Date   

Re: Bias current problems

AA7US
 

That's a good point to remember about the CS series transceivers having higher RX current due to the operation of the sandwich VFO.

Keep in mind the sandwich VFO assembly instructions mention you can disable (destroy) the status LED on the Arduio Pro Mini's circuit board to save 1.5mA of current consumption.  I opted not to do this because I was too worried I'd inadvertently harm the circuit board.

73,

John
AA7US

---In CHINA_QRP@..., <rongxh@...> wrote :

The RX mode current is increased from around 40-mA to around 70-mA for CS series because the added Sandwich digital VFO will consume more.

Thanks,
Adam


Re: Bias current problems

Brian Schmitt
 

Bob,

If I remeber correctly from my build of knq7a, the counterclockwise  amperage is approx 480mA (540mA - 60mA). The pot gets turned clockwise to increase the bias approx  60mA up to 540mA. 

I do remeber having to re read that part of the manual a few times.

Brian



On Sat, Jul 22, 2017 at 3:56 AM, vk2aor@... [CHINA_QRP]
wrote:
 

Hi

Working on 40m Txcr with Ver 2.2 board.

A little confused about the Bias Current setting.    The procedure says with the bias setting pot turned fully anti-clockwise start turning it clockwise slowly until the current increases 60mA to about 0.54A (that is 540mA).

This seems like a high current.   I have worked on another Tx where the idle current was 60mA only.

 

What current should be drawn with the pot in the anti-clock position?   Is my understanding out  or is it a typing error?


I managed to destroy the final FET and have replaced it, also removed the bias pot to check it, appears ok .

I have made up a test mic plug with a switch as PTT and have a 2 tone board for checking peak envelope power.    The Rx draws 44mA and when the the switch (PTT) is operated the current goes to 1200mA and am unable to adjust it with the bias pot.


 The board was built by a friend and trying to help him out.     

The  Low Pass Filter coils have the correct number of turns (15) but seem loosely wound,  check the circuits with an ohm meter and all appear ok.  Check the toroid transformers and the same applies loose windings but correct turns and continuity with an ohmmeter.   The receiver seems to be working fine.   Just Stuck on the bias current.   Any help would be appreciated.


Bob VK2AOR


Re: Bias current problems

n7rgw
 

Don't forget to make sure the Final FET is insulated from the case.


On Saturday, July 22, 2017 4:56 AM, "vk2aor@... [CHINA_QRP]" wrote:


 
Hi
Working on 40m Txcr with Ver 2.2 board.
A little confused about the Bias Current setting.    The procedure says with the bias setting pot turned fully anti-clockwise start turning it clockwise slowly until the current increases 60mA to about 0.54A (that is 540mA).
This seems like a high current.   I have worked on another Tx where the idle current was 60mA only.
 
What current should be drawn with the pot in the anti-clock position?   Is my understanding out  or is it a typing error?

I managed to destroy the final FET and have replaced it, also removed the bias pot to check it, appears ok .
I have made up a test mic plug with a switch as PTT and have a 2 tone board for checking peak envelope power.    The Rx draws 44mA and when the the switch (PTT) is operated the current goes to 1200mA and am unable to adjust it with the bias pot.

 The board was built by a friend and trying to help him out.     
The  Low Pass Filter coils have the correct number of turns (15) but seem loosely wound,  check the circuits with an ohm meter and all appear ok.  Check the toroid transformers and the same applies loose windings but correct turns and continuity with an ohmmeter.   The receiver seems to be working fine.   Just Stuck on the bias current.   Any help would be appreciated.

Bob VK2AOR



Re: Bias current problems

JOHN CRONHELM
 

Thanks John,
Your explanation is excellent and very clear.  Will help me a lot when I get to that point.
Regards,
John  Vo1jcc

On Jul 22, 2017 1:15 PM, "landrjoh@... [CHINA_QRP]" <CHINA_QRP@...> wrote:
 

Hey gang,


I just finished assembling a CS-40 yesterday and went through the TX alignment.  After reading about all the destroyed IRF510's, I was a bit nervous when setting the bias current.

Here's how it's done:

1. Connect ammeter in the transceiver's power supply lead.  Keep in mind that the current can approach 1.5 amps during the entire alignment process (including TX power peaking), so pick an appropriate range on your ammeter.

2. Make double (triple) sure the SET BIAS trimmer (pot) on the main PCB is fully counter clockwise.

3. IF you've already fiddled with the TX IFT coils, I'd suggest returning them to their factory setting by screwing them back fully clockwise, gently.

4. Apply power to the transceiver.  Take note of the idle receive current draw.  My CS-40 shows about 0.07 amps at 12.7v input power.

5. Key up the transceiver via the PTT switch but DO NOT TALK into the mic.  Write down the current shown on the ammeter for reference.  My CS-40 showed 0.54 amps.

6. With the PTT switch still pressed, turn the SET BIAS trimmer clockwise VERY VERY VERY slowly while carefully watching the ammeter for an increase in current.

7. Somewhere beyond the middle travel of the SET BIAS trimmer's rotation the power supply current will begin to increase.  Occasionally pause between SLOWLY turning the SET BIAS trimmer to let the supply current stabilize.

8. Once the supply current has increased (and stabilized) to approx. 60mA (0.06 amps) beyond the current you started with, STOP.  In the case of my CS-40, I stopped at 0.59 amps total.  That works out as 0.54 amps beginning + 0.05 amps increase of bias current.

9. Unkey the PTT switch.

10. Now you can peak the TX band pass filters (IFT coils) for maximum TX power following the instructions in the assembly manual.

My CS-40 wound up with approx. 8 watts of TX out at full modulation with 12.7v input power.

Hope this helps clear things up for someone.

73,

John
AA7US



Re: Bias current problems

Adam Rong
 

Thanks, John.

In TX mode, even there is no voice to drive the RF output, the current consumption is still much bigger than RX mode because of the TX chain bias current and relay coil current consumption. It is the nature of SSB mode that you get RF output only when you speak to microphone. You speak louder, you get higher power before it is saturated.

The RX mode current is increased from around 40-mA to around 70-mA for CS series because the added Sandwich digital VFO will consume more.

Thanks,
Adam

在 2017年7月22日,下午11:45,landrjoh@... [CHINA_QRP] <CHINA_QRP@...> 写道:

Hey gang,


I just finished assembling a CS-40 yesterday and went through the TX alignment.  After reading about all the destroyed IRF510's, I was a bit nervous when setting the bias current.

Here's how it's done:

1. Connect ammeter in the transceiver's power supply lead.  Keep in mind that the current can approach 1.5 amps during the entire alignment process (including TX power peaking), so pick an appropriate range on your ammeter.

2. Make double (triple) sure the SET BIAS trimmer (pot) on the main PCB is fully counter clockwise.

3. IF you've already fiddled with the TX IFT coils, I'd suggest returning them to their factory setting by screwing them back fully clockwise, gently.

4. Apply power to the transceiver.  Take note of the idle receive current draw.  My CS-40 shows about 0.07 amps at 12.7v input power.

5. Key up the transceiver via the PTT switch but DO NOT TALK into the mic.  Write down the current shown on the ammeter for reference.  My CS-40 showed 0.54 amps.

6. With the PTT switch still pressed, turn the SET BIAS trimmer clockwise VERY VERY VERY slowly while carefully watching the ammeter for an increase in current.

7. Somewhere beyond the middle travel of the SET BIAS trimmer's rotation the power supply current will begin to increase.  Occasionally pause between SLOWLY turning the SET BIAS trimmer to let the supply current stabilize.

8. Once the supply current has increased (and stabilized) to approx. 60mA (0.06 amps) beyond the current you started with, STOP.  In the case of my CS-40, I stopped at 0.59 amps total.  That works out as 0.54 amps beginning + 0.05 amps increase of bias current.

9. Unkey the PTT switch.

10. Now you can peak the TX band pass filters (IFT coils) for maximum TX power following the instructions in the assembly manual.

My CS-40 wound up with approx. 8 watts of TX out at full modulation with 12.7v input power.

Hope this helps clear things up for someone.

73,

John
AA7US




Re: Bias current problems

AA7US
 

Hey gang,

I just finished assembling a CS-40 yesterday and went through the TX alignment.  After reading about all the destroyed IRF510's, I was a bit nervous when setting the bias current.

Here's how it's done:

1. Connect ammeter in the transceiver's power supply lead.  Keep in mind that the current can approach 1.5 amps during the entire alignment process (including TX power peaking), so pick an appropriate range on your ammeter.

2. Make double (triple) sure the SET BIAS trimmer (pot) on the main PCB is fully counter clockwise.

3. IF you've already fiddled with the TX IFT coils, I'd suggest returning them to their factory setting by screwing them back fully clockwise, gently.

4. Apply power to the transceiver.  Take note of the idle receive current draw.  My CS-40 shows about 0.07 amps at 12.7v input power.

5. Key up the transceiver via the PTT switch but DO NOT TALK into the mic.  Write down the current shown on the ammeter for reference.  My CS-40 showed 0.54 amps.

6. With the PTT switch still pressed, turn the SET BIAS trimmer clockwise VERY VERY VERY slowly while carefully watching the ammeter for an increase in current.

7. Somewhere beyond the middle travel of the SET BIAS trimmer's rotation the power supply current will begin to increase.  Occasionally pause between SLOWLY turning the SET BIAS trimmer to let the supply current stabilize.

8. Once the supply current has increased (and stabilized) to approx. 60mA (0.06 amps) beyond the current you started with, STOP.  In the case of my CS-40, I stopped at 0.59 amps total.  That works out as 0.54 amps beginning + 0.05 amps increase of bias current.

9. Unkey the PTT switch.

10. Now you can peak the TX band pass filters (IFT coils) for maximum TX power following the instructions in the assembly manual.

My CS-40 wound up with approx. 8 watts of TX out at full modulation with 12.7v input power.

Hope this helps clear things up for someone.

73,

John
AA7US


Re: Bias current problems

JOHN CRONHELM
 

Sorry Bob,
That's not the question I was asking.  Where on the PCB should I touch with the positive probe to read the bias current.
Many thanks,
John vo1jcc.


On Jul 22, 2017, at 11:10 AM, Robert Hudson vk2aor@... [CHINA_QRP] <CHINA_QRP@...> wrote:

 

To John


Just re-read your question posed about where you check the current amps.

" As a point of interest where do you check the current amps. From which point to ground? "

When you check voltage you use  say a voltmeter from earth to a point where voltage might be expected , say a better.  When you check current /amps you need to have you multimeter switch to the amps setting and it is connected in series.   Maybe you had errant finger on the keyboard.

Best wishes


Bob Hudson








Re: Bias current problems

Robert Hudson
 

To John

Just re-read your question posed about where you check the current amps.

" As a point of interest where do you check the current amps. From which point to ground? "

When you check voltage you use  say a voltmeter from earth to a point where voltage might be expected , say a better.  When you check current /amps you need to have you multimeter switch to the amps setting and it is connected in series.   Maybe you had errant finger on the keyboard.

Best wishes


Bob Hudson








Re: Bias current problems

Robert Hudson
 

Hi John

I use an ammeter in the supply line in series to read the current.   The receiver draws 44mA and if the Bias current  was 60mA then the total current draw would be 100mA.   It actually might be a bit less because I think some of the circuit is switched off when the PTT is pressed.  

I recently bought an FT-847 from a deceased estate which was dismantled and in a cardboard box with most of the covers missing.   I have been able to re-connect it and stall worked with VHF, UHF and HF/50mhz.  The only problem was the HF/50Mhz PA board (Power Amplifier board).  The problem was there was no bias current .   After looking around and getting the service manual and staying the circuit I found the bias pot was open circuit.  The interesting thing was that it had a 2 pin header with a link connected for normal use and you could take the link off and connect an ammeter read the bias current only with out the complication of reading the whole radio current draw.      

The way the instruction is written does not make sense to me.  So hoping to get some further explanation.   I have some other information as well to progress with the testing by shorting pins 2 and 3 which makes it operate in the AM mode of one of the NE602 chips but have to read further.   Still need to understand the Bias current setup.

Hope that explains some it for you John.


Bob Hudson








Re: Bias current problems

JOHN CRONHELM
 

Hi Bob,
Should be soon checking this myself.  As a point of interest where do you check the current amps. From which point to ground?  Sorry can't help you with your problem.
John, vo1jcc.


On Jul 22, 2017, at 8:26 AM, vk2aor@... [CHINA_QRP] <CHINA_QRP@...> wrote:

 

Hi

Working on 40m Txcr with Ver 2.2 board.

A little confused about the Bias Current setting.    The procedure says with the bias setting pot turned fully anti-clockwise start turning it clockwise slowly until the current increases 60mA to about 0.54A (that is 540mA).

This seems like a high current.   I have worked on another Tx where the idle current was 60mA only.

 

What current should be drawn with the pot in the anti-clock position?   Is my understanding out  or is it a typing error?


I managed to destroy the final FET and have replaced it, also removed the bias pot to check it, appears ok .

I have made up a test mic plug with a switch as PTT and have a 2 tone board for checking peak envelope power.    The Rx draws 44mA and when the the switch (PTT) is operated the current goes to 1200mA and am unable to adjust it with the bias pot.


 The board was built by a friend and trying to help him out.     

The  Low Pass Filter coils have the correct number of turns (15) but seem loosely wound,  check the circuits with an ohm meter and all appear ok.  Check the toroid transformers and the same applies loose windings but correct turns and continuity with an ohmmeter.   The receiver seems to be working fine.   Just Stuck on the bias current.   Any help would be appreciated.


Bob VK2AOR


Bias current problems

Robert Hudson
 

Hi

Working on 40m Txcr with Ver 2.2 board.

A little confused about the Bias Current setting.    The procedure says with the bias setting pot turned fully anti-clockwise start turning it clockwise slowly until the current increases 60mA to about 0.54A (that is 540mA).

This seems like a high current.   I have worked on another Tx where the idle current was 60mA only.

 

What current should be drawn with the pot in the anti-clock position?   Is my understanding out  or is it a typing error?


I managed to destroy the final FET and have replaced it, also removed the bias pot to check it, appears ok .

I have made up a test mic plug with a switch as PTT and have a 2 tone board for checking peak envelope power.    The Rx draws 44mA and when the the switch (PTT) is operated the current goes to 1200mA and am unable to adjust it with the bias pot.


 The board was built by a friend and trying to help him out.     

The  Low Pass Filter coils have the correct number of turns (15) but seem loosely wound,  check the circuits with an ohm meter and all appear ok.  Check the toroid transformers and the same applies loose windings but correct turns and continuity with an ohmmeter.   The receiver seems to be working fine.   Just Stuck on the bias current.   Any help would be appreciated.


Bob VK2AOR


Re: KN-Q7A Board rev. 2.2 complete circuit diagram.

Adam Rong
 

Larry's way is okay but not the best. Please follow the way in manual for good performance.

于 2017-7-18 7:53, John Cronhelm johncronhelm@... [CHINA_QRP] 写道:

 
The winding of the 3 smaller toroids that you describe is very different from the way it is described in the manual.  Not sure why the difference.
John, vo1jcc.


On Jul 17, 2017, at 2:31 PM, larry.lovell@... [CHINA_QRP] <CHINA_QRP@...> wrote:

 

The difference (main) between Rev C and Rev D is the addition of a speaker mike capability.  Thus, an additional pin is added to the printed circuit board.  The speaker/mike will work with either Rev C or Rev D boards, but you would have to run a wire to the microphone connector (Pin 8) from the speaker connection.

You can download the Rev D manual and other bits of information from my website http://www.larvell.net/Side_Left_B/Download.htm.   (www.qrvtronics.com)

A couple of issues that I have found with power output are as follows.  Make sure that you have wound the toroids properly (easy to miss-count).  See: http://www.larvell.net/Side_Left_B/files/KN-Q7A_App_WindingTheToroid.pdf for additional help.  Make sure that the wire leads have been properly stripped.  With an ohmmeter, you can check the points on the printed circuit boards for the coils making contact.  

The next issue is to check the Transmit Band Pass filter for proper tuning.  If you have a signal generator and an oscilloscope, you can adjust the filter without power to your radio.  I inject the signal at pin 4 on the NE602 and check the signal with the oscilloscope on the 680 ohm resistor.  Adjust the coils for maximum amplitude.

If all that fails, Short Pin 2 and 3 on the NE602 nearest the IF crystal.  This will take the radio out of SSB and you should transmit only the carrier wave.

Check to see where you are loosing the signal.  With an oscilloscope check the amplitude on Pin 4 of the NE602.  Press and release the push-to-talk button on each test.  Next look at the amplitude on the SMD part C3357 on the tab.  The amplitude should have increased.  Next check the amplitude on the Collector of the D882 transistor.  Again, the amplitude should have increased.  Finally, check the amplitude on the 104 cap that leads into the final High Pass Filter section.  You should get a very large voltage swing.

One other thing that I will do just to check the transmit section would be to inject a small signal at the carrier frequency at the 680 ohm resistor.  Try about 50 mV to 100 mV if possible.  Then check each step of the transmitter with an oscilloscope.

You can contact me directly at n7rgw@...
Good luck
Larry


 


Re: KN-Q7A Board rev. 2.2 complete circuit diagram.

JOHN CRONHELM
 

The winding of the 3 smaller toroids that you describe is very different from the way it is described in the manual.  Not sure why the difference.
John, vo1jcc.


On Jul 17, 2017, at 2:31 PM, larry.lovell@... [CHINA_QRP] <CHINA_QRP@...> wrote:

 

The difference (main) between Rev C and Rev D is the addition of a speaker mike capability.  Thus, an additional pin is added to the printed circuit board.  The speaker/mike will work with either Rev C or Rev D boards, but you would have to run a wire to the microphone connector (Pin 8) from the speaker connection.

You can download the Rev D manual and other bits of information from my website http://www.larvell.net/Side_Left_B/Download.htm.   (www.qrvtronics.com)

A couple of issues that I have found with power output are as follows.  Make sure that you have wound the toroids properly (easy to miss-count).  See: http://www.larvell.net/Side_Left_B/files/KN-Q7A_App_WindingTheToroid.pdf for additional help.  Make sure that the wire leads have been properly stripped.  With an ohmmeter, you can check the points on the printed circuit boards for the coils making contact.  

The next issue is to check the Transmit Band Pass filter for proper tuning.  If you have a signal generator and an oscilloscope, you can adjust the filter without power to your radio.  I inject the signal at pin 4 on the NE602 and check the signal with the oscilloscope on the 680 ohm resistor.  Adjust the coils for maximum amplitude.

If all that fails, Short Pin 2 and 3 on the NE602 nearest the IF crystal.  This will take the radio out of SSB and you should transmit only the carrier wave.

Check to see where you are loosing the signal.  With an oscilloscope check the amplitude on Pin 4 of the NE602.  Press and release the push-to-talk button on each test.  Next look at the amplitude on the SMD part C3357 on the tab.  The amplitude should have increased.  Next check the amplitude on the Collector of the D882 transistor.  Again, the amplitude should have increased.  Finally, check the amplitude on the 104 cap that leads into the final High Pass Filter section.  You should get a very large voltage swing.

One other thing that I will do just to check the transmit section would be to inject a small signal at the carrier frequency at the 680 ohm resistor.  Try about 50 mV to 100 mV if possible.  Then check each step of the transmitter with an oscilloscope.

You can contact me directly at n7rgw@...
Good luck
Larry


 


Dual Band Modification Now Available for KN-Q7A or CS-Series Radio

n7rgw
 

OK, I am finally ready to announce the Dual Band modification to the KN-Q7A or CS-series radio using the Sandwich VFO.  The modification is easy.

I can provide the Sandwich code modification based on three things:
    1)  Base frequency of original radio (basically the crystal filter chain frequency)
    2)  Base Band operation for example a CS-40 or 40 Meter band operation.
    3)  Additional band you wish to add such as 80 Meters to the 40 Meter base radio.

The cost of the kit includes a PCB for both the Receive and Transmit Frequencies, all parts including the appropriate DIY7 coils.  The introductory price will be $35 USD plus shipping. 

Software will be downloadable from my website once I complete the various permutations of the code.  The software and schematic will be available whether you purchase my kit or not.  However, I support what I sell.

I made a slight error to the first PCB, so you will need to follow the instructions regarding the coils.  I will fix the problem on the next revision of the PCB.  The error does not affect the signal or the filter.

The first run will have limited quantities available.  I have for example 4 kits ready for shipment 80/40 for Base 40 Meter.  I will kit others as the orders come in.

I am finishing the touches of the manual which should be available by the end of the day.

I will add additional photos later.



Re: New Possible Modifications for CS-series (or KN-Q7A) with Sandwich

n7rgw
 

OK, I am finally ready to announce the Dual Band modification to the KN-Q7A or CS-series radio using the Sandwich VFO.  The modification is easy.
I can provide the Sandwich code modification based on three things:
    1)  Base frequency of original radio (basically the crystal filter chain frequency)
    2)  Base Band operation for example a CS-40 or 40 Meter band operation.
    3)  Additional band you wish to add such as 80 Meters to the 40 Meter base radio.

The cost of the kit includes a PCB for both the Receive and Transmit Frequencies, all parts including the appropriate DIY7 coils.  The introductory price will be $35 USD plus shipping. 

Software will be downloadable from my website once I complete the various permutations of the code.  The software and schematic will be available whether you purchase my kit or not.  However, I support what I sell.

I made a slight error to the first PCB, so you will need to follow the instructions regarding the coils.  I will fix the problem on the next revision of the PCB.  The error does not affect the signal or the filter.

The first run will have limited quantities available.  I have for example 4 kits ready for shipment 80/40 for Base 40 Meter.  I will kit others as the orders come in.

I am finishing the touches of the manual which should be available by the end of the day.


Re: KN-Q7A Board rev. 2.2 complete circuit diagram.

n7rgw
 

The difference (main) between Rev C and Rev D is the addition of a speaker mike capability.  Thus, an additional pin is added to the printed circuit board.  The speaker/mike will work with either Rev C or Rev D boards, but you would have to run a wire to the microphone connector (Pin 8) from the speaker connection.
You can download the Rev D manual and other bits of information from my website http://www.larvell.net/Side_Left_B/Download.htm.   (www.qrvtronics.com)

A couple of issues that I have found with power output are as follows.  Make sure that you have wound the toroids properly (easy to miss-count).  See: http://www.larvell.net/Side_Left_B/files/KN-Q7A_App_WindingTheToroid.pdf for additional help.  Make sure that the wire leads have been properly stripped.  With an ohmmeter, you can check the points on the printed circuit boards for the coils making contact.  

The next issue is to check the Transmit Band Pass filter for proper tuning.  If you have a signal generator and an oscilloscope, you can adjust the filter without power to your radio.  I inject the signal at pin 4 on the NE602 and check the signal with the oscilloscope on the 680 ohm resistor.  Adjust the coils for maximum amplitude.

If all that fails, Short Pin 2 and 3 on the NE602 nearest the IF crystal.  This will take the radio out of SSB and you should transmit only the carrier wave.

Check to see where you are loosing the signal.  With an oscilloscope check the amplitude on Pin 4 of the NE602.  Press and release the push-to-talk button on each test.  Next look at the amplitude on the SMD part C3357 on the tab.  The amplitude should have increased.  Next check the amplitude on the Collector of the D882 transistor.  Again, the amplitude should have increased.  Finally, check the amplitude on the 104 cap that leads into the final High Pass Filter section.  You should get a very large voltage swing.

One other thing that I will do just to check the transmit section would be to inject a small signal at the carrier frequency at the 680 ohm resistor.  Try about 50 mV to 100 mV if possible.  Then check each step of the transmitter with an oscilloscope.

You can contact me directly at n7rgw@...
Good luck
Larry


 


Re: KN-Q7A Board rev. 2.2 complete circuit diagram.

Adam Rong
 

Bob,

Please download the full manual package including schematic from:


The 5 pin connector has one additional pin for speaker output, and it should connect to pin 8 of the round mic connector on panel. For ICOM HM-36, it does not have speaker built in, but we do have supply of speaker microphone.

If your ICOM HM-36 is not electret type, the output can be too low to drive enough RF output. You need to talk loudly to your microphone to have higher RF output. If you don’t talk to the microphone, you will get nothing after the first moment of pressing PTT.

Thanks,
Adam

在 2017年7月17日,下午8:44,vk2aor@... [CHINA_QRP] <CHINA_QRP@...> 写道:


Hi Al


New to this group.


A member of my radio club built the above kit and was trying to get it going with the Rev C notes.  He asked me to have look and see if I could get it going.   the Rev C refers to a 4pin MIC connection and Rev D shows the 5 pin MIC connection on the board and he has purchased a speaker /MIC with the kit.   The manual says that there is a complete circuit diagram but I could not find it in the files section or the website.   This would be helpful and would appreciate a copy if anyone can help.


The manual also said that a HM Series Icon mike will work with it.    Once the 5 pin cable to the 8 pin MIC socket was wired correctly  my HM-36 worked for PTT and started to get power output and could see the modulating signal on my CRO, but only 0.5 watts.

Adjusted the bias current to 0.543 Amps and it appeared to increase the power but while holding the mic button down and no modulation the power decreased.   Have I interpreted the instructions correctly?   On my other transceivers on SSB there maybe a quick flicker of power then nothing till there is some modulation.  Also with AM I would be able to see steady output to be able to adjust the transmitter.


  I have a 2 tone battery operated board which I will wire into an 8 pin mic socket with a switch for PTT and see what Happens.   I would be good to have a complete schematic  with the manual for reference and service at a later date.


I appreciate this forum and look forward to some clues.


Bob VK2AOR




KN-Q7A Board rev. 2.2 complete circuit diagram.

Robert Hudson
 

Hi Al


New to this group.


A member of my radio club built the above kit and was trying to get it going with the Rev C notes.  He asked me to have look and see if I could get it going.   the Rev C refers to a 4pin MIC connection and Rev D shows the 5 pin MIC connection on the board and he has purchased a speaker /MIC with the kit.   The manual says that there is a complete circuit diagram but I could not find it in the files section or the website.   This would be helpful and would appreciate a copy if anyone can help.


The manual also said that a HM Series Icon mike will work with it.    Once the 5 pin cable to the 8 pin MIC socket was wired correctly  my HM-36 worked for PTT and started to get power output and could see the modulating signal on my CRO, but only 0.5 watts.

Adjusted the bias current to 0.543 Amps and it appeared to increase the power but while holding the mic button down and no modulation the power decreased.   Have I interpreted the instructions correctly?   On my other transceivers on SSB there maybe a quick flicker of power then nothing till there is some modulation.  Also with AM I would be able to see steady output to be able to adjust the transmitter.


  I have a 2 tone battery operated board which I will wire into an 8 pin mic socket with a switch for PTT and see what Happens.   I would be good to have a complete schematic  with the manual for reference and service at a later date.


I appreciate this forum and look forward to some clues.


Bob VK2AOR


Article for Choc Perf Board

Adam Rong
 

Folks,

I just uploaded a small article about building SSB radio with Choc Perf
Board. I kept MS Word format so that you can feel free to reuse it for
your club or association publications. I have already submitted to
Amateur Radio magazine in Australia as Knobless Wonder is quite well
known there.

http://crkits.com/chocperfboard.doc

Thanks,
Adam


Re: Challenge: Building a BITX on a Perf Board? [2 Attachments]

AA7US
 


---In CHINA_QRP@..., <rongxh@...> wrote :

> Another project in mind is to make a DSB radio with VOX by 3x3 units so it can be used for digital modes like PSK31 or JT65. I have many 14070 crystals on hand.


Now that sounds interesting!

73,

John
AA7US