towels on a plate and spin till you're too hungry to wait.

Wipe plate of grease with the now-used paper towels, chunk 'em in the trash and enter BLT heaven.

304

Bacon, BBQ, Beef, And More / Re: Why is the World Health Organisation Anti-Meat?

« on: June 08, 2020, 1701 UTC »

Other than because they're an international leftist organization? 

305

The RF Workbench / Re: HF Beacon, design questions

« on: June 07, 2020, 2041 UTC »

Nice work! I like island construction too. It goes fast ...

306

The RF Workbench / Re: More beacon simplicity (and economy)

« on: June 06, 2020, 1745 UTC »

My order actually came in 4 days from the time I orderered to the time the programmed parts were on my doorstep.

Digikey is good!

Fun fact... the Digikey name came from the first product of the ham who started it. A Digital Keyer.

307

The RF Workbench / Re: HF Beacon, design questions

« on: June 06, 2020, 1742 UTC »

Yeah, I agree with CDS.... I'd be leery of anything like conformal coating.  It's a major PITA to deal with afterwards, it's rarely as inert as advertised and it's a rework/repair nightmare.  I think it's more meant to avoid condensation and dirt in industrial electronics rather than actual waterproofing.  Find an ammo box, or a plastic snap on container or the like to waterproof your electronics. There's lots of solutions for short money. The crappy part is, most waterproof containers are almost impossible to glue to when you need to.

I'd also consider putting more hysteresis in your undervoltage logic. If Vbattery is low, I'd sleep for an hour or so to get the voltage >> your threshold of concern voltage.  I'm thinking you want to stay further away from brownout conditions than the 8 sec tolerance.

Just my inexpert 0.02$!

** Edit- was looking at ATTiny specs last night and it looks like one can get the standby current in "sleep" mode down to the uA range!      I have some dev boards I'm going to play with for some keying functions.  I think there's 5 I/O's on those boards too.

Fun project!

308

SDR - Software Defined Radio / Re: Multiple virtual audio cables on one PC. Is it possible?

« on: June 06, 2020, 1733 UTC »

Just what I wanted to hear ! Thank you Chris

309

The RF Workbench / Re: HF Beacon, design questions

« on: June 06, 2020, 1509 UTC »

I'd have to look back at my notes, but as I recall that 27 mA range is roughly what I recall too.   There's a lot of opportunity to sleep the uP between transmit cycles, etc to save power .  Removing the LED is a winner too.   I can't recall what benefit underclocking might bring in regards power consumption , but switching loss is real, so it should help too.

You might look at the brownout detect functions too.


Added: The version without the microusb is yet less power hungry. IIRC I got it to sleep with a consumption of 2mA or so. 

 

310

SDR - Software Defined Radio / Multiple virtual audio cables on one PC. Is it possible?

« on: June 06, 2020, 1435 UTC »

While I'm migrating most of my SDR stuff to Pi's, there's times where it's handier to host them on a PC.  My question is, is there a way to create more than one Virtual Audio Cable (the software I'm using to pipe stuff around a PC between SDR's and software) in Windoze?

Thanks in advance for any advice .

311

SDR - Software Defined Radio / It aint over till it's over

« on: June 06, 2020, 1432 UTC »

John Seamonds of Kiwi (and this board) has volunteered to host and maintain the function, if other parties agree.

Thanks John!

312

The RF Workbench / Re: HF Beacon, design questions

« on: June 05, 2020, 2315 UTC »

There's a lot you can do with those $2 Nano's to reduce standby consumption. Simple things like turning off I/O's rather than leaving them active, as well as using the various sleep modes as well as turning OFF your transmitter Vcc when not transmitting.   It's pretty easy to make a voltage measurement of your battery and make some decisions on when to next transmit , or adjusting your transmit duty cycle,

My guess is that you might be able to do most of what you need with an ATTiny for even less power consumption. 

Also google charge controllers or charge controller circuits . THey're easy to find and cheap and made for this purpose.

You're building on a good ground plane. Yes, youll need to waterproof things!  This turns out to be trickier than first thought.

313

Equipment / Re: Receiver protection from nearby xmtrs

« on: June 05, 2020, 1733 UTC »

While the author in his article specifically mentions NOT to use PIN diodes (without saying why) I've got some 6V zeners that I'll make a BTB connection with for this purpose.  I've got an amp worth 1300 watts out, and I'd like to not zorch my SDRs when I forget to disconnect 'em.

314

SDR - Software Defined Radio / Re: Linear power supply for KiwiSDR & others, fan cooling

« on: June 05, 2020, 1559 UTC »

I'm using an open frame linear, dual output supply off of Ebay. Took a while to get one that works  (shipping damage)and I replaced a couple electrolytics while I had it on the bench.  These things were built to last.   I made a bottom section for it, so I could add individually fused feeders for the 12V and 5V lines along with some coaxial power jacks, since it was not as nicely packaged as your Lambda.  I added a screen on the top to keep from electrocuting myself, my wife or the cat and also bonded everything to the Al ground plate in hopes of keeping noise down. There's a second Kiwi in there now, and BCB and FM notch filters before the splitter and homebrew distribution amp. An aluminum top plate sandwiched to a 1x10 pine (the same sandwich as the rest of this is made from) forms the top of this (not shown)





I think these commercial linear supplies run warm as they're designed  with a significant resistive load in order to keep the regulation pretty tight between load and no load events.   Lambda makes good stuff, and you got a bargain!

315

The RF Workbench / Re: Making a cheap eBay RF Power Amp Sorta Work

« on: June 05, 2020, 1343 UTC »

How did it work? Any better than Chris's mini space heater?