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?many thanks!!!

Thanks for info.
Wondering if you had a similar solution for the lpf?
Joe
VE1BWV

I'm a greenhorn as well so take what I say with a small siberian salt mine, but I seem to spend most of my time on 40m anyways. ?You will definitely lose some capability being single band, but you will also be very power efficient, and with a few modifications, you can get a full 20W out, much more than most SOTA rigs. ?It seems a workable solution to me.? There are also mods to multi-band, but those are beyond me.

I do think a $300 antenna is overkill. ?You are running a single band, so I would cut a simple inverted V dipole, or maybe an end fed half wave with a Sotabeams pico tuner or similar.

I would start with the dipole. ?They say that as a beginner it's easier to make an antenna worse than a dipole, but hard to make one better.

I made a homemade version of the YoYoTenna out of two $4 Coghlan's Laundry reels. ?The reels are a bit hefty, but it packs up really nice and you can adjust it for multiple bands if I want - I cut it for 40m at full extension, and as long as I use it with the BitX40, I can just roll it out all the way to stake it. ?If I bring a different radio, I reel it in to spots I marked with a sharpie for whatever band I want to use.

Hi all,

I have done some experimenting with RFSIM, modelling the existing BPF, and analysing it. I have come up with an easy way to have some filtering, without just shorting out the BPF.
If you put a 470pf from the antenna input to the junction of L3 and C6, you will get a reasonable BPF at 80m.
Change it to a 6.3uh inductor , and you will get 30m. A 2.2uh will give you 20m.
These are not optimal as in the original nice 40m BPF, but an easy way to get at least some filtering from BCB and higher up. See attached pics.
P.S I have tried it, and it works great.!
Cheers

John de VK4KWT

Hi all,

Extreme newbie here. I recently received a BITX40 and installed the pavelmc sketch from??.? I added a function button on A3 and GND (orange and yellow wires respectively from the Raduino 8-pin harness). Usually when I first turn the radio on the button will work a few times but eventually the button stops responding until I unplug everything and let it sit for a while, then on next power up it will work a few times again.

I checked the continuity from A3 to GND while pressing & releasing the button and it seems to be working as expected.? Also the same thing happens if I take the button out and just short A3 to GND.

I'm not sure what to look at next.? Keeping in mind I'm a novice at understanding circuits, my only guess is that maybe the internal pull-up resistor for A3 isn't getting turned on or isn't working correctly and allowing A3 to float instead of being pulled high?? However the sketch I'm using does appear to enable the internal pull-up for this pin, so I'm not sure if that's it or what else it could be.

Any other suggestions? Thanks.

Jason - W4JAL

Joe,

?? I have taken mine to a few places had a great time with it cw/ssb/digi. I did put mine in a metal case and use a pelican for travel it fits pretty tight and has some added weight but works out pretty good. Phone will be a bit tough for the next few years but is more than doable.

I use either my homebrew slight inverted V 40m dipole or I have used in the last few trips out. I do plan to put my bitx on 40m/20m but is still a work in progress.

Below I am at Mackinac Island last summer didn't get much but prop that day was pretty rough still was a great time and awesome view.

?

73

?? Happy building

David

??? N8DAH

?

?

?

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I buy 1K and 10K by the hundreds. So that's what it gets. Buy the way,

Raj > is correct. One or 2 ma on the newer LEDs is usually bright
enough. I go

1K on 5V and 10K on 12V for some reason.

I buy all my resistors by the hundreds. At Tayda they're only a penny or
less each. Doesn't cost much to have a good stock of the common values.

Vince.
--
Michigan VHF Corp.

The Nano board has a diode that prevents your PC from getting fried.

After a raduino fry up! there was a short that smoked that diode in the nano and I pulled the plug in time
and that got me thinking and came up with a solution.

Raj

At 06-11-2017, you wrote:

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I buy 1K and 10K by the hundreds.? So that's what it gets.? Buy the way, Raj is correct.? One or 2 ma on the newer LEDs is usually bright enough.? I go 1K on 5V and 10K on 12V for some reason.

Another thing, if he uses a Dual LED, only one resistor is needed from the common cathode to ground. ? But because of the color, Red will probably be the brightest.? Might require going to separate resistors.? For learning sake, one should put your DMM in current mode? measure and try 1-10K for brightness and current.? Then measure the forward voltage for each resistor of the LED.? See how little it changes.

Mike, WA6ISP

My rule, for 12v I will use a 12K resistor for LEDs.

Considering todays LEDs brightness I must increase that value.

At 06-11-2017, you wrote:

Using 680 ohms will really make the LED bright.?? I = (12V - 3.3V ) / 680.?? Most work real nice on just a few ma.?? 2.2K should give nearly 5 ma.?? What folks are saying is an LED is not "operated" or "biased" with voltage.?? You put a current thru them, and the voltage is just a result.?? You get what you get!

The current limit resistor is picked for how bight you desire it to be.? ?? The 3.3V spec will be the approximate voltage drop at a given current.

If you were running on a battery, you might try only 1 or 2 ma.

Just a thought, most take 20 ma. OK.?? For an experiment, try 10K and then 1K???

Mike, WA6ISP

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

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I have that diode on all my RaduinoX boards.? The other thing, I have left the 12V on my test fixture on many times while programming with the USB (by Mistake).? I have been Lucky.?? I? know the rule is not to have two 5 V supplies going!

I have never blow a Nano so far.

Mike, Lucky

Folks,

This morning I was working on a bitx with raduino. While connected to the PC for uploading a sketch I noticed
the board was still receiving a station albeit at a lower volume. Then it occurred to me that 5V from USB
was flowing back to main board. This reverse flow through the 7805 can damage it and fry the raduino.

Put a 1N400x or similar from the main board 12V wire with the "arrow" towards the raduino.
Anode to main board -> cathode to raduino or the line bar on the diode towards the raduino.

This will not be required if you are not going to update your sketches.

Cheers

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

My rule, for 12v I will use a 12K resistor for LEDs.

Considering todays LEDs brightness I must increase that value.

At 06-11-2017, you wrote:

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I did that on an old (1.09) Allard Version.? I made a tuning function with the same name as he has.

I can switch back and forth with the conditional assembly.

It works but I don't get any of the functions with the Push Button that use some other functions that involve the pot.

Like Calibration and such.? So it is a hack, in needing of lots of attention to get the options with the Push Button.

I moved the frequency change directly into the interrupt, I seemed at the time to have to much lag setting and reading an interrupt flag?

Still sometimes it seems to jump 2 steps when I tune.? I got pull-ups and 0.01uf de-bounce on the encoder.? Since the encoder

has resistors and my RaduinoX has them, I need to experiment with them at a higher value.? I think it is 10K in both place, meaning 5K pull-ups.? I may take them completely off or go up on the caps.? I use it for now.? I also have NO dynamic step changes.? The encoder bump switch sets 4 levels of steps.? I have it boot up at 1 KHz?? I know Jack has some fancy code for that.

Mike, WA6ISP

Allard :?

The only way I could see that you could cram in support for an encoder for tuning would be via conditional compilation.?
i.e. something like :?

#if defined (ENCODER_TUNING)
? ?// code for encoder ?
#else
? // code for tuning pot?

Since you either use the pot or an encoder for tuning, not both, ?this would potentially work ?but it has the disadvantage of cluttering the code up
and making it a bit more convoluted.?

The default could remain as tuning pot to maintain compatibility. Anyone wanting to use an encoder would need to?
uncomment a define for ENCODER_TUNING (or whatever you would call it) so that code is compiled and used instead.?

Cheers

Michael VE3WMB?

P.S. My idea doesn't consider the necessary pin assignments needed for the encoder and the encoder switch, which might conflict with?
existing PIN usage on the Nano. Since this might involve PIN reassignments, my suggestion would be to defer any?consideration for this
until Raduino V2.?

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

Allard :?

The only way I could see that you could cram in support for an encoder for tuning would be via conditional compilation.?
i.e. something like :?

#if defined (ENCODER_TUNING)
? ?// code for encoder ?
#else
? // code for tuning pot?

Since you either use the pot or an encoder for tuning, not both, ?this would potentially work ?but it has the disadvantage of cluttering the code up
and making it a bit more convoluted.?

The default could remain as tuning pot to maintain compatibility. Anyone wanting to use an encoder would need to?
uncomment a define for ENCODER_TUNING (or whatever you would call it) so that code is compiled and used instead.?

Cheers

Michael VE3WMB?

P.S. My idea doesn't consider the necessary pin assignments needed for the encoder and the encoder switch, which might conflict with?
existing PIN usage on the Nano. Since this might involve PIN reassignments, my suggestion would be to defer any?consideration for this
until Raduino V2.?

I posted this question to another forum and didn't get much support for the idea, so I figure I'll ask here:

"I'd like to get involved with some of the OTA groups -- Michigan's three year Parks On the Air, etc. I have ideas for my mobile station in my VW camper, but I'd like to put together something I can use when hiking etc. Here's what I am thinking.

Make a BITX40 in a Pelican case like this:?

For an antenna either buy or clone a packtenna:?

My only concern is being limited to 40m. I haven't had my ticket long, but so far it does seem like 40 does get activity during the day around here (which is when I'd be using the mobile setup).

Workable OTA contesting pack rig or should I think about another radio?"

I should have added that I am learning CW, so phone operation is important for the time being anyway.

Thanks for your input!

Joe

Folks,

This morning I was working on a bitx with raduino. While connected to the PC for uploading a sketch I noticed
the board was still receiving a station albeit at a lower volume. Then it occurred to me that 5V from USB
was flowing back to main board. This reverse flow through the 7805 can damage it and fry the raduino.

Put a 1N400x or similar from the main board 12V wire with the "arrow" towards the raduino.
Anode to main board -> cathode to raduino or the line bar on the diode towards the raduino.

This will not be required if you are not going to update your sketches.

Cheers

--
Raj, vu2zap
Bengaluru, South India.