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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
Re: Bitx (40) agc and muting

Derrick Young
 

Yes, more info please.
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.


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
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
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?
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.
Re: uBitxr4 audio distortion fix

 

Another interesting one:






Rahul VU3WJM
Re: uBitxr4 audio distortion fix

 

Diz has one on his site for historical reference. Maybe for topics like these.






73

Rahul VU3WJM
Re: Bitx (40) agc and muting

 

Please share your mods with us!

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 ?
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

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.
Bitx (40) agc and muting

Elmar V?ller
 

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 ?
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.
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

Regards
MVS Sarma
?vu3zmv

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



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

Regards
MVS Sarma
?vu3zmv

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


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
Re: IRF510

 

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
Re: Anyone seen an SSB xmit causing the menu to pop up?

brad martin
 

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

Anyone seen an SSB xmit causing the menu to pop up?

 

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
Re: Running on a Jump Box

 

That's extremely interesting and informative, and completely contrary to what I'm trying to do. I like the answers about using the pot on the board to lower the output power. Excellent. I'll probably do that.

But my initial problem was that, with a particular battery pack, the rig overdrove my tuner, making it fail to tune. Thankfully non-catastrophically, (i.e., it didn't catch fire) but it still wouldn't tune, and indications were that the power was out of range at the top end.

I realize that most users of radios want to MAXIMIZE output power, and then level it across as many bands as possible, so they have lots of output power in all of the bands they want to use. But I don't want to increase the power. I want to control it. The battery's specs list it at 12v @ 5A. So it has plenty of power and shouldn't limit the transmitter. But that's not my issue. The issue is that with that battery supply, there's TOO MUCH OUTPUT. If I run it from a bench supply, it doesn't do this. If I power the bench supply from the battery, it doesn't do this. I'm charging a battery bank I have with a 12vdc output jack, with a limit of 3A, that I'm going to test to see what IT does.

But I don't WANT to maximize RF out. I want to keep it within the limits of my tuner. I will try not setting a limit on the amperage and just try lowering the voltage, and see what that does, if limiting the amperage causes Bad Things.

Am I not being clear as to my goal in this instance? I'm trying to assemble a portable setup to take into the field for battery operation, but everything needs to play nicely with everything else, and the battery I was trying wouldn't play well with the tuner. I'm also testing to see if the problem might have been with the antenna or with the tuner, by testing different antennas and different tuners, to see if the problem actually exists with the BATTERY and not something else. If I can do it with a different battery pack that doesn't overwhelm the rig, PERFECT. But if that's going to cause bad harmonics or spurs or splattery signal, then that's not so perfect. I want to find the actual CAUSE of the difficulty, not just slap a band-aid on it or treat symptoms, but so far the assumptions I keep hearing are that I'm trying to maximize output, which is not the case. If I wanted to maximize output, I'd be building different sorts of radios, not QRP rigs.
Re: Neat power supply!

 

Hello Arv
Plastic cases on power supplies can be sprayed with conducting metal paint on the inside to stop RFI. Just be sure no high voltage parts touch the now metalized surface.
73
--
John VK6JAH
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