¿ªÔÆÌåÓý

Date

Re: ?BITX ... AGC or AVC? an interesting article by Curt WB8YYY ... maAgain,e that's the solution to my troubles ! #ubitx #bitx40 #bitx20 #ubitxv6 #v6

 

Right Arv ... Software is the way to go. Otherwise someone is being amazed by flashing lights and bird whistles. This is just one opinion, however.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 3:12:56 PM EDT, Arv Evans <arvid.evans@...> wrote:


Bob and Jack

Seems that if you are using that circuit and an ADC input in place of an analog?
meter, you could use software to convert the ADC readings into VU meter,?
S-meter, or anything else.? Might be a way to show Peak readings versus?
Average, and even to calculate receiver input in Microvolts.

Arv
_._


On Wed, Oct 28, 2020 at 11:26 AM Bob Lunsford via <nocrud222=[email protected]> wrote:
The signal off the volume control can be used as a signal source for either S-meter purposes OR a way to control an AGC circuit by causing attenuation for signals above a pre-set level. However, I learned with my G90 that there are times when the AGC should be shut off to provide maximum signal gain.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 12:56:25 PM EDT, Jack, W8TEE via <jjpurdum=[email protected]> wrote:


Again, I'm not an EE type, but if the metering is done off the volume control, is it really an SWR meter or a VU meter??

Jack, W8TEE

On Wednesday, October 28, 2020, 12:49:45 PM EDT, Bob Lunsford via <nocrud222=[email protected]> wrote:


This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.

Bob ¡ª KKR

Inline image


On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris <lorisbollina@...> wrote:


On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR

--
Jack, W8TEE


Re: Duh-oo

 

Everything is relative. One's S-meter reading depends on the receiver AND the antenna. One too many variables. A Volume Unit reading is based on voltage across a standard resister value. The VU reading may be more accurate but still has too many variables.

Personally, I do not need an S-meter and unless someone asks me, I do not give a Signal Strength report. It means little to me when we are talking about readability.

I can come up with a circuit that may warm someone's heart but my V6 does not need an S-meter. HOWEVER, the same circuit can be an operator for the AGC circuit. Old time operators used to pull the "cans" off the ears and put them over the temple to either adjust the audio level or keep excessive volume from waking them up. Been there, done that...

Bob ¡ª KK5R



On Wednesday, October 28, 2020, 2:26:54 PM EDT, Jack, W8TEE via groups.io <jjpurdum@...> wrote:


My bad, it should have read:

Again, I'm not an EE type, but if the metering is done off the volume control, is it really an? S meter or a VU meter??

Jack, W8TEE


On Wednesday, October 28, 2020, 1:26:27 PM EDT, Bob Lunsford via groups.io <nocrud222@...> wrote:


The signal off the volume control can be used as a signal source for either S-meter purposes OR a way to control an AGC circuit by causing attenuation for signals above a pre-set level. However, I learned with my G90 that there are times when the AGC should be shut off to provide maximum signal gain.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 12:56:25 PM EDT, Jack, W8TEE via groups.io <jjpurdum@...> wrote:


Again, I'm not an EE type, but if the metering is done off the volume control, is it really an SWR meter or a VU meter??

Jack, W8TEE

On Wednesday, October 28, 2020, 12:49:45 PM EDT, Bob Lunsford via groups.io <nocrud222@...> wrote:


This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.

Bob ¡ª KKR

Inline image


On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris <lorisbollina@...> wrote:


On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR

--
Jack, W8TEE

--
Jack, W8TEE


Re: ?BITX ... AGC or AVC? an interesting article by Curt WB8YYY ... maAgain,e that's the solution to my troubles ! #ubitx #bitx40 #bitx20 #ubitxv6 #v6

Jack, W8TEE
 

Agree.

Jack, W8TEE

On Wednesday, October 28, 2020, 3:12:56 PM EDT, Arv Evans <arvid.evans@...> wrote:


Bob and Jack

Seems that if you are using that circuit and an ADC input in place of an analog?
meter, you could use software to convert the ADC readings into VU meter,?
S-meter, or anything else.? Might be a way to show Peak readings versus?
Average, and even to calculate receiver input in Microvolts.

Arv
_._


On Wed, Oct 28, 2020 at 11:26 AM Bob Lunsford via <nocrud222=[email protected]> wrote:
The signal off the volume control can be used as a signal source for either S-meter purposes OR a way to control an AGC circuit by causing attenuation for signals above a pre-set level. However, I learned with my G90 that there are times when the AGC should be shut off to provide maximum signal gain.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 12:56:25 PM EDT, Jack, W8TEE via <jjpurdum=[email protected]> wrote:


Again, I'm not an EE type, but if the metering is done off the volume control, is it really an SWR meter or a VU meter??

Jack, W8TEE

On Wednesday, October 28, 2020, 12:49:45 PM EDT, Bob Lunsford via <nocrud222=[email protected]> wrote:


This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.

Bob ¡ª KKR

Inline image


On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris <lorisbollina@...> wrote:


On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR

--
Jack, W8TEE


--
Jack, W8TEE


Re: ?BITX ... AGC or AVC? an interesting article by Curt WB8YYY ... maAgain,e that's the solution to my troubles ! #ubitx #bitx40 #bitx20 #ubitxv6 #v6

 

Bob and Jack

Seems that if you are using that circuit and an ADC input in place of an analog?
meter, you could use software to convert the ADC readings into VU meter,?
S-meter, or anything else.? Might be a way to show Peak readings versus?
Average, and even to calculate receiver input in Microvolts.

Arv
_._


On Wed, Oct 28, 2020 at 11:26 AM Bob Lunsford via <nocrud222=[email protected]> wrote:
The signal off the volume control can be used as a signal source for either S-meter purposes OR a way to control an AGC circuit by causing attenuation for signals above a pre-set level. However, I learned with my G90 that there are times when the AGC should be shut off to provide maximum signal gain.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 12:56:25 PM EDT, Jack, W8TEE via <jjpurdum=[email protected]> wrote:


Again, I'm not an EE type, but if the metering is done off the volume control, is it really an SWR meter or a VU meter??

Jack, W8TEE

On Wednesday, October 28, 2020, 12:49:45 PM EDT, Bob Lunsford via <nocrud222=[email protected]> wrote:


This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.

Bob ¡ª KKR

Inline image


On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris <lorisbollina@...> wrote:


On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR

--
Jack, W8TEE


Duh-oo

Jack, W8TEE
 

My bad, it should have read:

Again, I'm not an EE type, but if the metering is done off the volume control, is it really an? S meter or a VU meter??

Jack, W8TEE


On Wednesday, October 28, 2020, 1:26:27 PM EDT, Bob Lunsford via groups.io <nocrud222@...> wrote:


The signal off the volume control can be used as a signal source for either S-meter purposes OR a way to control an AGC circuit by causing attenuation for signals above a pre-set level. However, I learned with my G90 that there are times when the AGC should be shut off to provide maximum signal gain.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 12:56:25 PM EDT, Jack, W8TEE via groups.io <jjpurdum@...> wrote:


Again, I'm not an EE type, but if the metering is done off the volume control, is it really an SWR meter or a VU meter??

Jack, W8TEE

On Wednesday, October 28, 2020, 12:49:45 PM EDT, Bob Lunsford via groups.io <nocrud222@...> wrote:


This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.

Bob ¡ª KKR

Inline image


On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris <lorisbollina@...> wrote:


On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR

--
Jack, W8TEE

--
Jack, W8TEE


Re: No output power on #v3

 

The only "pop and smoke" experience I ever had was when I bought a Swan 350 at a hamfest that was a "Sure, it's working!" radio so when I plugged it in at home, it sounded like a shotgun shell going off. The power supply caps had to be replaced.

Nothing like a PnS experience to add to one's bank of experience.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 1:31:29 PM EDT, _Dave_ AD0B <davesters@...> wrote:


Hi Evan,
The comment was not directed at you but as information for the poster of the statement.?

I don't think that I can a recall a single instance where a pop and smoke left my equipment working.
--
73
Dave


Re: No output power on #v3

 

Dave,
I would agree that there are very few times that the combination of pop and smoke did not indicate something failed.? The only time I can think of that it was not a part failure was when a whisker from a stranded wire shorted and poped/fried.? That wire had to be repaired, however, it did not take down any of the components, nor traces on the board.? It acted as a fuse.

Kit had been working on a wiring ribbon cable, so the possibility of the same thing happening is good.? I would strongly agree with you that the rig needs to be looked over very carefully for any signs of damage, and try to find the location of the smoke.? There is at least the potential for carbon or metal splatter that can cause other issues.

Thank you for the feedback.
73
Evan
AC9TU


Re: No output power on #v3

 

Hi Evan,
The comment was not directed at you but as information for the poster of the statement.?

I don't think that I can a recall a single instance where a pop and smoke left my equipment working.
--
73
Dave


Re: ?BITX ... AGC or AVC? an interesting article by Curt WB8YYY ... maAgain,e that's the solution to my troubles ! #ubitx #bitx40 #bitx20 #ubitxv6 #v6

 

The signal off the volume control can be used as a signal source for either S-meter purposes OR a way to control an AGC circuit by causing attenuation for signals above a pre-set level. However, I learned with my G90 that there are times when the AGC should be shut off to provide maximum signal gain.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 12:56:25 PM EDT, Jack, W8TEE via groups.io <jjpurdum@...> wrote:


Again, I'm not an EE type, but if the metering is done off the volume control, is it really an SWR meter or a VU meter??

Jack, W8TEE

On Wednesday, October 28, 2020, 12:49:45 PM EDT, Bob Lunsford via groups.io <nocrud222@...> wrote:


This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.

Bob ¡ª KKR

Inline image


On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris <lorisbollina@...> wrote:


On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR

--
Jack, W8TEE


Re: No output power on #v3

 

Considering that the radio's boards are pretested and aligned, causing smoke and pops would have to be an accident or intentional. I got my new V6 yesterday at the Post Office (DHL sent the radio from the Cincinnati hub by USPS to my Post Offic) and within an hour of opening the box, it was a working radio on my bench. No Problem. No smoke, no pops. Nor did I expect anything like this when turning on the power. It's a simple plug-n-chug operation to assemble ... as long as the assembler uses a metric scale to make sure to use the proper (short) screws to mount the complete case.

I assembled nearly all the ham radio Heath kits and only had one diode with the cathode band on the wrong end and a screw with no threads. With uBITX, I don't even expect to find this.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 9:57:19 AM EDT, _Dave_ AD0B <davesters@...> wrote:


Pops and smoking are a normal part of uBITX startups..












NOT!!!!!!!!!

--
73
Dave


Re: Simple UBITX Test Set

 

When playing my new V6 on a local AM broadcast station and listening to the same station on my main radio, there is a way to know when the two signals are on the same frequency because you can hear the frequency difference between the two audio signals. It is a signal that can be nulled and if both are in the USB or LSB mode, you can read the signal discrepancy frequency by tuning the main radio up or down from the zero beat signal and reading the frequencies on the main rig's display. Then you have to wonder if the main rig's dial is off frequency OR if the broadcast station is not squarely on frequency. Doing this with other stations will give some confidence in the broadcast station's frequency accuracy since they are beholden to the FCC to be on the correct frequency. This may open up a nest of snakes when dealing with some podunk station, however, but the chance of it being inaccurate is slim.

Something to play with, anyway.

Bob ¡ª KK5R

On Wednesday, October 28, 2020, 7:54:34 AM EDT, Vic WA4THR via groups.io <vhklein@...> wrote:


Regarding trying to calibrate with WWV, it actually is easier if you have a second AM receiver when WWV is sending tones. You can then match the tone frequency between the uBitX and the AM receiver much easier than when zero beating as you can do that within a few cycles as opposed to losing the low frequency notes perhaps 100's of cycles before zero beat. Note, to be accurate the 2nd receiver needs to be AM, which eliminates that receiver's error which could be added to the perceived tone frequency if using SSB. That is the technique I used on mine and it is dead on frequency.

=Vic=


Re: ?BITX ... AGC or AVC? an interesting article by Curt WB8YYY ... maAgain,e that's the solution to my troubles ! #ubitx #bitx40 #bitx20 #ubitxv6 #v6

Jack, W8TEE
 

Again, I'm not an EE type, but if the metering is done off the volume control, is it really an SWR meter or a VU meter??

Jack, W8TEE

On Wednesday, October 28, 2020, 12:49:45 PM EDT, Bob Lunsford via groups.io <nocrud222@...> wrote:


This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.

Bob ¡ª KKR

Inline image


On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris <lorisbollina@...> wrote:


On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR

--
Jack, W8TEE


Re: ?BITX ... AGC or AVC? an interesting article by Curt WB8YYY ... maybe that's the solution to my troubles ! #ubitx #bitx40 #bitx20 #ubitxv6 #v6

 

This again is offered to show an S-meter circuit borrowed from the transceiver circuit being sold from Indonesia. It is apparently attachable to the volume control and since it's in the receive system, it does not affect the transmit system. It can be "rubbered" here and there since the component values may be the best for this considering that they are what is available to the builders in Indonesia, the FET and transistor can work equally well when using substitutes. Attaching to the high end of the uBITX's volume control and making the 47K variable in the circuit below a set resistor for calibration purposes results in making this a usable circuit. The meter, of course, can be substituted with an LED barcode circuit OR merely provide a source signal for an on-screen display of received signal level. The circuit as shown is relatively simple, however.

Bob ¡ª KKR

Inline image


On Wednesday, October 28, 2020, 7:06:58 AM EDT, IW4AJR Loris <lorisbollina@...> wrote:


On the CCARC (Carroll County Amateur Radio Club, Inc.) website I found a very interesting article on automatic gain control that is worth reading!
Without many frills Carol makes us understand that an AGC (automatic gain control) on the IF of the uBITX, due to the nature of the amps used (bidirectional), is very complex to make at this level of the circuit ...
therefore ? ...
Much better and less invasive to act directly on the volume control, implementing a simple but effective automatic volume control (AVC)!
Think man ... think ...
A little less software and a little more electronic experimentation and, with much less effort, very complex problems can be solved!
Think man ... think !
Greetings to all, Loris IW4AJR


Re: Simple UBITX Test Set

 

If? Ashhar Farhan can calibrate?the UBITX by the PC via web, what?about a web app to decode SSTV?
It can be done with laptop?and easypal?for example listening to the hand held, but it will be great a?web page with a chat, then the images there, and not using easypal.
I also know there are pages to load the images, but I am talking web app instead of easypal.

That would be great.

On Wed, Oct 28, 2020 at 3:28 AM Tom, wb6b <wb6b@...> wrote:
On Tue, Oct 27, 2020 at 09:55 AM, Evan Hand wrote:
For the stock uBITX Ashhar Farhan published a video on how to calibrate and set the BFO:
Interesting. Using a Chrome web browser based audio spectrum analyzer to set the filter passband based on the noise coming out of the uBitx speaker is really cool. The spectrum analyzer looks fun to play with even if you are not aligning your uBitx filter bandpass at the moment.

I think I try this on some other radios, like my vintage Kenwood, to see the difference between the SSB, AM and CW filters, just of fun.

Tom, wb6b


Re: uBitX V6 no transmit power Round 2 #ubitx-help #tx #ubitxv6

 

Yes.?
Could be anywhere in the antenna system with a DC path to the rig.


On Wed, Oct 28, 2020 at 08:22 AM, Jonas Sanamon wrote:
I think a 47kohm resistor from antenna to ground ?at antenna intake would solve it.?


Re: A strange thing about calibration!!

 

Re,

there may be things to dig around here in manager

cdt


Re: uBitX V6 no transmit power Round 2 #ubitx-help #tx #ubitxv6

 

¿ªÔÆÌåÓý

I think a 47kohm resistor from antenna to ground ?at antenna intake would solve it.?

Cheers,?
Jonas?

28 okt. 2020 kl. 15:51 skrev Jerry Gaffke via groups.io <jgaffke@...>:

?Jonas,

Good point.
Might be best to have the choke in the antenna system somewhere, not in the rig.

Jerry, KE7ER


On Wed, Oct 28, 2020 at 04:58 AM, Jonas Sanamon wrote:
Those DC-paths might prevent static build-up, but that might not be sufficient if the uBitx is unconnected and static builds up on antenna and then it is connected?
?


Re: Simple UBITX Test Set

 

Vic,

I assume you are matching the hetrodyne of the uBitx BFO plus the WWV carrier
against the audio tone from an AM radio also tuned to WWV.
The tones from WWV flip between 500hz and 600hz each minute, let's go with 500hz.
So you might set the uBitx frequency display to 10.000500 mhz, then adjust?
the calibration variable?si5351bx_vcoa (reloading all three Si5351 oscillators
with each adjustment) until the hetrodyne is exactly the 500hz you hear on the
AM radio.? I'm assuming the uBitx is in LSB mode for this example, with the BFO
500hz above the carrier and not below it.

This need not be stuck with WWV, could use any shortwave carrier of known frequency.
Just set the CW sidetone from the NANO to 500hz for your audio reference,
must be attenuated sufficiently.? Or a 500hz tone from your laptop or smartphone.



Another method would detect the sub-audible beat note out of the demodulator,
perhaps with a DVM.??

Jerry, KE7ER



On Wed, Oct 28, 2020 at 04:54 AM, Vic WA4THR wrote:

Regarding trying to calibrate with WWV, it actually is easier if you have a second AM receiver when WWV is sending tones. You can then match the tone frequency between the uBitX and the AM receiver much easier than when zero beating as you can do that within a few cycles as opposed to losing the low frequency notes perhaps 100's of cycles before zero beat. Note, to be accurate the 2nd receiver needs to be AM, which eliminates that receiver's error which could be added to the perceived tone frequency if using SSB. That is the technique I used on mine and it is dead on frequency.

=Vic=


A strange thing about calibration!!

 

Hello,
I don¡¯t know if anyone has ever put an oscilloscope on the BF part of the audio amplifier.
?Example connect to hp output with sufficient level.
I notice that the calibragre gives a pure signal of sound (a little noise in fact). No oscillation.
Not to mention setting the BFO, and after validating your calibration, you need to reinitialize your Ubitx.
And this is where it becomes fun, you find your sound (Everything seems normal to you), but each time, it is in fact modulated (Like from the AM) in 16.6 Khtz.
You can¡¯t hear it. This frequency), because your ears can¡¯t hear that frequency. And if you are a little old, these are more than 20 years old ears!! LOL
You can resume your calibration in all directions, it is always the same result.
I can¡¯t explain the reason for this phenomenon. There may be a parameter to change?
It¡¯s not a nuisance for listening, but there has to be an answer.

If some one may test also to see if i have this ?

cdt


Re: ?BITX ... AGC or AVC?

 

AmatuerRadioKits sells an AGC that, per instructions, connects to the receiver input first IF at R10.? It does appear to work, though I have not done extensive testing.

I am only offering up this option to show that others have done the IF gain adjustments, though not in the 2nd IF stage as is suggested in this topic.

Here is the link to the files for the kit:


73
Evan
AC9TU