Re: Possible PA low output problem.
On Sat, Feb 4, 2017 at 12:47 pm, Jerry Gaffke wrote: How would you solve the issue of some new ham with a voltmeter and a Bitx40 that doesn't quite work? If I were to advise a new ham with just a voltmeter, I'd tell him he needs to learn to walk before he can run, and that if he wants to get into home brewing he should start with something less challenging--for instance a DC receiver kit with a good track record of successful builds. Then maybe get an Arduino and monkey with that a while. Get it to display his call sign on an LCD, play with one of the ADC channels to read the value of a pot, stuff like that. Then get an Si5351 board from Adafruit or Etherkit or QRP Labs and get it to make some RF. He can verify it's working by using the receiver he built. By now, he (or she) is getting excited because there's been some accomplishment feedback (always positive, never negative) and some sense of making headway. So now he has a signal source and he knows a little MCU programming. Now maybe he can make a simple diode peak-detector type RF probe, and if he wants he can use the ADC in his Arduino to display the probe's reading (compensated in software for the non-linearity of the diode). I suppose he could even get an AD8307 and read the output of that with his Arduino (once he learns a little about logarithms--a Wikipedia article will do for starters).
In the meantime, he's reading everything he can get his hands on about common-emitter biasing, double-balanced mixers, low pass filters, and the difference between resistance and reactance. Before he's hardly aware of it, he's off and running. He might buy one of those cheap-but-good-enough LC meters from China, and if he was still taking my advice I'd suggest he consider springing for an inexpensive oscilloscope--even an old analog one. This will kick his experimenting, testing, and troubleshooting capabilities into high gear.He'll at least know he'll need an SWR/Wattmeter and he might even put one together. They're nice, simple little projects.
*Now* he can take the BitX40 off the shelf and know enough and be equipped enough to make a go of it, and in place of newcomer frustration and discouragement will come some real satisfaction.? That's how I would solve the problem of some new ham with a voltmeter and a Bitx40 that doesn't quite work. 73, Todd K7TFC
|
Hi bitxers,
Some have said they hear a click or perhaps a chirping on keying ptt, my bitx40 is no exception. When the ptt is pressed, the relay Rly1 is activated first, the +12tx line is enabling the microphone amplifier Q12 before rx audio Q16 has time to be disconnected by Rly2 (contacts M1 & M2) , therefore the microphone amplifier is active before the transmitter switching has completed hence a burst of feedback.
If you delay power to the microphone amplifier allowing Rly2 to settle
the "chirp" which is audio feedback does not occur.
As a test I disconnected resistor R127 which provides power to Q12 microphone amplifier and inserted a 2n7000 fet as a switch inline with r127 with a RC delay on the gate, chirp has now gone, it's not the most elegant hack so hope some one can came up with a better solution.
best 73 Alf vk2yac
|
Re: adjusting the contrast on the LCD
Got it John. and that is why my second post immediately. ?regards ?sarma vu3zmv
|
Re: adjusting the contrast on the LCD
He speaks of the LCD that came with the Radiuno. It was broken and replaced. As far as
I know, none of the lcds come with the contrast pot mounted on the lcd itself. I am sure
there are some somewhere...
The contrast pot is mounted on the Radiuno board next to the mcu. It is mounted on top
of the board and is hard to adjust with the LCD in place. It really should be accessible from
the bottom of the board.
I made up a universal mounting plug-in board for breadboarding with a contrast pot, a
7805 filtered supply, and male and female headers so that I could use any lcd (except
those with double row connectors), All the pins are brought out so that they are accessible
from the breadboard. It's pretty handy.
john
AD5YE
|
Re: adjusting the contrast on the LCD
Yes It is the same pot., Jack.
all the best sarma ?vu3zmv
On Sun, Feb 5, 2017 at 9:08 AM, Mvs Sarma <mvssarma@...> wrote: I generally manage with a 1K resistor or a single 1N4148 diode , with cathode facing ground.
?So far it has been working well for me. I do use model JHD162? modules.
|
Re: adjusting the contrast on the LCD
I generally manage with a 1K resistor or a single 1N4148 diode , with cathode facing ground.
?So far it has been working well for me. I do use model JHD162? modules.
On Sun, Feb 5, 2017 at 9:01 AM, Jack Purdum via Groups.Io <econjack@...> wrote: Most have a square pot on the back of the display. Not so with yours?
Jack, W8TEE
I had to replace the LCD that came with the radio.? The new LCD has its contrast set too high.? Does anyone know how to change this?? Is it the blue and white pot next to the arduino??
|
Re: adjusting the contrast on the LCD
Most have a square pot on the back of the display. Not so with yours?
Jack, W8TEE
From: "davidzdeb@..." <davidzdeb@...>
To: [email protected]
Sent: Saturday, February 4, 2017 8:16 PM
Subject: [BITX20] adjusting the contrast on the LCD
I had to replace the LCD that came with the radio.? The new LCD has its contrast set too high.? Does anyone know how to change this?? Is it the blue and white pot next to the arduino??
|
Re: lcd 3.5 display help sought
The four push buttons are used to control the frequency and its increment. One button allows you to move the cursor above the field that you wish to change. When you get it above the field that you wish to change, you push a button to set it to that field. The encoder can then be rotated to change the field. Truth is, that's a pretty clunky way to do it. In fact, the only reason is because that's the way the VFO code is set to work.?
I use a process that I call Fast Tune. When you are just "tuning around", you rotate the encoder at a fairly slow rate and the frequency changes at a rate set at the current increment value. Let's assume it's 100Hz. If I tune slowly, like you do when you are zeroing in on a frequency, each detent of the encoder is +/- 100Hz, depending on CW (+) or CCW (-) rotation. But suppose you want to move from 7.280 to 7030 to listen to CW. In the video, you're going to have to do a bunch of button pushes to change it to a large increment (e.g., 10KHz) and then, when you get near the CW band, more button pushes to drop the increment back to 100Hz so you can zero in on the frequency you want.
With Fast Tune, as soon as you start moving the encoder shaft rapidly (and you can define in software what "rapidly" is), the software senses the rate of turn on the encoder and immediately and automatically changes the increment to 10KHz (or whatever rate you have set in the code). Keep turning it quickly and the increment stays at 10KHz. However, as you approach your target frequency and you slow the turn rate down, the software senses that and drops the increment back to the "slow" rate of 100Hz (or whatever you have set it to). The default tune rate can even be changed at runtime via an encoder shaft press. No more press-a-button-move-to-the-digit-rate-button-press-rotate-the-encoder-to-the-frequency-button-press. Just move and go.?
If I were you, I'd use Fast Tune in a heartbeat. The code for Fast Tune can be found in my article in the April issue of QRP Quarterly.
Jack, W8TEE
From: Art Olson via Groups.Io <olsonaj6927@...>
To: [email protected]
Sent: Saturday, February 4, 2017 5:23 PM
Subject: [BITX20] lcd 3.5 display help sought
I have been following PD8W (Willem) progress on his build out of a lcd display/si5351. His code and hardware are listed at PD8W.com. After some hard work I have the display working - and looks like his does on his web site. I am at the point where he is using momentary pushbuttons to cycle selections from the screen however am a bit lost as to how the buttons are actually wired up. I sent him a couple of requests for help but he must be out of town as I haven't gotten and feedback. Could someone take a look on his web page to see what I need to do? The sketch is also there and like I said it compiles. My first issue to overcome what understanding how to wire the lcd and found that in the mcufriend ino. Woohoo the display showed up on the lcd. Let me know if you need anything further. Note - I did hook it up to the bitx and the encoder does change freqs so that part is also working
73 Art
|
Only one of the out of 6 I belong to show the UPLOAD button.
73 Ken
On Sat, Feb 4, 2017 at 8:36 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: Have been several folks complaining of not being able to upload files.? Searching for "upload" in these messages, appears the problem started on Feb 1 somewhere between posts 21263 and 21280. ? Good to have a thread for this. ?
On Sat, Feb 4, 2017 at 05:25 pm, Ken wrote:
I am trying to upload to the group files, but no UPLOAD button. ?
|
Additional BPF's for other Bands
A few weeks ago I uploaded LTSpice plots and schematics for other bands, 80m 60m and 20m.
I finally got some time to build the 20m BPF. Even though the plot was good, the BPF did not work. I double and triple checked connections and components, but no go.
So I pulled out the bible (EMRFD) and read up on TTC, triple tuned circuits. I haven't down this kind of math since the 80's and it was beyond me.
Low and behold on Page 6.77 Figure 6.135 was a chart of L's and C's for different bands. So I built the 20m version and it works great.
Once the UPLOAD button comes back, I will load the plot and schematic to the files.
Meanwhile if anyone is interested, I'm attaching ?a plot and schematic.
73
Ken VA3ABN
|
Seems the upload stopped around the latest Groups.IO update. Oh well.
73 Ken
On Sat, Feb 4, 2017 at 8:36 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: Have been several folks complaining of not being able to upload files.? Searching for "upload" in these messages, appears the problem started on Feb 1 somewhere between posts 21263 and 21280. ? Good to have a thread for this. ?
On Sat, Feb 4, 2017 at 05:25 pm, Ken wrote:
I am trying to upload to the group files, but no UPLOAD button. ?
|
Have been several folks complaining of not being able to upload files. ?Searching for "upload" in these messages, appears the problem started on Feb 1 somewhere between posts 21263 and 21280. ? Good to have a thread for this. ?
On Sat, Feb 4, 2017 at 05:25 pm, Ken wrote: I am trying to upload to the group files, but no UPLOAD button. ?
|
Re: adjusting the contrast on the LCD
Yes,
This really should be mounted on the other side of the board for cases like this.
It would require a slightly different pattern, but it could be done as is.
Ash?
It shouldn't take much adjustment to show data instead of bars,
but one end or the other of the pot travel will show bars, The proper adjustment
is not too far from that point.
john
AD5YE
|
I am trying to upload to the group files, but no UPLOAD button.
73
Ken VA3ABN
|
adjusting the contrast on the LCD
I had to replace the LCD that came with the radio.? The new LCD has its contrast set too high.? Does anyone know how to change this?? Is it the blue and white pot next to the arduino??
|
Re: Using STM32 board with Arduino IDE
The stm-2 board with the modified Adafruit drivers are much faster. Here is a Youtube video showing the difference.
After I get a couple of projects finished, I will probably redo the SNA Jr to use this larger display and a stm 32 board.
DuWayne KV4QB
--
DuWayne? KV4QB
|
Very much on topic for me, thanks! ?So getting sent to ACS is to be expected. ?Guess I'd better go check that mailbox. In my case, the final 4 zip digits may be a bit superfluous. ?A county of over 3000 sq miles, under 8000 residents.
On Sat, Feb 4, 2017 at 04:03 pm, John Backo wrote: All foreign mail has no zip+4 code on it which is used for routing and delivery in the US. It is all routed (via image) to ACS for US routing. ?
|
Re: lcd 3.5 display help sought
Rob
Found it in my reference book. Thanks
Art
Sent from my iPhone
toggle quoted message
Show quoted text
On Feb 4, 2017, at 7:24 PM, Art Olson via Groups.Io < olsonaj6927@...> wrote:
Rob
Initially just the 40 m version. I am looking down the road to a multiband at some later date. Thanks for the info. Time to get my reference book out to review. So with the switch closed vcc is connected to the encoder or ?
Art
Sent from my iPhone On Feb 4, 2017, at 7:09 PM, G4NQX < tasmod@...> wrote: Ooops should read pulldown as diagram. Most of the code at the moment is display stuff. The icon.h can be deleted I suspect as it was development penguin pic but i didn't spend time looking too hard at the code. It could do your head in ! Are you using this on the bitX as is, or are you building a featured multiband bitx.
--
Rob G4NQX
|
Gidday Randy Attached the circuit here. ?Audio not so scratchy and more mellow. Ugly construction is very fiddly but it works. ?Take the red lead off the volume pot and attach AUDIO IN. Attach AUDIO OUT to the volume pot where the red lead was. ?The +12V connection can reach the switch. You have to run a ground wire to the 12V input socket - ground. ?Cost me $AUD8.00 for two sets of parts, resistors? came in packs of 10. Have fun - Noel
|
Re: lcd 3.5 display help sought
Rob
Initially just the 40 m version. I am looking down the road to a multiband at some later date. Thanks for the info. Time to get my reference book out to review. So with the switch closed vcc is connected to the encoder or ?
Art
Sent from my iPhone
toggle quoted message
Show quoted text
On Feb 4, 2017, at 7:09 PM, G4NQX < tasmod@...> wrote: Ooops should read pulldown as diagram. Most of the code at the moment is display stuff. The icon.h can be deleted I suspect as it was development penguin pic but i didn't spend time looking too hard at the code. It could do your head in ! Are you using this on the bitX as is, or are you building a featured multiband bitx.
--
Rob G4NQX
|
Todd K7TFC
DuWayne Schmidlkofer
