I came across an old '80s project box with a circuit board and lcd display perfect for the ubitx... However I am finding very little documentation on the SEIKO M4032 LCD display...?
Any information or relative info on the display would be greatly appreciated... I would like to use this LCD as it could display alot of information and fits the existing window...
Thanks,
Glenn VE3JAU
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Re: ND6T AGC implementation for uBIT-X
I've sent the paypal account money for 1 of each.
In case the address didn't make it:
Ron Herring W7HD
10270 W Mars Rd
Tucson, AZ 85743
On 05/23/2018 12:53 PM, Kees T wrote:
OK, the pass 2
boards have arrived, they look good so, let er' rip.
Ordering instructions are in the attachment and a copy is in the
Files section under my call. Not sure how all this is going to
work out due to the qtys ....let's see.
Please remember I'm still only one retired guy sitting at one
table.
73 Kees K5BCQ
--
Ron W7HD - NAQCC#7587 OMISS#9898 KX3#6966 LinuxUser#415320
Editor OVARC newsletter
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Re: toggle for low output and max output?
#ubitx
On Wed, May 23, 2018 at 05:29 pm, K9HZ wrote:
Relay switching of RV1 is on the website.?
That is a much more elegant way of doing what I was thinking with duct tape and bailing wire. Looks like the problem wasn't the idea but my potential execution ? --
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Re: RF power chain mods and improvements..
Allison, what i am seeing in my 'proto' build of driver stages only, using MPSH10's, is a flat response within 1dB BUT that's with relatively low drive levels using the Rigol at -20dBm input.
If I up the SA output level to around -2dBm (~150mVrms) which I think is the nominal level driving these stages, then the response is much worse.?? I also see severe +ve clipping levels at the base of the Q92 etc stage.
Using the sig gen (HP8640B) to drive the driver stages with 150mV, I get around 500mW out at 7MHz, rapidly dropping as the frequency rises.? Clearly, as you have said, the stages just can't deliver enough power to the FET's over the whole range.
Unfortunately I don't have any 2N3866's here but do have a few 2N4427's i could try. (500MHz Ft only though)? For the 2N2369 stage (Q90), I have the PH2369 which appears to be the same part.
Does the clipping I am seeing in the final driver stage, mean that stage needs to be re-biased with the 2N3866's?? If so what did you use?
Also, have you investigated what levels come out of the Modulator Vs frequency? It will also need to be relatively flat also for driver mods to work.
glenn
vk3pe
toggle quoted message
Show quoted text
On Wed, May 23, 2018 at 08:35 am, ajparent1/KB1GMX wrote:
Testing note..
How I arrive at the issue of gain vs frequency.
One was on paper using the well know EMRD feedback amp spreadsheet.
Every try said not possible unless the device has a FT of greater than 600mhz
THe simple test is we need a gain of 39 (~16db at 3mhz) and at 30mhz we need?
a device Ft of not less than 1170mhz based on the Ft/F rule of thumb.? We can
however get away with a bit less with only a small decrease in gain.
The other was a mod to the board and measure:
I removed the IRF510s and added a trans former to go from the gate connection
to 50ohms (1:1), added 10db 1W pad for safety (protect the Rigol). and to keep the?
mosfet out of the test.
Lifted C1 to isolate the TX amp from the LF and hooked a piece of coax with a.1uf cap at the and to
the input of Q90.??
RV1 set to 100% so we see total stage gain.
Enabled TX mode with out Raduino, jumper T/R to 12V..
Set up RIgol DSA 815Twith tracking generator for -20dbm output from 3 to 30 mhz.
I didn't do a screen capture though I should have.
( I used lower drive as I'd seen gain compression in driver and pre-driver at higher
output levels at higher frequencies. this is device HFE related at higher currents.
this makes the system look worse.)
The result was about 45DB gain at 3mhz falling to 34db at 30mhz. A drop of nearly 10db.
The slope of the curve was such that at about 7mhz we were already dropping by 2db.
Power out of the driver for that setup was .255 Watt at 3mhz falling to .023W at 30.
We could get more power by cranking up the trancking generator output at lower
frequencies but gain compression at higher power levels limited us at?14mhz and
above.
Adding emitter caps and inductors to the feedback helped but the result was still
well short.? The net effect is the curve was flatter to about 13mhz then resumed?
sloping down.
Why is this.? The 2n3904 has a FT of 300 (nominal) and the rule of? thumb is ft/f=Beta
BEta is the maximum attainable gain for the stage.? So at 3mhz the result is 100, lots
of gain and its tamped down with feedback to 39 (~16db).? ? At 30mhz the result is 10!
10 is 10DB of gain...? ?Paralleling transistors is supposed to help that but the result is
typically a 3db improvement at higher frequencies. So for 4 stages at approximately
16db per stage at 3mhz showed?48db (Not allowing for transformer losses) but close
to the result of 45 DB gain.? ?However at 3mhz we are supposed to get 30db and
did get 33 so we are doing better than predicted?but well down from 3mhz.
Adding the various caps and inductors in the feedback to the q90, pre-driver, driver made
the curve flatter but at 14mhz we are now 3db down and would end up at 35db down at?
30mhz.? Clearly the 2n3904s were not cutting it.? Its hard to get more than? a beta of 20
out of two in parallel and we need an effective beta of at least 39.
This is why higher frequency transistors that work at higher currents are being pursued.
Devices with FT greater than 650 mhz gets use within about 3-4db without circuit tricks.
3Db flatness means at 3mhz say 10W and 30mhz 5W.? Adding tapered feedback helps
some so we should see near 7-9W at 30 and so far my results confirm that using
2n2369 for Q90, and the pre-driver one 2n3866,? and driver two 2n3866.? ?All of those
have an Ft of 600mhz or so and power handling suitable for the stage they are in.
The problem is 2n3866 and 2n5109 are not cheap.
NOTE: if as was, we get about 4W (at 30mhz) from the IRF510s with the measured drive
it confirms the MOSFET is being starved!.
Putting the irf510s back in and grabbing the 50W 30db power attenuator agrees
nicely as the IRF510s at 3mhz were netting about 16db of gain and at 30mhz a
respectable 14db of gain.?
Conclusion is we need uniform gain and the ability to deliver more than .5W
(about .7 would provide good headroom).? ?The IRF510 has enough gain.
Now I wait for lower cost parts.
Allison
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I agree that setting the IDE set up to compile and program can be tricky, but once you get a good setup, it works just as smoothly as native Arduino parts. The Pill? I'm using seems to have a Maple Mini USB bootloader and the compiler identifies it as a 128K part, but I haven't tested that.
I have a souped up version of the stock uBitx code that has an ILI9341 main display, an ILI7735 S-meter display, interrupt-driven encoder and a 10khz interrupt driven A/D audio sampler for the S-meter and AGC control. I'm using libraries from Roger's repository. Everything runs very fast and silky smooth tuning with the 400ppr encoder. I still have to check out EEPROM functionality, but I'm confident the community will work out any issues. The thing I like about the Pill is that it can be my new 'go-to' board for 'throw-away' projects. I can afford to keep a dozen of them around and not have to worry if I damage or destroy one.
I have my souped up Raduino Pill board about 75% complete, waiting for final routing changes as I keep tweaking the schematic. However, all work will stop when I leave town for 3+ weeks this Sunday.
Joe
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Re: RF power chain mods and improvements..
Would the 2n5109 work in all the stages or is the 1W dissapation a problem? tim ab0wr On Wed, 23 May 2018 08:35:36 -0700 "ajparent1/KB1GMX" <kb1gmx@...> wrote: Testing note..
How I arrive at the issue of gain vs frequency.
One was on paper using the well know EMRD feedback amp spreadsheet.
Every try said not possible unless the device has a FT of greater
than 600mhz THe simple test is we need a gain of 39 (~16db at 3mhz)
and at 30mhz we need a device Ft of not less than 1170mhz based on
the Ft/F rule of thumb.? We can however get away with a bit less with
only a small decrease in gain.
The other was a mod to the board and measure:
I removed the IRF510s and added a trans former to go from the gate
connection to 50ohms (1:1), added 10db 1W pad for safety (protect the
Rigol). and to keep the mosfet out of the test.
Lifted C1 to isolate the TX amp from the LF and hooked a piece of
coax with a.1uf cap at the and to the input of Q90.??
RV1 set to 100% so we see total stage gain.
Enabled TX mode with out Raduino, jumper T/R to 12V..
Set up RIgol DSA 815Twith tracking generator for -20dbm output from 3
to 30 mhz. I didn't do a screen capture though I should have.
( I used lower drive as I'd seen gain compression in driver and
pre-driver at higher output levels at higher frequencies. this is
device HFE related at higher currents. this makes the system look
worse.)
The result was about 45DB gain at 3mhz falling to 34db at 30mhz. A
drop of nearly 10db. The slope of the curve was such that at about
7mhz we were already dropping by 2db. Power out of the driver for
that setup was .255 Watt at 3mhz falling to .023W at 30. We could get
more power by cranking up the trancking generator output at lower
frequencies but gain compression at higher power levels limited us
at?14mhz and above.
Adding emitter caps and inductors to the feedback helped but the
result was still well short.? The net effect is the curve was flatter
to about 13mhz then resumed sloping down.
Why is this.? The 2n3904 has a FT of 300 (nominal) and the rule of
thumb is ft/f=Beta BEta is the maximum attainable gain for the
stage.? So at 3mhz the result is 100, lots of gain and its tamped
down with feedback to 39 (~16db).? ? At 30mhz the result is 10! 10 is
10DB of gain...? ?Paralleling transistors is supposed to help that
but the result is typically a 3db improvement at higher frequencies.
So for 4 stages at approximately 16db per stage at 3mhz showed?48db
(Not allowing for transformer losses) but close to the result of 45
DB gain.? ?However at 3mhz we are supposed to get 30db and did get 33
so we are doing better than predicted?but well down from 3mhz.
Adding the various caps and inductors in the feedback to the q90,
pre-driver, driver made the curve flatter but at 14mhz we are now 3db
down and would end up at 35db down at 30mhz.? Clearly the 2n3904s
were not cutting it.? Its hard to get more than? a beta of 20 out of
two in parallel and we need an effective beta of at least 39.
This is why higher frequency transistors that work at higher currents
are being pursued. Devices with FT greater than 650 mhz gets use
within about 3-4db without circuit tricks. 3Db flatness means at 3mhz
say 10W and 30mhz 5W.? Adding tapered feedback helps some so we
should see near 7-9W at 30 and so far my results confirm that using
2n2369 for Q90, and the pre-driver one 2n3866,? and driver two
2n3866.? ?All of those have an Ft of 600mhz or so and power handling
suitable for the stage they are in. The problem is 2n3866 and 2n5109
are not cheap.
NOTE: if as was, we get about 4W (at 30mhz) from the IRF510s with the
measured drive it confirms the MOSFET is being starved!.
Putting the irf510s back in and grabbing the 50W 30db power
attenuator agrees nicely as the IRF510s at 3mhz were netting about
16db of gain and at 30mhz a respectable 14db of gain.?
Conclusion is we need uniform gain and the ability to deliver more
than .5W (about .7 would provide good headroom).? ?The IRF510 has
enough gain.
Now I wait for lower cost parts.
Allison
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Re: ND6T AGC implementation for uBIT-X
Hi Kees,
a query/suggestion on your DX postage:
Here in Aus I can use a DL envelope to a thickness of 5mm, just sent as an Airmail letter.
I have been using this method for my VK4PLN boards to send them DX at a cost of AU$3.50 for the postage.
Could you not do the same with these? Or have a board only option with letter postage for those with a stock of SMD...
Thanks Nick VK4PLN
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Re: RF power chain mods and improvements..
Also, what about these for the drivers?
73.
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Re: toggle for low output and max output?
#ubitx
Relay switching of RV1 is on the website.?
Dr.?William J. Schmidt - K9HZ
On May 23, 2018, at 2:15 PM, ajparent1/KB1GMX < kb1gmx@...> wrote:
No matter how you do it it will require hardware with my mods or no.
The easy solution is hard to implement as the places to put it are scarce
and they must be in the TX only path.
The most seemingly likely is two RV1 pots with a relay to select the one you want
and a button on the front panel to activate the relay during transmit.? Problem is
where to put the RF parts so there? aren't dragging wires all over and causing havoc.
The most obvious place is? near the edge next to K1. or as a flying PCB with a
relay, diode, two RV1s that drops into the old RV1 spot and two flying wires for
switching.? Lots of assumptions for space to place things.? Using a tiny relay helps.
Allison
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Re: BITX QSO Afternoon/Evening, Sunday, May 20, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.
Calling CQ bitx on 7.277, Heard VE3THR earlier. I will be here trying for a while.?
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Re: RF power chain mods and improvements..
You results so far are in agreement with what Glenn VK3PE has found, see his posts: /g/BITX20/message/44289Great work. Ill be keen to see how you go with the MPSH10/MMBTH10 in the drivers... 73 Nick VK4PLN
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Re: toggle for low output and max output?
#ubitx
I am experimenting with replacing RV1 with a 31dB, RF step attenuator board from SV1AFN.?
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No go on the brown wire. I also tried 4 letter words and crying. Moving on to whiskey until the nano gets here. Thanks for the suggestion tho
I did pull the raduino out and booted it standalone. It still showed only the firmware. Would it get locked in factory mode?
Thank you! I thought about that. I tried reverting to the original firmware and it was the same. Was tempted to disconnect the entire encoder but left it as is. Will give it a shot.?
On Wed, May 23, 2018, 2:34 PM John < vk2eta@...> wrote: Hello Sam,
There is a good chance your Raduino is likely working and you have an issue with the encoder.
Since it displays the version at start and nothing more after that it certainly looks like you have the push-button locked or shorted in the down position.
In the factory firmware and the KD8CEC firmware (at least the version you are using), when the push-button is held down at start-up it first waits for the button to be released, then it enters Factory Alignment mode. That's why I suspect the push-button input is held down permanently.
Easy test is to just disconnect the brown wire from the Raduino connector and see if you get the frequency displayed.
All the best,
73, John (VK2ETA)
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Re: ND6T AGC implementation for uBIT-X
toggle quoted message
Show quoted text
Gilles,
The total price for 2 kits sent to France is $18.30 ($4.30 for the 2 kits plus $14.00 postage)
73 Kees K5BCQ?
|
Re: ND6T AGC implementation for uBIT-X
Gilles,
The total price for 2 kits sent to France is $18.30 ($4.30 for the 2 kits plus $14.00 postage)
73 Kees K5BCQ?
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Re: W8TEE vft/tft questions
Hi Jack, thanks for answering. I have been watching the debug code you mentioned, and the output has changed since things went south. I added some Serial.print statements of my own.? After watching the debug output for a while, I wanted to know what was going on in SetEncoderDirection:
void SetEncoderDirection() {
? encoderDirection = 0;
? newPosition = rotary.read();
?if (newPosition != oldPosition) {
? ? ?Serial.print("Old: " );
? Serial.println(oldPosition);
? ?Serial.print("New: " );
? Serial.println(newPosition);
?}
? if (newPosition != oldPosition) {
? ? if (newPosition > oldPosition)
? ? ? encoderDirection = 1;
? ? else
? ? ? encoderDirection = -1;
? ? oldPosition = newPosition;
? }
} ...and also here, at the top of your debug block:
#ifdef DEBUG?
?Serial.print("Direction: " );
? Serial.println(encoderDirection);? ? ? ? ?
Serial.print("Examine Fast Tune: Start = ");? ? ? ? // May be useful for setting Fast Tune rate
Serial.print(fasttuneStart);
Serial.print("? ?end = ");
Serial.print(fasttuneEnd);
Serial.print("? diff = ");
Serial.println(fasttuneEnd - fasttuneStart);
#endif? With this in place, I turned the encoder one detent stop, and you see that SetEncoderDirection was called three times.? I kept doing this, slowly, and you can see from the serial monitor output below that even though I am turning the encoder int he same direction, the encoderDirection is variously 1 and -1.? Every 3rd turn the frequency is just not updated at all, but with the vacillating encoderDirection, the freq. goes up 100Hz and down 100Hz.? I thought maybe a bad solder connection was causing a kind of "echo" in the circuit, so I re-flowed the solder to pins 18, 19 and 20.? I have tried a couple of encoders with the debounce caps installed (but who knows, maybe I have a drawer full of bad ones).? I was reading your followup article on encoders and when I got to the end where you suggest always to look for the last thing you think might be wrong, I even changed the connection wires.? Last thing? that I can think of is to swap out the Arduino mini, which I will get to in a day or so (ugh, all those header pins to solder).? If you can suggest anything else, let me know.? Serial output follows: First turn here:
Old: -1
New: 0
Old: 0
New: -1
Old: -1
New: 0
Direction: 1
Examine Fast Tune: Start = 3324? ?end = 11398? diff = 8074
Old: 0
New: -1
Old: -1
New: 0
Old: 0
New: -1
Direction: -1
Examine Fast Tune: Start = 11539? ?end = 31281? diff = 19742
Old: -1
New: 0
Old: 0
New: -1
Old: -1
New: 0
Direction: 1
Examine Fast Tune: Start = 31422? ?end = 40482? diff = 9060
Old: 0
New: -1
Old: -1
New: 0
Old: 0
New: -1
Direction: -1
Examine Fast Tune: Start = 40623? ?end = 48869? diff = 8246
Old: -1
New: 0
|
I did pull the raduino out and booted it standalone. It still showed only the firmware. Would it get locked in factory mode?
Thank you! I thought about that. I tried reverting to the original firmware and it was the same. Was tempted to disconnect the entire encoder but left it as is. Will give it a shot.?
On Wed, May 23, 2018, 2:34 PM John < vk2eta@...> wrote: Hello Sam,
There is a good chance your Raduino is likely working and you have an issue with the encoder.
Since it displays the version at start and nothing more after that it certainly looks like you have the push-button locked or shorted in the down position.
In the factory firmware and the KD8CEC firmware (at least the version you are using), when the push-button is held down at start-up it first waits for the button to be released, then it enters Factory Alignment mode. That's why I suspect the push-button input is held down permanently.
Easy test is to just disconnect the brown wire from the Raduino connector and see if you get the frequency displayed.
All the best,
73, John (VK2ETA)
|
Re: toggle for low output and max output?
#ubitx
Allison, I think VK2ETA's approach is good enough for adjusting the power out by a few dB. He moves where the transmitted signal lies within the 45mhz filter response, taking it down the skirts to attenuate.? The filter is fairly broad, so the frequency? response of our 2khz bandwidth audio is not significantly affected. On receive, the desired signal is put back in the center where it belongs. ? ?? /g/BITX20/message/46235? ?? /g/BITX20/message/46241
It could be that this technique raises the level of some close in undesired products, but not by much if we're only talking a few dB of attenuation.. And I'm not aware of anything undesired that is close enough to matter. If it works, this gives us a no-hardware method of attenuating the transmitted signal. Do you see any issues with this approach? This from Ian:? ? /g/BITX20/message/50144:? ? "2.ATT function has been added to reduce RF gain (Shift 45Mhz IF)" Not clear if that's for transmit or receive. But suggests to me that he has added VK2ETA's trick to his code.
One issue is that the transmitted CW signal never goes through the 45mhz filter. But that could be fixed by having CW unbalance one of the other two mixers, and adjusting the firmware accordingly. Jerry, KE7ER
On Wed, May 23, 2018 at 01:15 pm, ajparent1/KB1GMX wrote:
No matter how you do it it will require hardware with my mods or no.
The easy solution is hard to implement as the places to put it are scarce
and they must be in the TX only path.
The most seemingly likely is two RV1 pots with a relay to select the one you want
and a button on the front panel to activate the relay during transmit.? Problem is
where to put the RF parts so there? aren't dragging wires all over and causing havoc.
The most obvious place is? near the edge next to K1. or as a flying PCB with a
relay, diode, two RV1s that drops into the old RV1 spot and two flying wires for
switching.? Lots of assumptions for space to place things.? Using a tiny relay helps.
Allison
|
Re: toggle for low output and max output?
#ubitx
No, just no.? We are working with a linear or trying to be linear.? Plaing with the voltage to the
finals would be bad.
Allison
|
Thank you! I thought about that. I tried reverting to the original firmware and it was the same. Was tempted to disconnect the entire encoder but left it as is. Will give it a shot.?
On Wed, May 23, 2018, 2:34 PM John < vk2eta@...> wrote: Hello Sam,
There is a good chance your Raduino is likely working and you have an issue with the encoder.
Since it displays the version at start and nothing more after that it certainly looks like you have the push-button locked or shorted in the down position.
In the factory firmware and the KD8CEC firmware (at least the version you are using), when the push-button is held down at start-up it first waits for the button to be released, then it enters Factory Alignment mode. That's why I suspect the push-button input is held down permanently.
Easy test is to just disconnect the brown wire from the Raduino connector and see if you get the frequency displayed.
All the best,
73, John (VK2ETA)
|
Nick VK4PP
K9HZ
Jay - WS4JM