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I wired my uBITX according to the diagrams I found at
I just got it working this week. The only problem was a defective volume
control pot. The Chassis that goes with the ubitx has a hole in the front
panel labeled TX-RX and the parts include a three legged LED. But the page
does not show how or where to hook it up. Can anyone help me?
I have bookmarked the AGC circuit that came out just a few minutes ago and
I'll probably need help on which trace to cut.
73.
Max. K 4 O DS.
I've Never Lost the Wonder.
Email: max@...
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Hi Max,
I'm assuming that you have an enclosure from Sunil (VU3SUA) by the description.? He has pictures on his website showing how he has done the? RX/TX LED wire-up.
The website is??the pictures are the second and third from the last.
He is picking up the 12V RX and TX control signals from the uBITX RX/TX relay by soldering wires to the bottom of the uBITX PCB.? He also picks up the ground from the relay.? He then routes 3 wires (RX,TX,GND) to a small prototype board with series current limiting resistors on RX and TX.? No reason you couldn't put your resistors anywhere along that route.? I would have put them right on the PCB.
Regards,
Gary
AG5TX
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Thank you Gary. ? Regards. ? Max K 4 O D S. ? I've Never Lost the Wonder. ? Antique Electronics Site: ? ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Gary Anderson
Sent: Thursday, April 19, 2018 6:03 AM
To: [email protected]
Subject: Re: [BITX20] Transmit indicator light. ? Hi Max,
I'm assuming that you have an enclosure from Sunil (VU3SUA) by the description.? He has pictures on his website showing how he has done the? RX/TX LED wire-up.
The website is??the pictures are the second and third from the last.
He is picking up the 12V RX and TX control signals from the uBITX RX/TX relay by soldering wires to the bottom of the uBITX PCB.? He also picks up the ground from the relay.? He then routes 3 wires (RX,TX,GND) to a small prototype board with series current limiting resistors on RX and TX.? No reason you couldn't put your resistors anywhere along that route.? I would have put them right on the PCB.
Regards,
Gary
AG5TX
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Hi Gary. ? I’ve been kind of busy and just got around to checking out this link.? It didn’t lead me to anything useful.? ? Regards. ? Max K 4 O D S. ? I've Never Lost the Wonder. ? Antique Electronics Site: ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Gary Anderson
Sent: Thursday, April 19, 2018 6:03 AM
To: [email protected]
Subject: Re: [BITX20] Transmit indicator light. ? Hi Max,
I'm assuming that you have an enclosure from Sunil (VU3SUA) by the description.? He has pictures on his website showing how he has done the? RX/TX LED wire-up.
The website is??the pictures are the second and third from the last.
He is picking up the 12V RX and TX control signals from the uBITX RX/TX relay by soldering wires to the bottom of the uBITX PCB.? He also picks up the ground from the relay.? He then routes 3 wires (RX,TX,GND) to a small prototype board with series current limiting resistors on RX and TX.? No reason you couldn't put your resistors anywhere along that route.? I would have put them right on the PCB.
Regards,
Gary
AG5TX
|
Max,
Here are the direct links to the images showing TX/RX LED wire-up for Sunil's (VU3SUA)?enclosure.
3 wires soldered to PCB:
Proto board connected to LED with series resistors:
If this doesn't work for you, I can include the images in an email to the address shown on your funwithtubes site.
Regards,
Gary
AG5TX
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In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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Thank you.? These links look good. ? Regards. ? Max K 4 O D S. ? I've Never Lost the Wonder. ? Antique Electronics Site: ? ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Gary Anderson
Sent: Friday, April 20, 2018 9:33 AM
To: [email protected]
Subject: Re: [BITX20] Transmit indicator light. ? Max,
Here are the direct links to the images showing TX/RX LED wire-up for Sunil's (VU3SUA)?enclosure.
3 wires soldered to PCB:
Proto board connected to LED with series resistors:
If this doesn't work for you, I can include the images in an email to the address shown on your funwithtubes site.
Regards,
Gary
AG5TX
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Another LED approach that works well is what's used in OZQRP's MDT DSB tx.?
As the uBitx is higher power it may be possible to use a smaller coupling capacitor (try 5-10pF instead of 22pF - not tried by me yet)
Circuit on p15 of the manual.?
73, Peter VK3YE
?
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Circuit diagram to enable this idea?..
On Sat, Apr 21, 2018, 3:51 AM Don, ND6T via Groups.Io <nd6t_6= [email protected]> wrote: In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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Show quoted text
On Mon, Jun 18, 2018 at 8:07 AM Praba Karan < vu3dxr@...> wrote: Circuit diagram to enable this idea?..
On Sat, Apr 21, 2018, 3:51 AM Don, ND6T via Groups.Io <nd6t_6= [email protected]> wrote: In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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The following is a question not a statement.
Typically the ant lead is at the back of a radio case and the LED indicator would be on the front panel. Wouldn't running the wires feeding the LED that distance cause a potential of rf radiation into the radio?
Roy WA0YMH
On Mon, Jun 18, 2018 at 8:07 AM Praba Karan < vu3dxr@...> wrote: Circuit diagram to enable this idea?..
On Sat, Apr 21, 2018, 3:51 AM Don, ND6T via Groups.Io <nd6t_6= [email protected]> wrote: In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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Roy WA0YMH
Probably could use a diode rectifier and filter cap at the toroid location and run
DC to the front panel LED.? I have never tried that because radiated RF inside
the chassis has never been a problem.
Using a rectifier and filter cap could also let you measure RF current on an ADC
input of the Arduino.? Interesting thought that if you measure RF current and RF
voltage at the antenna jack it might be possible to calculate antenna impedance.
Arv? K7HKL
_._
The following is a question not a statement.
Typically the ant lead is at the back of a radio case and the LED indicator would be on the front panel. Wouldn't running the wires feeding the LED that distance cause a potential of rf radiation into the radio?
Roy WA0YMH
On Mon, Jun 18, 2018 at 8:07 AM Praba Karan < vu3dxr@...> wrote: Circuit diagram to enable this idea?..
On Sat, Apr 21, 2018, 3:51 AM Don, ND6T via Groups.Io <nd6t_6= [email protected]> wrote: In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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I bet that someone? could come up with a circuit of a diode, capacitor and resistor to feed into the same analog pin as the s-meter in the modified software so you could see about how much power was going out.
Seems simple enough to me, but I do not have the coding skills to do that.
On Mon, Jun 18, 2018 at 2:10 PM, Arv Evans <arvid.evans@...> wrote: Roy WA0YMH
Probably could use a diode rectifier and filter cap at the toroid location and run
DC to the front panel LED.? I have never tried that because radiated RF inside
the chassis has never been a problem.
Using a rectifier and filter cap could also let you measure RF current on an ADC
input of the Arduino.? Interesting thought that if you measure RF current and RF
voltage at the antenna jack it might be possible to calculate antenna impedance.
Arv? K7HKL
_._
The following is a question not a statement.
Typically the ant lead is at the back of a radio case and the LED indicator would be on the front panel. Wouldn't running the wires feeding the LED that distance cause a potential of rf radiation into the radio?
Roy WA0YMH
On Mon, Jun 18, 2018 at 8:07 AM Praba Karan < vu3dxr@...> wrote: Circuit diagram to enable this idea?..
On Sat, Apr 21, 2018, 3:51 AM Don, ND6T via Groups.Io <nd6t_6= [email protected]> wrote: In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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Phase is important, if you are measuring current and voltage at the antenna port you will also want to measure the phase angle between the two. A Tandem Match more or less measures voltage and current into the antenna. This one is $12:? ? ?? T1 is a current transformer, T2 is a voltage transformer, Actually, a Tandem Match adds the voltage and current readings in phase and out of phase from which an SWR relative to 50 ohms can be calculated. From those readings, can also calculate forward and reverse power in Watts.. Primary trick on a Tandem Match is that the voltage and current are scaled such that if driving a 50 ohm load, the sum of the two when out of phase is zero.?? The Bruene and Monimatch designs do about the same as a Tandem Match.?? This 1959 Bruene article is a classic, recommended:?? Here's a full analysis of the Tandem Match:?? Another tutorial on SWR meters:?? There are others. An advantage of the Tandem Match is that the transformer ratios pretty much calibrate it for both absolute power into 50 ohms, and SWR.? Unlike the resistive bridges typical of qrp swr meters, a Tandem Match (or Bruene or Monimatch and friends) can remain inline to monitor correct antenna functioning while operating the transmitter. If you really want to explore antenna impedances to 440mhz and maybe do two port measurements, check out?Kee's AQRP Vector Impedance Analyzer near the bottom of this webpage: ? ?? That one really does measure voltage and current into the antenna, along with the phase angle. And can do much much more. Jerry, KE7ER ? On Mon, Jun 18, 2018 at 11:10 am, Arv Evans wrote:
Probably could use a diode rectifier and filter cap at the toroid location and run
DC to the front panel LED.? I have never tried that because radiated RF inside
the chassis has never been a problem.
Using a rectifier and filter cap could also let you measure RF current on an ADC
input of the Arduino.? Interesting thought that if you measure RF current and RF
voltage at the antenna jack it might be possible to calculate antenna impedance.?
|
very good explanations Jerry. an another realisation
Gilles F1BFU / FR
Phase is important, if you are measuring current and voltage at the antenna port
you will also want to measure the phase angle between the two.
A Tandem Match more or less measures voltage and current into the antenna.
This one is $12:? ? ??
T1 is a current transformer, T2 is a voltage transformer,
Actually, a Tandem Match adds the voltage and current readings in phase and out of phase
from which an SWR relative to 50 ohms can be calculated.
From those readings, can also calculate forward and reverse power in Watts..
Primary trick on a Tandem Match is that the voltage and current are scaled such that if driving a 50 ohm load,
the sum of the two when out of phase is zero.??
The Bruene and Monimatch designs do about the same as a Tandem Match.??
This 1959 Bruene article is a classic, recommended:??
Here's a full analysis of the Tandem Match:??
Another tutorial on SWR meters:??
There are others.
An advantage of the Tandem Match is that the transformer ratios pretty much calibrate it
for both absolute power into 50 ohms, and SWR.?
Unlike the resistive bridges typical of qrp swr meters, a Tandem Match (or Bruene or Monimatch and friends)
can remain inline to monitor correct antenna functioning while operating the transmitter.
If you really want to explore antenna impedances to 440mhz and maybe do two port measurements,
check out?Kee's AQRP Vector Impedance Analyzer near the bottom of this webpage:
? ??
That one really does measure voltage and current into the antenna, along with the phase angle.
And can do much much more.
Jerry, KE7ER
?
On Mon, Jun 18, 2018 at 11:10 am, Arv Evans wrote:
Probably could use a diode rectifier and filter cap at the toroid location and run
DC to the front panel LED.? I have never tried that because radiated RF inside
the chassis has never been a problem.
Using a rectifier and filter cap could also let you measure RF current on an ADC
input of the Arduino.? Interesting thought that if you measure RF current and RF
voltage at the antenna jack it might be possible to calculate antenna impedance.?
|
Arv, so you have used this method in a QRP transceiver? Did you run the wire to the LED as a simple twisted pair or a piece of mini coax?
Roy WA0YMH
Roy WA0YMH
Probably could use a diode rectifier and filter cap at the toroid location and run
DC to the front panel LED.? I have never tried that because radiated RF inside
the chassis has never been a problem.
Using a rectifier and filter cap could also let you measure RF current on an ADC
input of the Arduino.? Interesting thought that if you measure RF current and RF
voltage at the antenna jack it might be possible to calculate antenna impedance.
Arv? K7HKL
_._
The following is a question not a statement.
Typically the ant lead is at the back of a radio case and the LED indicator would be on the front panel. Wouldn't running the wires feeding the LED that distance cause a potential of rf radiation into the radio?
Roy WA0YMH
On Mon, Jun 18, 2018 at 8:07 AM Praba Karan < vu3dxr@...> wrote: Circuit diagram to enable this idea?..
On Sat, Apr 21, 2018, 3:51 AM Don, ND6T via Groups.Io <nd6t_6= [email protected]> wrote: In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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Jerry
Beauty of the little toroid and LED trick is its simplicity and ease of use.
Of course if we were to build something like this inside a BITX it should probably be
a real SWR bridge with phase compensation and so on.
Arv
_._
On Mon, Jun 18, 2018 at 1:22 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: Phase is important, if you are measuring current and voltage at the antenna port
you will also want to measure the phase angle between the two.
A Tandem Match more or less measures voltage and current into the antenna.
This one is $12:? ? ??
T1 is a current transformer, T2 is a voltage transformer,
Actually, a Tandem Match adds the voltage and current readings in phase and out of phase
from which an SWR relative to 50 ohms can be calculated.
From those readings, can also calculate forward and reverse power in Watts..
Primary trick on a Tandem Match is that the voltage and current are scaled such that if driving a 50 ohm load,
the sum of the two when out of phase is zero.??
The Bruene and Monimatch designs do about the same as a Tandem Match.??
This 1959 Bruene article is a classic, recommended:??
Here's a full analysis of the Tandem Match:??
Another tutorial on SWR meters:??
There are others.
An advantage of the Tandem Match is that the transformer ratios pretty much calibrate it
for both absolute power into 50 ohms, and SWR.?
Unlike the resistive bridges typical of qrp swr meters, a Tandem Match (or Bruene or Monimatch and friends)
can remain inline to monitor correct antenna functioning while operating the transmitter.
If you really want to explore antenna impedances to 440mhz and maybe do two port measurements,
check out?Kee's AQRP Vector Impedance Analyzer near the bottom of this webpage:
? ??
That one really does measure voltage and current into the antenna, along with the phase angle.
And can do much much more.
Jerry, KE7ER
?
On Mon, Jun 18, 2018 at 11:10 am, Arv Evans wrote:
Probably could use a diode rectifier and filter cap at the toroid location and run
DC to the front panel LED.? I have never tried that because radiated RF inside
the chassis has never been a problem.
Using a rectifier and filter cap could also let you measure RF current on an ADC
input of the Arduino.? Interesting thought that if you measure RF current and RF
voltage at the antenna jack it might be possible to calculate antenna impedance.?
|
Roy? WA0YMH
Yes.? It works fine with just a couple inches of twisted hookup wire between toroid
and LED.? Adjust the number of turns for slightly less than full brightness at full
power.? FT37-43 cores work well, but for 40M you can use one of the clip-on ferrites
or the green core liberated from a dead CFL light bulb.?
This is not a particularly new or original idea.? It has been floating around the airwaves
for many years.?
Arv? K7HKL
_._
Arv, so you have used this method in a QRP transceiver? Did you run the wire to the LED as a simple twisted pair or a piece of mini coax?
Roy WA0YMH
Roy WA0YMH
Probably could use a diode rectifier and filter cap at the toroid location and run
DC to the front panel LED.? I have never tried that because radiated RF inside
the chassis has never been a problem.
Using a rectifier and filter cap could also let you measure RF current on an ADC
input of the Arduino.? Interesting thought that if you measure RF current and RF
voltage at the antenna jack it might be possible to calculate antenna impedance.
Arv? K7HKL
_._
The following is a question not a statement.
Typically the ant lead is at the back of a radio case and the LED indicator would be on the front panel. Wouldn't running the wires feeding the LED that distance cause a potential of rf radiation into the radio?
Roy WA0YMH
On Mon, Jun 18, 2018 at 8:07 AM Praba Karan < vu3dxr@...> wrote: Circuit diagram to enable this idea?..
On Sat, Apr 21, 2018, 3:51 AM Don, ND6T via Groups.Io <nd6t_6= [email protected]> wrote: In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
|
toggle quoted message
Show quoted text
Roy? WA0YMH
Yes.? It works fine with just a couple inches of twisted hookup wire between toroid
and LED.? Adjust the number of turns for slightly less than full brightness at full
power.? FT37-43 cores work well, but for 40M you can use one of the clip-on ferrites
or the green core liberated from a dead CFL light bulb.?
This is not a particularly new or original idea.? It has been floating around the airwaves
for many years.?
Arv? K7HKL
_._
Arv, so you have used this method in a QRP transceiver? Did you run the wire to the LED as a simple twisted pair or a piece of mini coax?
Roy WA0YMH
Roy WA0YMH
Probably could use a diode rectifier and filter cap at the toroid location and run
DC to the front panel LED.? I have never tried that because radiated RF inside
the chassis has never been a problem.
Using a rectifier and filter cap could also let you measure RF current on an ADC
input of the Arduino.? Interesting thought that if you measure RF current and RF
voltage at the antenna jack it might be possible to calculate antenna impedance.
Arv? K7HKL
_._
The following is a question not a statement.
Typically the ant lead is at the back of a radio case and the LED indicator would be on the front panel. Wouldn't running the wires feeding the LED that distance cause a potential of rf radiation into the radio?
Roy WA0YMH
On Mon, Jun 18, 2018 at 8:07 AM Praba Karan < vu3dxr@...> wrote: Circuit diagram to enable this idea?..
On Sat, Apr 21, 2018, 3:51 AM Don, ND6T via Groups.Io <nd6t_6= [email protected]> wrote: In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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Don, ND6T
Peter Parker