Re: Harmonics and Relay Replacement
The before relay pic has slightly degraded performance due to the relays
being mounted on
sockets. This add a few mm extra length to the leads to the contact and
increases coupling!
The second is Axicom soldered directly on PCB.
With Axicom my boards are perfect on 40 and 80.
Raj
At 24-10-18, you wrote:
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That's pretty impressive,
Raj.
Jack, W8TEE
On Wednesday, October 24, 2018, 1:06:11 AM EDT, Raj vu2zap
<rajendrakumargg@...> wrote:
Jim,
I did? not get much improvement with Axicom in a socket.. soldering
directly to board made a big difference.
The harmonic rejection on lower bands was amazing!
On one board only 20M is a bit off.
Raj
Example: the first is stock and 2nd is Axicom. The second needs to be
referenced to -1db to compare to
first!
?
?
At 23-10-18, you wrote:
No, I just used the
relays.? I was looking for the simplest approach.? I have
several other projects that were on hold, giving me time to try the relay
swap Mike Doty originally discovered with limited but encouraging
results.?
I've done all I plan on doing regarding the harmonic reduction.? I
shared what I found with the group, got unjustly accused of being a
"phoney" and I now wash my hands of this part of the
project.
Back to improving the available firmware, displays and controller
hardware.?
Jim
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Re: VK4PP uBitx LPF BANK add-on Board
Hi Nick
Happy to test for you, no need to send any parts etc for me.
glenn
vk3pe
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Re: RX trouble Low / BAD Boards?
Woody do you have the version 4 board with the discreet audio amp? If so checkout the archives or Wiki page for a fix/mod for the amplifier. There were some builders that had distorted audio output and to me your recordings sound like that audio distortion. If you can inject a carrier input compare your audio signals at the high side of the volume control and then your output. You can also look at the collector of Q71 which should be the same as the volume control only a larger level.? If you have the IC amplifier then the chip maybe bad.?
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On Oct 24, 2018, at 16:51, Woody < mailme@...> wrote:
Will give that a try, but suspect it is
not the source of the problem.? The speaker out feeds the top of a
500 ohm potentiometer.? Adjusting the drive level to the off board
amp with the pot? (wiper) affects volume available, but doesn't
affect the audio quality.
Attached, FWIW, are two mp3 clips.? "compare 2 noise" is with the
antenna attached, but no signal. First is the ubitx, followed by
the K2. Note: I do have a bit of power line noise.?
"compare 2" is of a 40M QSO.? Ubitx first, then the K2.
--------------
Tried the off board amp, tapping into earlier audio stages.? Input
level so low, could not hear the output
-----------------
Still scratching my head!?? Compared the ubitx to my Elecraft K2
by switching the antenna to each on a S5 (on K2) signal.? The RF
sensitivity is not as good as the K2 and (still) shows some
distortion.
WELL, WELL, WELL...
Pulled out the o'scope and made some measurements.? I think I have
a bad ubitx.? I can only get a measurable signal from CLK 0 - TP18
reads 1.3 v PP.?? TP15 (CLK 1) and TP12 (CLK 2) are below what I
can measure with a 5mv scale with 10x probe.? It is a wonder I
hear anything!!!? Also may explain the super low audio when I do
hear something.? Probably why the BFO adjustment is really weird
too.
Here is a list of the TPs I have checked (no antenna):
TP 1? -? Zero (zero = below readability)
TP 12 -? Zero? (CLK 2) No signal either side of R100 either.
TP 14 -? Zero
TP 15 - Zero? No signal either side of of R106 either.
TP 18 - (CLK 0)? 1.3 v PP
Note that "Zero" may have some signal, but below my scope's
measurement capability.
Measured the Raduino directly where it plugs into the main board.
Confirms what I saw above.? Pin 19 (CLK 0), lots of signal.? Pin
16 (CLK 1), no signal.? Pin 13 (CLK 2) no signal.
Looks like I need to contact HFsignals.
Woody, KZ4AK
On 10/24/2018 16:27, Richie Chambless wrote:
Woody?
I just listened to your sound clips and I heard distortion that¡¯s
usually produced when a source signal overdrives the next stage.
Where are you connecting your outboard amp? I would think that you
would get distortion if you connected it to the speaker out (8 ohm
impedance). I would tap the audio at the volume pot (top lug) if
you haven¡¯t already.?
<compare 2 noise.mp3>
<compare 2.mp3>
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Re: VK4PP uBitx LPF BANK add-on Board
Thanks Glenn,
Will do, ill try get it done this weekend... Do you want a few for yourself?
Many Thanks.
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Re: VK4PP uBitx LPF BANK add-on Board
Nick, I have been away on a holiday......
If you would like to send just the assembled new LPF board to me< i will check it over for you with SA etc.
Glenn
vk3pe
|
Oh okay, sorry for the typos. But I guess I didn¡¯t understand you. Set the bias so the current is less then 12mA, got it. Not find a part that don¡¯t exceed 20mA which is what I thought you meant in your notes. I didn¡¯t understand that.?
Thanks
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On Oct 24, 2018, at 3:17 PM, ajparent1/KB1GMX < kb1gmx@...> wrote: Joe, Yes, a cap C81.
? please you please clarify and if that is the spec for the BFR106 will that part in the data sheet work. The only thing I see about current in the ma is.?
Collector current IC 210 mA Base current IB 21ma
What are you saying...??? Are you asking based on some _mumble_ the part is wrong?
? Set the bias so that the current is less than 12mA.? ?You can measure that current at the emitter by measuring the
voltage across the resistor R82.? The resistor to change is R81.
Allison
|
Re: RX trouble Low / BAD Boards?
Will give that a try, but suspect it is
not the source of the problem.? The speaker out feeds the top of a
500 ohm potentiometer.? Adjusting the drive level to the off board
amp with the pot? (wiper) affects volume available, but doesn't
affect the audio quality.
Attached, FWIW, are two mp3 clips.? "compare 2 noise" is with the
antenna attached, but no signal. First is the ubitx, followed by
the K2. Note: I do have a bit of power line noise.?
"compare 2" is of a 40M QSO.? Ubitx first, then the K2.
--------------
Tried the off board amp, tapping into earlier audio stages.? Input
level so low, could not hear the output
-----------------
Still scratching my head!?? Compared the ubitx to my Elecraft K2
by switching the antenna to each on a S5 (on K2) signal.? The RF
sensitivity is not as good as the K2 and (still) shows some
distortion.
WELL, WELL, WELL...
Pulled out the o'scope and made some measurements.? I think I have
a bad ubitx.? I can only get a measurable signal from CLK 0 - TP18
reads 1.3 v PP.?? TP15 (CLK 1) and TP12 (CLK 2) are below what I
can measure with a 5mv scale with 10x probe.? It is a wonder I
hear anything!!!? Also may explain the super low audio when I do
hear something.? Probably why the BFO adjustment is really weird
too.
Here is a list of the TPs I have checked (no antenna):
TP 1? -? Zero (zero = below readability)
TP 12 -? Zero? (CLK 2) No signal either side of R100 either.
TP 14 -? Zero
TP 15 - Zero? No signal either side of of R106 either.
TP 18 - (CLK 0)? 1.3 v PP
Note that "Zero" may have some signal, but below my scope's
measurement capability.
Measured the Raduino directly where it plugs into the main board.
Confirms what I saw above.? Pin 19 (CLK 0), lots of signal.? Pin
16 (CLK 1), no signal.? Pin 13 (CLK 2) no signal.
Looks like I need to contact HFsignals.
Woody, KZ4AK
On 10/24/2018 16:27, Richie Chambless wrote:
Woody?
I just listened to your sound clips and I heard distortion that¡¯s
usually produced when a source signal overdrives the next stage.
Where are you connecting your outboard amp? I would think that you
would get distortion if you connected it to the speaker out (8 ohm
impedance). I would tap the audio at the volume pot (top lug) if
you haven¡¯t already.?
_._,_._,_
--?
|
Thanks for ?your reply Gordon I have not upgraded my software (ver 4.3) yet. The instruction I received originally for changing values for calibration and BFO were some how out of date. They would not work with my software.?
The procedure for saving changes appears to me to very often not work. After making changes I exit SeTTINGS then exit MENU then switch off the rig and wait ten secs. Sometimes it works sometimes not....... 73
On Thu, 25 Oct 2018 at 08:14, Gordon Gibby < ggibby@...> wrote:
I just rewrite the software to put in numbers that work
On Oct 24, 2018, at 14:53, roger wincer < zedl2rx@...> wrote:
Thanks Gordon...
I have been working on this for about 5 weeks.My project was to replace the Tx and Rx of an old Kenwood TS120S with the uBitx. This I have done and have improved the receiver by adding audio filters. It now runs 100watts and I am quite pleased
with it
But this calibration thing has got the better of me. I have read so many conflicting instructions abt how to do it. I notice last night that my BFO changes are not being saved! This kind of event drives me nuts.
How do you save your changes?
73
Roger
On Thu, 25 Oct 2018 12:28 am Gordon Gibby < ggibby@...> wrote:
I may have put on GitHub ?the little software to upload to the uBitx ?to get it to go to a certain freq.? The idea was to get it to go to the frequency of the Crystal itself: so phase locked loop was 1 to 1
Then whatever frequency you measured tells you how far off the crystal is , mine were about 3 kHz off; if you¡¯ve already adjusted your frequencies correctly you may not need this
Then just use a waterfall looking at White Noise to set the BFo frequency to get the right audio pass band. If you change it but too much there¡¯s a chance you¡¯ll flip sidebands, ?but I bet most people won¡¯t. ?
On Oct 24, 2018, at 03:28, roger wincer < zedl2rx@...> wrote:
Thanks Gordon...much appreciated.
?
73
Roger
?
Sent from for Windows 10
?
?
It¡¯s been a while, but I think I calibrated the main oscillator by commanding it to 10 MHz and then measuring the frequency with a small piece of wire near it going into an Icom 718.? Then put the proper constant into the software.?
From there, use any digital software that lets you see the power across the ?audio spectrum and adjust while listening to galactic White Noise, so it is in the proper audio passband. ? If my memory is correct, my passbands were a bit narrow.
? You could use free FLDIGI or probably any of a zillion other products.
?
On Oct 24, 2018, at 01:28, roger wincer <zedl2rx@...> wrote:
In the history of the uBitx has anyone ever calibrated the readout and set the BFO correctly. If so please advise how it was done and saved. I am begining to think its impossible.
<18392439DBD74B66BC7BFF85F28C66E3.png>
<EAA5FB27B49C413D89A3C6F2675EFD32.png>
|
555 timer to sweep the BFO crystal up and down while observing filter output on
a dual-channel analog oscilloscope.? 555 sweep recovery provided sync for the
scope.?
_._
So ...20 or so years ago I decided to build a xtal filter for the "ZOI" spect-an ...First built a "wobbulator" with one of the crystal stash ..(had to add series inductance to the crystal to get it to tune lower ...Ramp generator to sweep it ...tested the xtals for "nearly matching" frequency (Fs/Fp) ..Variable caps to "tune" it ...Time or money ...choices
Jim
On Wednesday, October 24, 2018, 8:55:38 AM PDT, Wayne Leake < wayneleake@...> wrote:
?I have been thinking about building an 8 Xtal version of the filter myself.
many of us have limited test gear, so have to make do with what we have or can cobble up. ?YMMV ?Wayne WA2YNE ?Imperial TX.
|
Joe, Yes, a cap C81.
? please you please clarify and if that is the spec for the BFR106 will that part in the data sheet work. The only thing I see about current in the ma is.?
Collector current IC 210 mA Base current IB 21ma
What are you saying...??? Are you asking based on some _mumble_ the part is wrong?
? Set the bias so that the current is less than 12mA.? ?You can measure that current at the emitter by measuring the
voltage across the resistor R82.? The resistor to change is R81.
Allison
|
I just rewrite the software to put in numbers that work
On Oct 24, 2018, at 14:53, roger wincer < zedl2rx@...> wrote:
toggle quoted message
Show quoted text
Thanks Gordon...
I have been working on this for about 5 weeks.My project was to replace the Tx and Rx of an old Kenwood TS120S with the uBitx. This I have done and have improved the receiver by adding audio filters. It now runs 100watts and I am quite pleased
with it
But this calibration thing has got the better of me. I have read so many conflicting instructions abt how to do it. I notice last night that my BFO changes are not being saved! This kind of event drives me nuts.
How do you save your changes?
73
Roger
On Thu, 25 Oct 2018 12:28 am Gordon Gibby < ggibby@...> wrote:
I may have put on GitHub ?the little software to upload to the uBitx ?to get it to go to a certain freq.? The idea was to get it to go to the frequency of the Crystal itself: so phase locked loop was 1 to 1
Then whatever frequency you measured tells you how far off the crystal is , mine were about 3 kHz off; if you¡¯ve already adjusted your frequencies correctly you may not need this
Then just use a waterfall looking at White Noise to set the BFo frequency to get the right audio pass band. If you change it but too much there¡¯s a chance you¡¯ll flip sidebands, ?but I bet most people won¡¯t. ?
On Oct 24, 2018, at 03:28, roger wincer < zedl2rx@...> wrote:
Thanks Gordon...much appreciated.
?
73
Roger
?
Sent from for Windows 10
?
?
It¡¯s been a while, but I think I calibrated the main oscillator by commanding it to 10 MHz and then measuring the frequency with a small piece of wire near it going into an Icom 718.? Then put the proper constant into the software.?
From there, use any digital software that lets you see the power across the ?audio spectrum and adjust while listening to galactic White Noise, so it is in the proper audio passband. ? If my memory is correct, my passbands were a bit narrow.
? You could use free FLDIGI or probably any of a zillion other products.
?
On Oct 24, 2018, at 01:28, roger wincer <zedl2rx@...> wrote:
In the history of the uBitx has anyone ever calibrated the readout and set the BFO correctly. If so please advise how it was done and saved. I am begining to think its impossible.
<18392439DBD74B66BC7BFF85F28C66E3.png>
<EAA5FB27B49C413D89A3C6F2675EFD32.png>
|
Thanks Gordon... I have been working on this for about 5 weeks.My project was to replace the Tx and Rx of an old Kenwood TS120S with the uBitx. This I have done and have improved the receiver by adding audio filters. It now runs 100watts and I am quite pleased with it But this calibration thing has got the better of me. I have read so many conflicting instructions abt how to do it. I notice last night that my BFO changes are not being saved! This kind of event drives me nuts. How do you save your changes? 73 Roger
On Thu, 25 Oct 2018 12:28 am Gordon Gibby < ggibby@...> wrote:
I may have put on GitHub ?the little software to upload to the uBitx ?to get it to go to a certain freq.? The idea was to get it to go to the frequency of the Crystal itself: so phase locked loop was 1 to 1
Then whatever frequency you measured tells you how far off the crystal is , mine were about 3 kHz off; if you¡¯ve already adjusted your frequencies correctly you may not need this
Then just use a waterfall looking at White Noise to set the BFo frequency to get the right audio pass band. If you change it but too much there¡¯s a chance you¡¯ll flip sidebands, ?but I bet most people won¡¯t. ?
On Oct 24, 2018, at 03:28, roger wincer < zedl2rx@...> wrote:
Thanks Gordon...much appreciated.
?
73
Roger
?
Sent from for Windows 10
?
?
It¡¯s been a while, but I think I calibrated the main oscillator by commanding it to 10 MHz and then measuring the frequency with a small piece of wire near it going into an Icom 718.? Then put the proper constant into the software.?
From there, use any digital software that lets you see the power across the ?audio spectrum and adjust while listening to galactic White Noise, so it is in the proper audio passband. ? If my memory is correct, my passbands were a bit narrow.
? You could use free FLDIGI or probably any of a zillion other products.
?
On Oct 24, 2018, at 01:28, roger wincer <zedl2rx@...> wrote:
In the history of the uBitx has anyone ever calibrated the readout and set the BFO correctly. If so please advise how it was done and saved. I am begining to think its impossible.
<18392439DBD74B66BC7BFF85F28C66E3.png>
<EAA5FB27B49C413D89A3C6F2675EFD32.png>
|
Re: VK4PP uBitx LPF BANK add-on Board
Hello Nick
I'm interested by sweeperino and a Specan from long time. I also considered building these modules.
I will wait for the result of your experiments because I am not a skilled technician.
73 QRO F1BFU /FR
I am building a sweeperino and then a specan. this will hopefully help test these boards more...
73 Nick VK4PP.
|
So ...20 or so years ago I decided to build a xtal filter for the "ZOI" spect-an ...First built a "wobbulator" with one of the crystal stash ..(had to add series inductance to the crystal to get it to tune lower ...Ramp generator to sweep it ...tested the xtals for "nearly matching" frequency (Fs/Fp) ..Variable caps to "tune" it ...Time or money ...choices
Jim
On Wednesday, October 24, 2018, 8:55:38 AM PDT, Wayne Leake <wayneleake@...> wrote:
?I have been thinking about building an 8 Xtal version of the filter myself.
many of us have limited test gear, so have to make do with what we have or can cobble up. ?YMMV ?Wayne WA2YNE ?Imperial TX.
|
Wayne WA2YNE
If you use individual variable capacitors (or individually controllable varicaps) you can
fine-tune your filter performance.? While watching filter shape factor on a swept frequency
layout you can carefully adjust each section for best shape factor and lowest insertion
loss.? If you add some way to vary the input and output impedance matching you can also
fine-tune ripple in the passband, and make small improvements in shape factor (steeper
skirts and minimize pop-ups outside the passband).? The procedure and results do take
a bit of playing but may be worth the effort for critical performance needs.?
If building a filter for a specific receiver, transmitter, or transceiver you may want to include
the input and output amplifiers in your test jig.? This lets you match things for the circuit that
it will be working in. ?
Methods shown in QEX and other publications will get you in the ballpark, but it is usually?
possible to improve on that with a well thought out test jig and some time tinkering with
components.? While not useful for mass-production of filters this tinkering can provide
the-best-filter-you-can-get with the components you have on hand.?
Arv _._
?I have been thinking about building an 8 Xtal version of the filter myself.
?I had not thought about using variable caps, nor varactor diodes. ?I am building a bare board BITX20, and I can build the Xtal filter on a sub board, which can make it easier to install, especially if I use? 2 and/or 3 pin connectors with shortest possible wires to connect. ?I could choose between 10Mhz and 12Mhz. ?Even maybe a higher frequency like 25 or 26Mhz. ?I don't have access to a spectrum analyzer, though I thought about building one of sorts. ?I can readily check the actual frequencies of the Xtals, as I have 3 frequency counters. ?At least I think I have 3 that will work. ?One in the MFJ antenna analyzer, an older LED Heathkit, and a much more recent counter that will count up in the Ghz ranges. It also has a crystal osc./tester, but the socket is klutzy, and you need to hold? the Xtal in place. ?Assembling an Xtal tester that will work well enough for what I need. many of us have limited test gear, so have to make do with what we have or can cobble up. ?YMMV ?Wayne WA2YNE ?Imperial TX.
|
Woody?
I just listened to your sound clips and I heard distortion that¡¯s usually produced when a source signal overdrives the next stage. Where are you connecting your outboard amp? I would think that you would get distortion if you connected it to the speaker out (8 ohm impedance). I would tap the audio at the volume pot (top lug) if you haven¡¯t already.?
|
?I have been thinking about building an 8 Xtal version of the filter myself.
?I had not thought about using variable caps, nor varactor diodes. ?I am building a bare board BITX20, and I can build the Xtal filter on a sub board, which can make it easier to install, especially if I use? 2 and/or 3 pin connectors with shortest possible wires to connect. ?I could choose between 10Mhz and 12Mhz. ?Even maybe a higher frequency like 25 or 26Mhz. ?I don't have access to a spectrum analyzer, though I thought about building one of sorts. ?I can readily check the actual frequencies of the Xtals, as I have 3 frequency counters. ?At least I think I have 3 that will work. ?One in the MFJ antenna analyzer, an older LED Heathkit, and a much more recent counter that will count up in the Ghz ranges. It also has a crystal osc./tester, but the socket is klutzy, and you need to hold? the Xtal in place. ?Assembling an Xtal tester that will work well enough for what I need. many of us have limited test gear, so have to make do with what we have or can cobble up. ?YMMV ?Wayne WA2YNE ?Imperial TX.
|
Thanks for all the suggestions!?? I plan to give some a try.? I agree that setting alignment is not trivial.? I also agree that CW seems OK.? Tuning around, the BW seems near what I would expect for SSB filtering and distortion is minimal.? My scratch built SSB rigs were really easy by comparison.
The "pinched" SSB audio is an annoyance, but not a show-stopper. The need to be dead-on frequency for decent SSB is more of an issue.? When listening to QSOs, the symptom is apparent - If tuned for good audio on station 1, and station 2 is just a bit off freq, it is hard to understand.? ...It is that critical.? Possibly a result of the filter's narrow bandwith / center position?? More tweaking may help.? I have a broadband RF noise generator (homebrew, of course) and PC audio spectrum analyzer used to align my Elecraft K2.? May give that a try.?? The BFO adjustment is a pain.? There is some, but not much change with lots of encoder spinning.? Wonder if I will wear out the encoder before it is done. ;)
Best I can tell, my TX audio is OK, but hard to tell exactly when listening to myself.? No on-air tests yet.
An AGC is also on my agenda, have Axicom relays and replacement inductors, but want to get the board functioning as well as possible before jumping in with modifications.
Have archived the replies and the testing continues...
73,
Woody, KZ4AK
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Re: One Month With The uBitx
Hi Curt, ???????????? I started off buildiong in 1985 from basic kits produced here in te uk by CM HOWES...At the time i hankered after a radio produiced over here which was 9 bands all mode called the OMEGA ( PICTURE ON MY QRZ PAGE).but that was the cost of 2 months mortgage so never got done,30 years later in quick succession 2 appeared on ebay which i bought as spares or repairs i robbed one to get the other running? plus 2 years after the omega the author produced a 6 band 15 watt cw transceiver and again at the time couldnt afford it but shortly after i got, my 2 omegas the micron came up on ebay as spares or repairs and i bought that to date both the olmega and micron are running reliably and have given me an immence amount of pleasure..these are now having a rest as the ubitx is now my main comercial radios at all in the shack save a 2 mtr fm radio.regards Dave.G0AYD. PSThe omega took 5 weeks to rejuvanate..rewire and resolder 1300 dry joints!!!!!.
the micron took 2 hours a 5 and 8 volt regulator amd an lm 380 ic.
On Tue, 23 Oct 2018 at 16:34, Curt M. < Kc3hjp@...> wrote: Hi Dave, after using my uBitx for one day I did install the CEC firmware which I forgot to mention.? That makes it's really easy to use and experiment with being that you can backup and restore your settings.
As far as kits go I started out with a Bitx40 in which right out of the gate I received a non functional board.? I was never able to figure out what was wrong with it.? The replacement board came, I didn't change a thing with my wiring and just connected the board up and it's been fully functional from the get go.
I'm hoping that these kits will spin off some kids that are getting their feet wet in electronics with Raspberry Pi's and maybe we'll get a new crop of hams.
|
Re: PA Alignment of uBITX
#ubitx
Hi John, I believe that my v3 was a little lower than specified also. I did as you have done and just added 100mA additional from each pot and I closed up the case. ?I've made contacts all over the place with mine. ?
Have fun!
Curt M
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Raj vu2zap
Skip Davis
Nick VK4PP