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Messages - syfr

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301
The RF Workbench / Re: HF Beacon, design questions
« on: June 14, 2020, 2034 UTC »
You transmitting into a 50 ohm load at both 4 and 8 Mhz?

302
The RF Workbench / Re: HF Beacon, design questions
« on: June 13, 2020, 2358 UTC »
That's looking really nice, and I'll look forward to listening for it.

that output filter sure neatened up that waveform!


303
The RF Workbench / Re: HF Beacon, design questions
« on: June 12, 2020, 2150 UTC »
Really nice work. And it works which is even better!

Congrats. That's a really nice looking transmitter .   When Im debugging/building something new it usually ends up looking like a dogs breakfast.   You did a nice job


304
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?

305
What modes, Chris?

306
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.

307
Other than because they're an international leftist organization?  8)

308
The RF Workbench / Re: HF Beacon, design questions
« on: June 07, 2020, 2041 UTC »
Nice work! I like island construction too. It goes fast ...


309
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.

310
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!

311
Just what I wanted to hear ! Thank you Chris


312
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. 

 

313
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 .

314
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!

315
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.

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