Thank you for the advice. I already have a bunch of low pass filter boards from kitsandparts a few years back, so just need the bandpass units. I was looking at the qrp labs board, so that may be the way I go. I do have a signal generator? frequency counter, and scope, so should be able to set things up with that.

Brent

Hi,

Over the months I have published a number of minimal hardware mods that are required for certain added functionalities in the Raduino software.
I noticed it is sometimes confusing and hard to understand which mod is required for which function. For this reason I've made an overview that hopefully makes things a bit more clear:


The mods themselves are explained in this document:


73 Allard PE1NWL

The Raduino has a 5V regulator to drop the voltage for the Nano soldered in.

Raduino takes the same 12V that the BITX40 takes but brings it down to 5V.
By mistake if you connect or a oops moment put 12V on 5V line then its a goner.

Thats what John is saying!

Raj

At 21/10/2017, you wrote:

12v on the Nano will destroy it.

Thats confusing unless I'm missing something. The wiring diagram shows +12v to orange wire on raduino and black to ground

OK, folks - Tuning clicks conquered!
Reading back on earlier messages here, it seems the regulator 7805 deserved some attention. I had fed this via 51E to drop a few volts and 'take some heat', and put a 220uf electrolytic across its output thinking it would absorb the current spikes from the Arduino as it changed state. Given the severity of the spikes as at my last missive, it didn't, so in further experimentation I tried clip-leading a 1000uF across the 7805's input and the clicks disappeared. OK, I thought, that 220uF is doing no good where it is, let's try that on the input. Bingo! Just for good measure I put a 10nF (103) disk - just what was to hand still from the old PC PSU - across the 7805 output anyway.
I've left it at that for the night. It seems the audio is more stable too, and I've heard my first valid signals! Digital stuff down the bottom of the band. Hope is on the upsurge!

73 all, de ZL2DEX

Dex,

Put a 1K to 10K in the brown lead going to the volume control. That should get rid of the hum. It results from LM386 getting
unstable.

Raj

Bill N2CQR wrote...

I thought you would all be interested in this
beautiful video. The Quantum Indians

So, if half of the BITX40 is made of Bosons, does
it mean the other half is made of Fermions? It's
all over my head. I just turn it on and it works.
All the electrons know exactly how they are supposed
to jiggle and when.

Bose, Raman, Saha and their fellow scientists were
very smart cookies. We should probably include
Ramanujan in that group.

"The chief thing is to take some pleasure in your
work."

Ummm... was it Raman or Farhan that said that? hi!

--
73 Keith VE7GDH

It's a SMT 1N4148. It can take about 1.5A forward current
before overheating and giving up the ghost. It is a cheap and common
diode if you have to replace it. If the reversal was short enough, most or all
of the other parts survived, except maybe the Nano. Check it very carefully
with a meter to know what voltage is where. 12v on the Nano will destroy it.

There seems to be some confusion about + and - and the wire colors.

In the USA black is the "hot" lead for AC VOLTAGES, white is the neutral or return
and green is the common ground. Traditionally, for DC VOLTAGES, red is the
positive lead and black is the negative lead (maybe there is a green for ground).
Of course, homebrewers use whatever is handy...

I am not sure what the EIA standard is but probably brown and purple are involved.

Be careful; the BITX convention is not standard.

The best fix is a 1N4004 diode or better at the source point of all your voltages.
That way a reverse voltage is rendered harmless to the board being examined.

Been there, done that.

john
AD5YE

开云体育

Nothing special, just a 4148 I believe.

Wow I actually did have the voltage backwards. I was trying out this down converter with 4 18650 batteries and they have the negative out labeled as positive. Does anyone know the specs on that diode??

D7 is in the VCC line right next to the relay K1.
Check your wiring. It seems likely that you applied
12v to the Nano (or reversed the polarity), which probably fried it.

If K1 coil is open, then the 12c would be applied
directly to D7 as the load at that point. Maybe that's
what took out the diode...

john
AD5YE

开云体育

Bottom left corner of schematic. Are you sure you don't have the power hooked up backwards?

I forgot to ground the black wire on the arduino. When I plugged in the power D7 started smoking. I pulled the power grounded the black wire (one next to the brown) then tried again and it started smoking again. Do yall think changing D7 will fix it or did I really screw up? I was trying to find d7 in the circuit diagram to see what it is but it's like looking for waldo.

Greetings, all ...

I have replaced my banjaxed raduino. It ran on the original firmware, and I'd applied several fixes to the Bitx40:
?- better biasing for Q16
?- N2CQR's active filter replacing R113 (worked a treat to knock back the tuning clicks)
?- 1k Vol pot wiper to U1.3
?- D7-K1 back-emf mod
?- I7SWX's de-thump AF clamp (modded to delay release on Tx-Rx)
?- 1N400x +12 to U1.6

All seemed stable until the 'fat-fingers' slip that killed the raduino ... although I got to hear my old sig.gen and a 'birdie' or two, I didn't actually hear decipherable audio ...

Meanwhile another 'fat-fingers' slip killed U2, so the new raduino's CLK0 is now driving Q7 base. There's plenty of audio, so Q8 and Q9 seem to be redundant with raduino tuning, though I still haven't actually heard decipherable audio ...

I've been struggling with hum. A major contributor was the power supply I've been using (linear 13.8V with seemingly defunct diode in the bridge), so I'm now running from a switcher (ex-USB-DVD external drive). There's still hum intermittently, but I've narrowed that down to stray pick-up from the raduino's CONTROLS loom. I still haven't connected any switches and 'stuff', so the wires as supplied are still there, but tucking them down against the metal (earthed) chassis-tray of my (otherwise plastic) housing has put that in the background. Should all unused lines here be defined with pull-ups at power-up unless otherwise assigned?

I've noted that with my ultimate aim of encoder tuning, the tuning pot? will become redundant and A7 usable elsewise ... perhaps taking on D4's duties to free that up for the enconder's 'bump switch'?

Now having installed Allard's latest firmware (first time and painless) I find the tuning clicks back with a vengeance. N2CQR's active filter seemingly no longer effective versus tuning clicks ...

... and there's tuning drift. It would seem that the si5351 is being controlled in 50Hz or less steps and the display only indicating each 100Hz. Is that 100k pot too high an impedance for the raduino's input? The originally-supplied 0.1uF (104) cap is connected as before wiper-to-ground, so I'm mystified ... with multiple clicks heard per displayed change (while not touching the pot.), is there a temperature effect?

I've read that rapid discharge of +RX on TX (and vice versa?) might be beneficial. I wonder if/how this might be implemented at K1 - transistor clamps controlled from opposite contacts? Not tried, just conjecture ...
RX->TX, clamping the Rx line: D18 in the +RX line will leave C110 powering the Rx audio - what purpose does it serve? and could it be bridged? or maybe do the clamp at C110 rather than at K1 contacts? +12 has left the RX side to power the TX after all - or does de-powering U1 produce its own thump?
TX->RX, clamping the Tx line: no 'great thumping' electros or diodes, so should clamp cleanly at K1.

73 de Dex, ZL2DEX

开云体育

I still have lots of Raduino X bare PCBs and completed boards.? In case you blew up stock Raduino or want to make alternate projects.
I have sold about 30, but ordered 50 PCBs.

For those wanting a Raduino board.
There is a better option than the orginal Raduino board with it Soldered
- in Nano.
RaduinoX? PCB designed to add some features.

I have Lots of Bare PCBs and some assembled and tested.? Lots of Bare PCBS!

Several sold to guys in this group.

I used this board, LCD, and Rotary Encoder to make a nice dedicated RF
signal generator.


1) I wanted to be able to plug Nano in and out, not soldered. I wanted
the USB connect next to the side of the cabinet so I can program without
taking the lid off.? I will make a small hole.

2) Added, diode protection, more filtering and conditioning on the power
input.? Regulator is bolted down.

3) Added a dedicated connector for Rotary Encoder with pullups and
bounce capacitors.

4) Added an I2C connector.

5) I wanted proper Level Shifting to the Si 3V part.? Added FETs and
pullups for that.

6) Added D0 and D1 pins on PCB.

7) Kept power and VFO connector on 5P header so no changes to my present
wiring was necessary.

8) Put contrast Pot where you can get to it.

9) Complete documentation.

10) Fits original LCD perfectly.


Take a look if you are interested.
motdog@verizon dot net

Mike, WA6ISP

Hello, All;

My BITX40V3 Raduino just went "Tango Uniform"... Display is blank, (blocks only), no control of tuning, will not accept a reload of the sketch. COM port seems ok.
Anybody have a spare they're willing to part with?? Can use PayPal.

Thanks,
Bruce, K7BHB

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

I bought a BitX40 a while back with no intention of using the Raduino. It's still in the bubble wrap. $30 shipped prio conus. Email me direct if you're interested. vev at michvhf dot com

Vince.

--
Michigan VHF Corp.