re PM for "by" read buy.? typing too fast here...TEF
|
Mr Trager is so unimpressed he is going to package it up and send it back as is .. a single band SSB receiver.? He is fed up with wasting time and money (full set of? 12 crystals was used to select better ones than those supplied) . The schema does not match what he has. He is "over it " and So am I? though there is a solution - use a semi cond bal modulator for Tx? and direct inject into the Tx transistor and add a Mute mosfet. .... too late. TEF
|
Re: Harmonics and Relay Replacement
One note:
DO NOT put relays in sockets as the performance degrades.
Raj
Hi Gene,
There is no final solution.
So far my conclusions... the harmonics floating around the board is the
cause of the spurs.
Changing the L5/7 reduced the spurs but not the cause which is
harmonics.
Changing 3 relays KT1/2/3 reduces the harmonics dramatically specially on
lower bands.
Lower bands 40/80 can be driven higher without crossing the red
line!
Keep the drive/mic level at where you get 10W on 40M and you should be
kosher
without SMD coils on higher bands.
If you over drive the uBitx on higher bands then you will be in the
red!
Some boards behave a bit different, relays are a good simple mod bet for
now.
Raj
At 01-11-18, you wrote:
toggle quoted message
Show quoted text
Sorry to ask but I been offline
for a few weeks and the subject seems to have died out (after reading
past posts).? So is there a final solution for the spurs/harmonics
for the V3 uBitX?
- Axicom replacements (soldered directly to PWB)?
- Axicom replacements with SMD inductors?
- K5BCQ uBITX Relay Switched LPF/BPF board?
I have an unbuilt V3 that I am not sure if I should even
complete.? I want to be legal but do not have a lot of test
equipment so verification will be difficult.
Thanks,
Gene N2IJF
From: [email protected]
<[email protected]> on behalf of Raj vu2zap
<rajendrakumargg@...>
Sent: Thursday, October 25, 2018 12:59 AM
To: [email protected]
Subject: Re: [BITX20] 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:
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
|
Re: Harmonics and Relay Replacement
Hi Gene,
There is no final solution.
So far my conclusions... the harmonics floating around the board is the
cause of the spurs.
Changing the L5/7 reduced the spurs but not the cause which is
harmonics.
Changing 3 relays KT1/2/3 reduces the harmonics dramatically specially on
lower bands.
Lower bands 40/80 can be driven higher without crossing the red
line!
Keep the drive/mic level at where you get 10W on 40M and you should be
kosher
without SMD coils on higher bands.
If you over drive the uBitx on higher bands then you will be in the
red!
Some boards behave a bit different, relays are a good simple mod bet for
now.
Raj
At 01-11-18, you wrote:
toggle quoted message
Show quoted text
Sorry to ask but I been offline
for a few weeks and the subject seems to have died out (after reading
past posts).? So is there a final solution for the spurs/harmonics
for the V3 uBitX?
- Axicom replacements (soldered directly to PWB)?
- Axicom replacements with SMD inductors?
- K5BCQ uBITX Relay Switched LPF/BPF board?
I have an unbuilt V3 that I am not sure if I should even
complete.? I want to be legal but do not have a lot of test
equipment so verification will be difficult.
Thanks,
Gene N2IJF
From: [email protected]
<[email protected]> on behalf of Raj vu2zap
<rajendrakumargg@...>
Sent: Thursday, October 25, 2018 12:59 AM
To: [email protected]
Subject: Re: [BITX20] 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:
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
|
|
|
Congrats on staying with it for so long. Mine has worked well so far and I have mode several improvements to it. But from what I am reading about other folks problems, I must have got lucky. However my unit still defies all attempts at calibration. The instructions are scattered about the Web in various forms. Which is a huge problem for many people, I think so.
I have two v4 boards that are completely deaf. Haven't spent the time yet to do any tracing.
Like you, I've put this on hold indefinitely.
Dave - AI6K
|
Re: uBitX CW Sidetone Volume
Part of the mistery solved...
If you remove R253, you can still hear CW side tone on speaker, because Arduino is using PWM pin for generating audio.
That pin behaves like an antenna, and signal from that pin enters receiver and comes to audio amplifier.
Regarding bumping sound... that sound is heard when CW key is pressed, and released (again, TX is OFF).
Tracing the problem, I found that when you cut the connection between CLK#0 pin from Raduino and main board, that sound doesn't exist any more (while pressing CW key).
Disconnecting the other two CLK signals (CLK#1 and CLK#2) doesn't make any difference.
What is so special about CLK#0 that makes bumping sound to appear?
73
Marko YU2MP
|
Re: Harmonics and Relay Replacement
Sorry to ask but I been offline for a few weeks and the subject seems to have died out (after reading past posts).? So is there a final solution
for the spurs/harmonics for the V3 uBitX?
- Axicom replacements (soldered directly to PWB)?
- Axicom replacements with SMD inductors?
- K5BCQ uBITX Relay Switched LPF/BPF board?
I have an unbuilt V3 that I am not sure if I should even complete.? I want to be legal but do not have a lot of test equipment so verification will be difficult.
Thanks,
Gene N2IJF
toggle quoted message
Show quoted text
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:
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
|
I just ordered a couple of these from Adafruit.
Dave - AI6K
|
Does anyone have a link to a 10K pot I can use for volume control for the uBitx that has power switch. Oddly the one that came with the kit went bad on me. It just freaks out when I touch it and can go from just producing full volume to nothing at all or it just works.
Joe
|
I've got to think about that... I want the person in phone mode to hear my cw. If they're in USB, don't I have to transmit CW-reverse to get into their passband? Ed - aa2mz
|
Thanks, that was it... I think I'd changed its default in the defines but without changing the software version number, the eeprom didn't get updated.
|
Actually it is fairly easy to modify
the Raduino code to put a timer in it to turn off the xmit after
some time.
On 10/31/2018 1:18 PM, Bill Cromwell wrote:
toggle quoted message
Show quoted text
Hi Dave,
Obviously unattended operation is allowed where you live and are
licensed. Some of that is allowed where I live too but the problem
you have outlined is the main reason I don't do unattended
operation. The remote controlled power switch that Kevin suggests
looks like a good solution but you will still have to know when it
needs to be used.
Good luck with it.
73,
Bill? KU8H
On 10/31/2018 02:25 AM, David - CA3DPV wrote:
Hi,
I use an old laptop for FT8 with my uBitx and works perfect (CAT
via
USB). But sometimes my computer hangs (BSOD) and, when the uBitx
is in
Tx, the radio keep transmitting.
I use this computer via TeamViewer, but i don't wanna fry the
power
output when i'm at work and i can't power off the radio when my
PC
hangs. Can i set a TOT to protect my radio? Any firmware with
this feature?
73 from Santiago de Chile,
David, CA3DPV
|
I have two v4 boards that are completely deaf. Haven't spent the time yet to do any tracing.
Like you, I've put this on hold indefinitely.
Dave - AI6K
|
Original thread was "RX Trouble". ? Sort of a rant here...
I am not superstitious but beginning to believe my uBITX (both factory & CEC firmware) is cursed. Have had issues since first power-up, but now I think the problems are fatal.? Have a lot of time & money in it (Axicom relays, trouble shooting, etc.) but think I might call it quits.? Never had problems with my scratch built rigs.? Had a problem with my K2 build, but fixed that when I discovered a copper whisker (under the coating, I took optical micrographs !) shorting a pair of runs on the control board.
However, the uBITX has been a relative nightmare.
Original issues, to name a few:
Not on frequency, low audio, poor RF sensitivity, pinched audio response (narrow - filter issue?),? very narrow tuning for understandable audio, etc.
I fixed the too low for headphones audio with an off board amplifier.? But, the distortion was even worse from the speaker. I found a power/signal driven oscillation in the external amp and fixed that.? Afterward, the volume was OK and the distortion was somewhat lower - but still not great audio.? The other problems remained.
Observation:
There was (I think, maybe) something oscillating on the board. There was a low level (~700) Hz tone on the audio coming from the board.? Found that with a 'scope, but did not find the source. Also, the 12 MHz crystal filter was rather microphonic - With no received signals lightly tapping crystals produced audio output. Normal?? Not normal?
The TX power was inconsistent with measurements by others.? Got 10 +- watts out on higher bands, dropping a bit as frequency increased.? But, for 40M and below, the power dropped to about 1.5 watts while the supply current was much higher (almost by 1 amp). ? Frustrated with the RX problems, decided to look at the TX power issue using 'scope on TPs in the TX amp stages.
-- The following is when the patient died. No brain activity ;) --
CW keyed the TX for testing but I didn't get far before the fatal problem occurred. After a few short dummy load TX sessions, it stopped keying.?? Immediately noticed a display issue.? The top row was all solid fill characters, nothing on the bottom row. Clocks 0, 1, 2 not there.? The 7805 on the Radiuno is supplying 5 v.? This is a bit subjective, but is does not seem to get quite as hot as initially? -? likely not supplying as much current as before?.
Hoping the cause was somehow corrupt firmware, tried reloading. Xloader appeared to connect and tried to upload, but never left the "uploading" mode - Failed to reload firmware.? The display stayed the same - solid top row, empty bottom row.
Tried uBITX Manager to read.? It appeared to connect, but when "Read from uBITX" was attempted, returned this:? "[8:30 PM] Error Receive Length = 0/1027".
OTOH,? uBITX Manager did report success when told to upload the .btx backup file I created earlier (Load from File).? BUT - it again failed the "Read from uBITX" command.? Display never changed.? I get the impression the Arduino died...
Ready to take it outside and shoot it? ;) , but probably will put this project away for now.? A big question is, if a version 5 is released to fix some of the original issues like spur/harmonic levels, do I try again ????????
Better luck to everyone else!
73,? Woody?? KZ4AK
|
?I ordered far too many of the 1K/3W resistors for this project.? I've enough of the passive components plus D1(BAV21) for four additional builds.? ?I've made up four kits consisting of 20 1K/3W, 1 56k, 2 1k (don't have 2k in my box)? resistors, D1 and C1 (50V--ok for QRP, but if you want the 150W version you should replace with a 250-500V as specified).? Drop me a private email if interested.?
John
WI6P
|
Moving the BFO to the other side of the 12mhz crystal filter can make a difference,
as the skirts of the filter are shaped differently.
Also, moving the VFO to the high side (on the Bitx40) or clk1 to the high side (on the uBitx)
can have considerable impact on the birdies that the receiver sees.
Dangerous to make any blanket statements here as to what works best.
The uBitx is quite different from the Bitx40.
The various firmware releases can do different things.
What is best can also depend on what characteristics you are looking for.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Wed, Oct 31, 2018 at 12:20 PM, roger wincer wrote:
CW always uses the USB mode. Until I recently upgraded my uBitx software I had never seen a LSB CW mode. Why that was implemented I don't know. Don't bother about it no-one should ever use it.
?
|
Ty,
make sure semiQSK is ON in the SETTINGS menu.
If the radio is in LSB mode, it will switch to CW automatically as soon as you push the CW key.
(if it's in USB it will switch to CWU).
Press PTT to go back to LSB (or USB).
However when semiQSK is OFF, you need to select CWL (or CWU) manually and press PTT manually for transmitting CW.
73 Allard PE1NWL
|
Ty CW always uses the USB mode. Until I recently upgraded my uBitx software I had never seen a LSB CW mode. Why that was implemented I don't know. Don't bother about it no-one should ever use it.
Roger ZL2RX
|
Hi all,
I've had my bitx40 working for a few weeks and now have implemented the??amunters/bitx40? goodies. Thank you developers and testers!
I was surprised that nothing happened with I pushed the CW key in LSB mode... nothing happened. I expected it to switch to transmit CW on an appropriate CW offset then switch back to LSB receive. Is that not workingon my board or is it not a feature? I didn't find it looking in the code but I thought I ask more experienced operators and code gurus before I dug deeper.
TY, Ed - aa2mz
|
Raj vu2zap
Allard PE1NWL