Re: RFI from uBitx TX after AGC and other mods installed
John, Don, others,
Yesterday I attached a 78L05 (TO220) directly to the back of
the AGC board that is mounted to the RF gain control on the front panel.
Bypassed all power leads and ran a separate power lead to the 12V regulator that
powers?my uBitx. In other words the AGC board had its own isolated(?) power
source. Stll heard the audio when transmitting.? Beginning to think that
radiated power is being absorbed by the AGC board and then recitifed and then
coupled into the audio system. I also have the pop click board installed and not
sure if this was a problem before it was installed. My AGC board is one I
fabricated using Don's technique of cutting pcb with an x-acto knife.? I
also have a AGC board made on perf board using through hole parts.? May sub
that in and see if there are any changes. I eventually plan on installing the
JackAl mod when it becomes available so this problem should go away for
me?but its beginning to become a challenge to fix.
?
Rick KN4AIE
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Don, I spent part of yesterday applying ferrites to this and that
to little success. I also tried wrapping the 5v line around the twisted pair
coming from the volume pot and that did some good. This morning I was thinking
about fixing a 7805 to the metal base of my case, drilling a hole in the ground
plane and routing a wire through that hole to feed the AGC board. It could be
driven off the 12v relay (K1?). Has anyone else had any
ideas/success? John KC9OJV
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Re: Bitx (40) agc and muting
When you say solder 1n4148 t0 +12v not RX, which one are we talking about?
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Re: Bitx (40) agc and muting
Hello Derrick,
here is more info.
please look at the picture .
hope it is visible.
if you have any question --give me a? shout.
?
?
Gesendet:?Sonntag, 01. Juli 2018 um 13:52 Uhr
Von:?"Derrick Young" <deyoung10@...>
An:[email protected]
Betreff:?Re: [BITX20] Bitx (40) agc and muting
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Re: RFI from uBitx TX after AGC and other mods installed
Don,
I spent part of yesterday applying ferrites to this and that to little success. I also tried wrapping the 5v line around the twisted pair coming from the volume pot and that did some good. This morning I was thinking about fixing a 7805 to the metal base of my case, drilling a hole in the ground plane and routing a wire through that hole to feed the AGC board. It could be driven off the 12v relay (K1?). Has anyone else had any ideas/success?
John
KC9OJV
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Re: Bitx (40) agc and muting
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Re: TX frequency? of uBitx at CWL and CWU mode
#ubitxcw
The firmware is still the original for the ver. 3 Ubitx
Il 01/lug/2018 13:25, "iz oos" < and2oosiz2@...> ha scritto: I usually use a Softrock Ensemble as the receiver for the Ubitx and other rigs. The CW TX in the Ubitx is 700hz off the actual frequency. I believe it was done by purpose although I would have rather preferred it indicated the actual frequency.
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Re: TX frequency? of uBitx at CWL and CWU mode
#ubitxcw
I usually use a Softrock Ensemble as the receiver for the Ubitx and other rigs. The CW TX in the Ubitx is 700hz off the actual frequency. I believe it was done by purpose although I would have rather preferred it indicated the actual frequency.
Il 01/lug/2018 07:43, < jj1epe@...> ha scritto: Hi!
I would like to know whether the behavior of TX frequency of uBitx at CWL and CWU mode I experienced is normal on CECFW v1.08.
For instance,
When there is the CQ station on?7.0100MHz on my ICOM transceiver, ?uBitx at CWL mode shows 7.0085MHz as RX frequency.
Then I transmit CW carrier on ubitx at the exact same RX frequency of uBitx.
CW carrier is observed not at 7.0100MHz but 7.0085MHz on my ICOM transceiver as RX frequency.
When there is the CQ station on?7.0100MHz on my ICOM transceiver, ?uBitx at CWU mode shows 7.0100MHz as RX frequency.
Then I transmit CW carrier on ubitx at the exact same RX frequency of uBitx.
CW carrier is observed not at 7.0115MHz but 7.0100MHz on my ICOM transceiver as RX frequency.
This means that TX frequency is lower 1.5KHz at CWL mode and higher 1.5KHz at CWU mode than actual frequency.
Your comment would be much appreciated.
Akira,
JJ1EPE
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Re: Ubitx receive intermittent
I had a similar problem where w1aw at 10 over would fade out to the point where I could no longer copy them on cw. Worked fine with headphones plugged. Replaced the 2 inch speaker and ok now.
73 John K4FT?
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Re: Ubitx receive intermittent
I fixed the low power issue. It was down to the thick wire I had going from the Neg terminal of the power plug to the rear chassis bolt?? Anyway I removed this and power jumped back up.
The audio is a separate issue. As I said, I believe it is audio and not signal related as when it drops out I still receive signals only much quieter. My board is a later v3 with socketed audio chip. I wonder if I tap off the back of the volume control to a separate amplifier??
Carl.
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Re: uBitxr4 audio distortion fix
Another interesting one:
Rahul VU3WJM
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Re: uBitxr4 audio distortion fix
Diz has one on his site for historical reference. Maybe for topics like these.
73
Rahul VU3WJM
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Re: Bitx (40) agc and muting
Please share your mods with us!
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At 01-07-18, you wrote: Hello,
this famous trx produce annoying chrash during rx/tx switching.
I combined a simple agc curcuit together with muting system to get
rid of any cracks.
Is anyone interested ?
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Re: Ubitx receive intermittent
Carl, gently shake the toroids and see. Tap the relays with the handle end of a small screwdriver and check.
Coil solder has been known to be occasionally bad. Relays also go bad..
Raj
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At 01-07-18, you wrote: Daniel is right, I was tapping off the IF for the RTL dongle....
Unfortunately the radio is now only transmitting .5w too! Today I will test the finals although there is no point replacing them until I can find out why my receive is so intermittent. I do hear stations still, they are just much quieter when it cuts out. So maybe this is an audio amp issue and not a sensitivity fault.
Carl.
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Hello,
this famous trx produce annoying chrash during rx/tx switching.
I combined a simple agc curcuit together with muting system to get
rid of any cracks.
Is anyone interested ?
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Re: Ubitx receive intermittent
Daniel is right, I was tapping off the IF for the RTL dongle....?
Unfortunately the radio is now only transmitting .5w too! Today I will test the finals although there is no point replacing them until I can find out why my receive is so intermittent. I do hear stations still, they are just much quieter when it cuts out. So maybe this is an audio amp issue and not a sensitivity fault.?
Carl.
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Re: Anyone seen an SSB xmit causing the menu to pop up?
check if your supply voltage is dropping on 'hellow'.
- f
On Sun, Jul 1, 2018 at 11:43 AM, Mvs Sarma <mvssarma@...> wrote: Perhaps local radtion due to left over mismatch.
?It might be wiser to shield loose wires to/from audio amp /agc? by shielded wires and shield grounded on one side. Also the power reaching to raduino could be passed thro a diode say 1N5401 and filtered by 100uF parallel 100nF.
All the best
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Re: Anyone seen an SSB xmit causing the menu to pop up?
Perhaps local radtion due to left over mismatch.
?It might be wiser to shield loose wires to/from audio amp /agc? by shielded wires and shield grounded on one side. Also the power reaching to raduino could be passed thro a diode say 1N5401 and filtered by 100uF parallel 100nF.
All the best
On Sun, Jul 1, 2018 at 10:05 AM, brad martin <emclinux@...> wrote: I too have seen this. I have yet to sort mine out and usually for me happens on an antenna and not the dummy load.
Brad
On Sun, Jul 1, 2018 at 12:34 AM Gwen Patton < ardrhi@...> wrote: I was testing into a dummy load and noticed that when I whistled into the mike, or even spoke into it on higher frequencies, would cause the rig to react as if I had pressed the button on the encoder. It showed "Band Select >", and receive stopped. Pressing the encoder twice exited the menu normally. Is this RF getting into the switching transistor the encoder switch trips? How can I prevent this?
Gwen NG3P
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TX frequency? of uBitx at CWL and CWU mode
#ubitxcw
Hi!
I would like to know whether the behavior of TX frequency of uBitx at CWL and CWU mode I experienced is normal on CECFW v1.08.
For instance,
When there is the CQ station on?7.0100MHz on my ICOM transceiver, ?uBitx at CWL mode shows 7.0085MHz as RX frequency.
Then I transmit CW carrier on ubitx at the exact same RX frequency of uBitx.
CW carrier is observed not at 7.0100MHz but 7.0085MHz on my ICOM transceiver as RX frequency.
When there is the CQ station on?7.0100MHz on my ICOM transceiver, ?uBitx at CWU mode shows 7.0100MHz as RX frequency.
Then I transmit CW carrier on ubitx at the exact same RX frequency of uBitx.
CW carrier is observed not at 7.0115MHz but 7.0100MHz on my ICOM transceiver as RX frequency.
This means that TX frequency is lower 1.5KHz at CWL mode and higher 1.5KHz at CWU mode than actual frequency.
Your comment would be much appreciated.
Akira,
JJ1EPE
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I've a tray full of Intersil TO-3 VN66s here dating from about 1980.
Used some in 5 watt qrp amplifier, used to drive it from the Tx low-level stage of my Atlas 210X for QRP.
de miken,? ?zl1bnb
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Re: Anyone seen an SSB xmit causing the menu to pop up?
I too have seen this. I have yet to sort mine out and usually for me happens on an antenna and not the dummy load.
Brad
toggle quoted message
Show quoted text
On Sun, Jul 1, 2018 at 12:34 AM Gwen Patton < ardrhi@...> wrote: I was testing into a dummy load and noticed that when I whistled into the mike, or even spoke into it on higher frequencies, would cause the rig to react as if I had pressed the button on the encoder. It showed "Band Select >", and receive stopped. Pressing the encoder twice exited the menu normally. Is this RF getting into the switching transistor the encoder switch trips? How can I prevent this?
Gwen NG3P
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4Z1NT
Raj vu2zap