Date   
Re: Issue with high SWR on transmit

Fuqua, Bill L
 

Any crystal will oscillate in overtone mode. All crystals can oscillate in series and parallel resonance modes at
fundamental and overtones. The only way the swr would be high with the D4D and not with another source is
that an significant output frequency signal is not what the resonate load expects.
In fact crystals have spurious modes as well, if there is a flaw in it could actually oscillate in an unrelated
frequency. I have seen crystal oscillators jump between modes that are only kHz apart.
   But, you are correct about the low pass filter attenuating an output at the 3rd overtone. I just noticed that the  two
capacitors , C20 and C23, in the filter that are intended to produce notch frequencies in the filter are not in the circuit.
     I think somehow another frequency is being produced that is unintended. And it could be transmitting on the correct frequency and the unintended frequency both.
   Several  other possibilities:
  1. There could be a high frequency applied to the balanced modulator via the audio input. Thus producing a signal way off resonance of the loop antenna.
  2. Q8 may not be shorting the path from the antenna relay into the balanced modulator. Which could offer a significantly high gain feedback path from the output of the balanced modulator thru the RF power amplifier back into the balanced modulator's input.
 A broad spectrum analyzer would be nice. If you have one of these inexpensive nanoVNA's, they can be used as a crude spectrum analyzer. https://groups.io/g/nanovna-users/topic/34079496?20,0,0,0::,,,0,0,0,34079496

This could be useful in seeing what is going on. Just attach a small piece of wire to the input of the nanoVNA as an antenna.

73
Bill wa4lav
Hello again Eric and other possible readers. I received my nanoVNA a couple of weeks ago and I have been doing many tests with it. First I must say my unit came without shields and I added them, but there was no considerable improvement in the base noise level.
groups.io


From: crkits@groups.io <crkits@groups.io> on behalf of Adam Rong via Groups.Io <rongxh@...>
Sent: Monday, November 18, 2019 3:08 AM
To: crkits@groups.io <crkits@groups.io>
Subject: Re: [crkits] Issue with high SWR on transmit
 
Bill,

The crystal is not overtone type. Also the LPF should do the job to filter the 3rd harmonic products if any.

Thanks,
Adam

在 2019年11月18日,下午2:06,Fuqua, Bill L <Wlfuqu00@...> 写道:


Can you receive 20 Meter signals on the D4D?
If not it is possible that the crystal is oscillating at the 3 overtone.
This could produce a VHF signal that would be way off frequency and produce a high
SWR.  If you can copy 20M signals then it is possible that the TX amplifier is oscillating
off frequency producing output power but again off frequency which again would produce
a high SWR with the loop antenna.

73
Bill wa4lav



From: crkits@groups.io <crkits@groups.io> on behalf of Kurt Loken via Groups.Io <kurt.loken@...>
Sent: Sunday, November 17, 2019 11:22 PM
To: crkits@groups.io <crkits@groups.io>
Subject: [crkits] Issue with high SWR on transmit
 

Hello All,

I have a 20M D4D, and I think I may have a problem with it.  

I have been a bit mystified that I have so far only had 1 contact on this thing even though I've been on the air with in for many hours.  I had been thinking it is due to my use of an indoor experimental magloop antenna and the 1W is just isn't making it out of the house.  Yet...what has bothered me is that I have a WSPRlite that only puts out 0.2W and I get picked up all over the US....here is a picture of my spots I got on 20M today with my setup with 0.2 watts on my antenna.  
<Screen Shot 2019-11-17 at 10.00.08 PM.png>


I have good FT8 reception on the D4D...so the receiver part of the system is working like a champ.

I am just getting back into working on radios after a long hiatus and I have have an antenna analyzer, but I actually didn't have a normal SWR meter so that could read my transmissions insitu.  Today I got one.  ...and low and behold...I have horrible SWR readings during transmit when I run the D4D.    I have an Elecraft W1 Power Meter and the SWR pegs out when I transmit.  If I transmit into a dummy load, I get perfect SWR and perfect 1W output. 

I am using a mag loop antenna that is tuned to the 14075 (see pic).  The bandwidth shown is around 40kHz....so unless this thing is way off on the transmit freq or noisy as hell, I should not be seeing huge SWR.

<IMG_4511.jpg>


Any ideas what is going on?  I would be curious what the spectrum my D4D looks like in transmit, but I don't have that test equipment yet.  I'm getting a Red Pitaya very soon...so I will be able to to measure that in the future.  

I don't understand what is going on with the high SWR...any ideas?  

Thanks,

Kurt-AE6UJ

Re: Issue with high SWR on transmit

Adam Rong
 

Bill,

The crystal is not overtone type. Also the LPF should do the job to filter the 3rd harmonic products if any.

Thanks,
Adam

在 2019年11月18日,下午2:06,Fuqua, Bill L <Wlfuqu00@...> 写道:


Can you receive 20 Meter signals on the D4D?
If not it is possible that the crystal is oscillating at the 3 overtone.
This could produce a VHF signal that would be way off frequency and produce a high
SWR.  If you can copy 20M signals then it is possible that the TX amplifier is oscillating
off frequency producing output power but again off frequency which again would produce
a high SWR with the loop antenna.

73
Bill wa4lav



From: crkits@groups.io <crkits@groups.io> on behalf of Kurt Loken via Groups.Io <kurt.loken@...>
Sent: Sunday, November 17, 2019 11:22 PM
To: crkits@groups.io <crkits@groups.io>
Subject: [crkits] Issue with high SWR on transmit
 

Hello All,

I have a 20M D4D, and I think I may have a problem with it.  

I have been a bit mystified that I have so far only had 1 contact on this thing even though I've been on the air with in for many hours.  I had been thinking it is due to my use of an indoor experimental magloop antenna and the 1W is just isn't making it out of the house.  Yet...what has bothered me is that I have a WSPRlite that only puts out 0.2W and I get picked up all over the US....here is a picture of my spots I got on 20M today with my setup with 0.2 watts on my antenna.  
<Screen Shot 2019-11-17 at 10.00.08 PM.png>


I have good FT8 reception on the D4D...so the receiver part of the system is working like a champ.

I am just getting back into working on radios after a long hiatus and I have have an antenna analyzer, but I actually didn't have a normal SWR meter so that could read my transmissions insitu.  Today I got one.  ...and low and behold...I have horrible SWR readings during transmit when I run the D4D.    I have an Elecraft W1 Power Meter and the SWR pegs out when I transmit.  If I transmit into a dummy load, I get perfect SWR and perfect 1W output. 

I am using a mag loop antenna that is tuned to the 14075 (see pic).  The bandwidth shown is around 40kHz....so unless this thing is way off on the transmit freq or noisy as hell, I should not be seeing huge SWR.

<IMG_4511.jpg>


Any ideas what is going on?  I would be curious what the spectrum my D4D looks like in transmit, but I don't have that test equipment yet.  I'm getting a Red Pitaya very soon...so I will be able to to measure that in the future.  

I don't understand what is going on with the high SWR...any ideas?  

Thanks,

Kurt-AE6UJ

Re: Issue with high SWR on transmit

Fuqua, Bill L
 

Can you receive 20 Meter signals on the D4D?
If not it is possible that the crystal is oscillating at the 3 overtone.
This could produce a VHF signal that would be way off frequency and produce a high
SWR.  If you can copy 20M signals then it is possible that the TX amplifier is oscillating
off frequency producing output power but again off frequency which again would produce
a high SWR with the loop antenna.

73
Bill wa4lav



From: crkits@groups.io <crkits@groups.io> on behalf of Kurt Loken via Groups.Io <kurt.loken@...>
Sent: Sunday, November 17, 2019 11:22 PM
To: crkits@groups.io <crkits@groups.io>
Subject: [crkits] Issue with high SWR on transmit
 

Hello All,

I have a 20M D4D, and I think I may have a problem with it.  

I have been a bit mystified that I have so far only had 1 contact on this thing even though I've been on the air with in for many hours.  I had been thinking it is due to my use of an indoor experimental magloop antenna and the 1W is just isn't making it out of the house.  Yet...what has bothered me is that I have a WSPRlite that only puts out 0.2W and I get picked up all over the US....here is a picture of my spots I got on 20M today with my setup with 0.2 watts on my antenna.  
Screen Shot 2019-11-17 at 10.00.08 PM.png

I have good FT8 reception on the D4D...so the receiver part of the system is working like a champ.

I am just getting back into working on radios after a long hiatus and I have have an antenna analyzer, but I actually didn't have a normal SWR meter so that could read my transmissions insitu.  Today I got one.  ...and low and behold...I have horrible SWR readings during transmit when I run the D4D.    I have an Elecraft W1 Power Meter and the SWR pegs out when I transmit.  If I transmit into a dummy load, I get perfect SWR and perfect 1W output. 

I am using a mag loop antenna that is tuned to the 14075 (see pic).  The bandwidth shown is around 40kHz....so unless this thing is way off on the transmit freq or noisy as hell, I should not be seeing huge SWR.

IMG_4511.jpg

Any ideas what is going on?  I would be curious what the spectrum my D4D looks like in transmit, but I don't have that test equipment yet.  I'm getting a Red Pitaya very soon...so I will be able to to measure that in the future.  

I don't understand what is going on with the high SWR...any ideas?  

Thanks,

Kurt-AE6UJ

Re: Issue with high SWR on transmit

Adam Rong
 

Kurt,

I saw the same. Nothing is wrong at your side. I believe the main problem is the wide spectrum caused by IMD. The IMD modification should help, but I will not expect it will be gone.

The D4D is sort of fun kit to test the communication possibilities with such a simple rig. It is not perfect.

Thanks,
Adam

在 2019年11月18日,下午12:22,Kurt Loken <kurt.loken@...> 写道:



Hello All,

I have a 20M D4D, and I think I may have a problem with it.  

I have been a bit mystified that I have so far only had 1 contact on this thing even though I've been on the air with in for many hours.  I had been thinking it is due to my use of an indoor experimental magloop antenna and the 1W is just isn't making it out of the house.  Yet...what has bothered me is that I have a WSPRlite that only puts out 0.2W and I get picked up all over the US....here is a picture of my spots I got on 20M today with my setup with 0.2 watts on my antenna.  
<Screen Shot 2019-11-17 at 10.00.08 PM.png>


I have good FT8 reception on the D4D...so the receiver part of the system is working like a champ.

I am just getting back into working on radios after a long hiatus and I have have an antenna analyzer, but I actually didn't have a normal SWR meter so that could read my transmissions insitu.  Today I got one.  ...and low and behold...I have horrible SWR readings during transmit when I run the D4D.    I have an Elecraft W1 Power Meter and the SWR pegs out when I transmit.  If I transmit into a dummy load, I get perfect SWR and perfect 1W output. 

I am using a mag loop antenna that is tuned to the 14075 (see pic).  The bandwidth shown is around 40kHz....so unless this thing is way off on the transmit freq or noisy as hell, I should not be seeing huge SWR.

<IMG_4511.jpg>


Any ideas what is going on?  I would be curious what the spectrum my D4D looks like in transmit, but I don't have that test equipment yet.  I'm getting a Red Pitaya very soon...so I will be able to to measure that in the future.  

I don't understand what is going on with the high SWR...any ideas?  

Thanks,

Kurt-AE6UJ

Re: Issue with high SWR on transmit

Bryan Brauer
 

Kurt,

I am having almost exactly the same experience; with the 20 meter D4D as well as with the QRPGuys DSB TRXCVR.  I am inclined to believe that double side band is not a good way to go.  I suspect that the signal is just to "dirty" to decode dependably.

I will try a bit more, this time with a resonant dipole. I thought that this radio might be a bit of fun, and I enjoy building kits, but life is to short to muck around with such marginally functioning equipment.  If the dipole does not produce dramatically different results, I will go back to my KX2 for FT8.

Thanks,

Bryan, AI6B

On Sun, Nov 17, 2019 at 8:22 PM Kurt Loken <kurt.loken@...> wrote:

Hello All,

I have a 20M D4D, and I think I may have a problem with it.  

I have been a bit mystified that I have so far only had 1 contact on this thing even though I've been on the air with in for many hours.  I had been thinking it is due to my use of an indoor experimental magloop antenna and the 1W is just isn't making it out of the house.  Yet...what has bothered me is that I have a WSPRlite that only puts out 0.2W and I get picked up all over the US....here is a picture of my spots I got on 20M today with my setup with 0.2 watts on my antenna.  
Screen Shot 2019-11-17 at 10.00.08 PM.png

I have good FT8 reception on the D4D...so the receiver part of the system is working like a champ.

I am just getting back into working on radios after a long hiatus and I have have an antenna analyzer, but I actually didn't have a normal SWR meter so that could read my transmissions insitu.  Today I got one.  ...and low and behold...I have horrible SWR readings during transmit when I run the D4D.    I have an Elecraft W1 Power Meter and the SWR pegs out when I transmit.  If I transmit into a dummy load, I get perfect SWR and perfect 1W output. 

I am using a mag loop antenna that is tuned to the 14075 (see pic).  The bandwidth shown is around 40kHz....so unless this thing is way off on the transmit freq or noisy as hell, I should not be seeing huge SWR.

IMG_4511.jpg

Any ideas what is going on?  I would be curious what the spectrum my D4D looks like in transmit, but I don't have that test equipment yet.  I'm getting a Red Pitaya very soon...so I will be able to to measure that in the future.  

I don't understand what is going on with the high SWR...any ideas?  

Thanks,

Kurt-AE6UJ

Issue with high SWR on transmit

Kurt Loken
 


Hello All,

I have a 20M D4D, and I think I may have a problem with it.  

I have been a bit mystified that I have so far only had 1 contact on this thing even though I've been on the air with in for many hours.  I had been thinking it is due to my use of an indoor experimental magloop antenna and the 1W is just isn't making it out of the house.  Yet...what has bothered me is that I have a WSPRlite that only puts out 0.2W and I get picked up all over the US....here is a picture of my spots I got on 20M today with my setup with 0.2 watts on my antenna.  
Screen Shot 2019-11-17 at 10.00.08 PM.png

I have good FT8 reception on the D4D...so the receiver part of the system is working like a champ.

I am just getting back into working on radios after a long hiatus and I have have an antenna analyzer, but I actually didn't have a normal SWR meter so that could read my transmissions insitu.  Today I got one.  ...and low and behold...I have horrible SWR readings during transmit when I run the D4D.    I have an Elecraft W1 Power Meter and the SWR pegs out when I transmit.  If I transmit into a dummy load, I get perfect SWR and perfect 1W output. 

I am using a mag loop antenna that is tuned to the 14075 (see pic).  The bandwidth shown is around 40kHz....so unless this thing is way off on the transmit freq or noisy as hell, I should not be seeing huge SWR.

IMG_4511.jpg

Any ideas what is going on?  I would be curious what the spectrum my D4D looks like in transmit, but I don't have that test equipment yet.  I'm getting a Red Pitaya very soon...so I will be able to to measure that in the future.  

I don't understand what is going on with the high SWR...any ideas?  

Thanks,

Kurt-AE6UJ

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

Conor Farrell
 

Hi John,

For what it's worth, I built two D4D kits and did effectively no real testing (my bad!): but in both cases the kits worked out perfectly. I just followed the instructions carefully and made sure my solder joints were good. So, like Adam said, if this particular test isn't working as you expect it to, don't worry too much about it.

Conor

On Tue, 12 Nov 2019, 22:44 Adam Rong, <rongxh@...> wrote:
My bad for typo with underline.

When it is working with 15p and 27p, 15p and 27p will give about 15*27/(15+27)p capacitance in parallel and it is lower than the load capacitance of the crystal so it will pull high the frequency. Steve’s way to use a trimmer capacitor is also okay but it will add complexity for alignment as I don’t have to get an exact frequency of 14074, as 200-400 Hz tolerance will be fine.


Thanks,
Adam

在 2019年11月13日,上午6:40,Adam Rong via Groups.Io <rongxh=gmail.com@groups.io> 写道:

How the crystal is pulled:

John,

When it is working with 15p and 27p, 15p and 27p will give about 15*27/(15+27)p capacitance in parallel and it is lower than the load capacitance of the crystal so it will pull high the frequency. Steve’s way to use a trimmer capacitor is also okay but it will add complexity for alignment as I don’t have to get an exact frequency of 14070, as 200-400 Hz tolerance will be fine.

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

Adam Rong
 

My bad for typo with underline.

When it is working with 15p and 27p, 15p and 27p will give about 15*27/(15+27)p capacitance in parallel and it is lower than the load capacitance of the crystal so it will pull high the frequency. Steve’s way to use a trimmer capacitor is also okay but it will add complexity for alignment as I don’t have to get an exact frequency of 14074, as 200-400 Hz tolerance will be fine.


Thanks,
Adam

在 2019年11月13日,上午6:40,Adam Rong via Groups.Io <rongxh@...> 写道:

How the crystal is pulled:

John,

When it is working with 15p and 27p, 15p and 27p will give about 15*27/(15+27)p capacitance in parallel and it is lower than the load capacitance of the crystal so it will pull high the frequency. Steve’s way to use a trimmer capacitor is also okay but it will add complexity for alignment as I don’t have to get an exact frequency of 14070, as 200-400 Hz tolerance will be fine.

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

Adam Rong
 

How the crystal is pulled:

John,

When it is working with 15p and 27p, 15p and 27p will give about 15*27/(15+27)p capacitance in parallel and it is lower than the load capacitance of the crystal so it will pull high the frequency. Steve’s way to use a trimmer capacitor is also okay but it will add complexity for alignment as I don’t have to get an exact frequency of 14070, as 200-400 Hz tolerance will be fine.

As I explained in another thread, the leaked carrier should be received in zero beat way in SSB mode. It is good that you are testing frequency with air coupling. When you receive at 14070, if you receive a high pitch tone in USB mode, the leaked carrier is way higher than 14070. And you cannot receive any at 14074 USB because the carrier is zero beat or on the other side band due to frequency tolerance. You only can receive when it is modulated by audio.

I have sold more than 200 kits already and most of them are 20m version with 14070 crystals. I don’t suspect something is wrong in theory. So if you cannot get through this step, you can go further and actually receive something to verify. Good luck.

Thanks,
Adam

在 2019年11月12日,下午8:30,John <johnk2jhu@...> 写道:


Thank you for getting back to me. My C2 in marked 27J and C3 is marked 150 which we assumed is the 15 as different manufactures have different markings on there parts. Also the way i determined the oscillating frequency was to place a short wire into the antenna input of my FT-817 and placing the D4D board near the radio which resulted in a strong signal at 14.070 and nothing at 14.074.

John K2JHU

On Tue, Nov 12, 2019 at 6:51 AM Adam Rong <rongxh@...> wrote:
John,

Make sure the oscillator capacitors used with 14.070 crystal are 15p and 27p. If not, you are referring to the wrong part list.

Make sure the way to measure the frequency is correct. Your probe will introduce capacitance and it will impact oscillating frequency.

Thanks,
Adam

在 2019年11月12日,下午6:44,John <johnk2jhu@...> 写道:


Adam this did not help. The documentation and schematic say for the 20 meter version of the kit the 14.070 crystal is pulled to the ft8 frequency of 14.074. My unit does not pull the 14.070 crystal frequency to 14.074. There for not working for ft8. What could cause this problem.

John K2JHU...

On Mon, Nov 11, 2019 at 7:05 PM Adam Rong <rongxh@...> wrote:
John,

See this thread.

14.070 crystal is okay for filter with relatively big insertion loss.

Thanks,
Adam

在 2019年11月12日,上午4:32,John <johnk2jhu@...> 写道:


Well I don't understand. They sell lots these kits. Not sure how many are for 20 meters as the 20 meter kits are the only ones that pull the crystal frequency. I think I will contact the owner of crkits and see what he has to say. Thank you very much for your time.

John K2JHU...

On Mon, Nov 11, 2019 at 3:26 PM Steven Weber <steve.kd1jv@...> wrote:

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

John
 

Adam I hope you can forgive me but after checking the part placement for these two capacitors at least a dozen times I just noticed I have C2 and C3 swapped. I have to go out soon but when I retire I will change them and retest. I will let you know what happens. 

John K2JHU...

On Tue, Nov 12, 2019 at 6:51 AM Adam Rong <rongxh@...> wrote:
John,

Make sure the oscillator capacitors used with 14.070 crystal are 15p and 27p. If not, you are referring to the wrong part list.

Make sure the way to measure the frequency is correct. Your probe will introduce capacitance and it will impact oscillating frequency.

Thanks,
Adam

在 2019年11月12日,下午6:44,John <johnk2jhu@...> 写道:


Adam this did not help. The documentation and schematic say for the 20 meter version of the kit the 14.070 crystal is pulled to the ft8 frequency of 14.074. My unit does not pull the 14.070 crystal frequency to 14.074. There for not working for ft8. What could cause this problem.

John K2JHU...

On Mon, Nov 11, 2019 at 7:05 PM Adam Rong <rongxh@...> wrote:
John,

See this thread.

14.070 crystal is okay for filter with relatively big insertion loss.

Thanks,
Adam

在 2019年11月12日,上午4:32,John <johnk2jhu@...> 写道:


Well I don't understand. They sell lots these kits. Not sure how many are for 20 meters as the 20 meter kits are the only ones that pull the crystal frequency. I think I will contact the owner of crkits and see what he has to say. Thank you very much for your time.

John K2JHU...

On Mon, Nov 11, 2019 at 3:26 PM Steven Weber <steve.kd1jv@...> wrote:

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

John
 

my mistake. C2 is the 150 and C3 the 27.
John K2JHU...

On Tue, Nov 12, 2019 at 7:30 AM John via Groups.Io <johnk2jhu=gmail.com@groups.io> wrote:
Thank you for getting back to me. My C2 in marked 27J and C3 is marked 150 which we assumed is the 15 as different manufactures have different markings on there parts. Also the way i determined the oscillating frequency was to place a short wire into the antenna input of my FT-817 and placing the D4D board near the radio which resulted in a strong signal at 14.070 and nothing at 14.074.

John K2JHU

On Tue, Nov 12, 2019 at 6:51 AM Adam Rong <rongxh@...> wrote:
John,

Make sure the oscillator capacitors used with 14.070 crystal are 15p and 27p. If not, you are referring to the wrong part list.

Make sure the way to measure the frequency is correct. Your probe will introduce capacitance and it will impact oscillating frequency.

Thanks,
Adam

在 2019年11月12日,下午6:44,John <johnk2jhu@...> 写道:


Adam this did not help. The documentation and schematic say for the 20 meter version of the kit the 14.070 crystal is pulled to the ft8 frequency of 14.074. My unit does not pull the 14.070 crystal frequency to 14.074. There for not working for ft8. What could cause this problem.

John K2JHU...

On Mon, Nov 11, 2019 at 7:05 PM Adam Rong <rongxh@...> wrote:
John,

See this thread.

14.070 crystal is okay for filter with relatively big insertion loss.

Thanks,
Adam

在 2019年11月12日,上午4:32,John <johnk2jhu@...> 写道:


Well I don't understand. They sell lots these kits. Not sure how many are for 20 meters as the 20 meter kits are the only ones that pull the crystal frequency. I think I will contact the owner of crkits and see what he has to say. Thank you very much for your time.

John K2JHU...

On Mon, Nov 11, 2019 at 3:26 PM Steven Weber <steve.kd1jv@...> wrote:

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

John
 

Thank you for getting back to me. My C2 in marked 27J and C3 is marked 150 which we assumed is the 15 as different manufactures have different markings on there parts. Also the way i determined the oscillating frequency was to place a short wire into the antenna input of my FT-817 and placing the D4D board near the radio which resulted in a strong signal at 14.070 and nothing at 14.074.

John K2JHU


On Tue, Nov 12, 2019 at 6:51 AM Adam Rong <rongxh@...> wrote:
John,

Make sure the oscillator capacitors used with 14.070 crystal are 15p and 27p. If not, you are referring to the wrong part list.

Make sure the way to measure the frequency is correct. Your probe will introduce capacitance and it will impact oscillating frequency.

Thanks,
Adam

在 2019年11月12日,下午6:44,John <johnk2jhu@...> 写道:


Adam this did not help. The documentation and schematic say for the 20 meter version of the kit the 14.070 crystal is pulled to the ft8 frequency of 14.074. My unit does not pull the 14.070 crystal frequency to 14.074. There for not working for ft8. What could cause this problem.

John K2JHU...

On Mon, Nov 11, 2019 at 7:05 PM Adam Rong <rongxh@...> wrote:
John,

See this thread.

14.070 crystal is okay for filter with relatively big insertion loss.

Thanks,
Adam

在 2019年11月12日,上午4:32,John <johnk2jhu@...> 写道:


Well I don't understand. They sell lots these kits. Not sure how many are for 20 meters as the 20 meter kits are the only ones that pull the crystal frequency. I think I will contact the owner of crkits and see what he has to say. Thank you very much for your time.

John K2JHU...

On Mon, Nov 11, 2019 at 3:26 PM Steven Weber <steve.kd1jv@...> wrote:

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

Adam Rong
 

John,

Make sure the oscillator capacitors used with 14.070 crystal are 15p and 27p. If not, you are referring to the wrong part list.

Make sure the way to measure the frequency is correct. Your probe will introduce capacitance and it will impact oscillating frequency.

Thanks,
Adam

在 2019年11月12日,下午6:44,John <johnk2jhu@...> 写道:


Adam this did not help. The documentation and schematic say for the 20 meter version of the kit the 14.070 crystal is pulled to the ft8 frequency of 14.074. My unit does not pull the 14.070 crystal frequency to 14.074. There for not working for ft8. What could cause this problem.

John K2JHU...

On Mon, Nov 11, 2019 at 7:05 PM Adam Rong <rongxh@...> wrote:
John,

See this thread.

14.070 crystal is okay for filter with relatively big insertion loss.

Thanks,
Adam

在 2019年11月12日,上午4:32,John <johnk2jhu@...> 写道:


Well I don't understand. They sell lots these kits. Not sure how many are for 20 meters as the 20 meter kits are the only ones that pull the crystal frequency. I think I will contact the owner of crkits and see what he has to say. Thank you very much for your time.

John K2JHU...

On Mon, Nov 11, 2019 at 3:26 PM Steven Weber <steve.kd1jv@...> wrote:

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

John
 

Adam this did not help. The documentation and schematic say for the 20 meter version of the kit the 14.070 crystal is pulled to the ft8 frequency of 14.074. My unit does not pull the 14.070 crystal frequency to 14.074. There for not working for ft8. What could cause this problem.

John K2JHU...

On Mon, Nov 11, 2019 at 7:05 PM Adam Rong <rongxh@...> wrote:
John,

See this thread.

14.070 crystal is okay for filter with relatively big insertion loss.

Thanks,
Adam

在 2019年11月12日,上午4:32,John <johnk2jhu@...> 写道:


Well I don't understand. They sell lots these kits. Not sure how many are for 20 meters as the 20 meter kits are the only ones that pull the crystal frequency. I think I will contact the owner of crkits and see what he has to say. Thank you very much for your time.

John K2JHU...

On Mon, Nov 11, 2019 at 3:26 PM Steven Weber <steve.kd1jv@...> wrote:

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

Adam Rong
 

John,

See this thread.

14.070 crystal is okay for filter with relatively big insertion loss.

Thanks,
Adam

在 2019年11月12日,上午4:32,John <johnk2jhu@...> 写道:


Well I don't understand. They sell lots these kits. Not sure how many are for 20 meters as the 20 meter kits are the only ones that pull the crystal frequency. I think I will contact the owner of crkits and see what he has to say. Thank you very much for your time.

John K2JHU...

On Mon, Nov 11, 2019 at 3:26 PM Steven Weber <steve.kd1jv@...> wrote:

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

John
 

Well I don't understand. They sell lots these kits. Not sure how many are for 20 meters as the 20 meter kits are the only ones that pull the crystal frequency. I think I will contact the owner of crkits and see what he has to say. Thank you very much for your time.

John K2JHU...

On Mon, Nov 11, 2019 at 3:26 PM Steven Weber <steve.kd1jv@...> wrote:

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

Steven Weber
 

Then your out of luck. You can probably pull the oscillator crystal up 4 kHz with a series trimmer, or at least get it in the ball park. That’s about the limit you can go and retain stability.

 

But you’ll be way off center pass of the crystal in the receiver leg and there’s no good way to change that. The receiver will be exceptionally deaf. A L/C tuned circuit could be substituted for the crystal.

 

KD1JV  

 

 

Both crystals say 14.070

 

K2jhu

 

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

John
 

Both crystals say 14.070

K2jhu

On Mon, Nov 11, 2019 at 1:57 PM Steven Weber <steve.kd1jv@...> wrote:

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

Steven Weber
 

What frequency is the crystal cut for?

KD1JV

 

 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.

There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

 

John K2JHU...

 

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...

 

 

Re: 14.070.0 not pulling to 14.074.0 for the 20 meter DSB

John
 

OK I understand what you are saying. The problem I am having is for the 20 meter D4D kit from crkits.
There are 2 caps, one from pin 7 of the NE602 to ground and one going between pins 6 and 7 and one side of the crystal with the other side of the crystal being grounded. The signal I have is strong but not on 14.074.00

John K2JHU...

On Mon, Nov 11, 2019 at 1:36 PM Steven Weber <steve.kd1jv@...> wrote:

Capacitive loading lowers the crystal frequency, which are typically the two caps on the SA602/612 pins 6 and 7.  But if you have a 14.070 crystal but really want to be on 14.074, you need to put a capacitor in series with the  crystal to rise it’s frequency. This is best done with a trimmer cap, a 30pfd trimmer cap would likely do the trick.

 

Steve KD1JV

 

Hi all. Hoping someone can advise me what causes the pulling of the 14.070.0 crystal to 14.074.0 In step 3 of the manual it states by adding a wire to the antenna termanual of your transceiver and placing the DSB board near the wire you can zero beat to confirm the frequency. The zero beat approach works fine except my unit in on 14.070.0 the crystal frequency, not the pulled 14.074.0. I don't know what actually pulls the frequency so if anyone can help me with this I truly would appreciate it. Thanks for your time.

 

John K2JHU...