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I picked up a Daiwa CNA-2002 2.kw mechanical auto tuner at a hamfest recently.
I was told by the seller that the tuner needed work, so I kind of new what I was getting into.
?
When I hook the tuner up, and attempt to have it auto tune it does tune according to the meter on the tuner.
The problem is when the tuner says the reflected power is 1.5:1 or less and stops, the actual swr, as measured by the radio and my external SWR / power meter, is infinite.
If I manually stop the tuner from tuning when it (the tuner) shows the highest reflected power, then my radio and external meter show an SWR of 1.5:1 or lower.
The forward power on the meter does not work.
?
Can anyone think of what may be causing this?
I have looked inside the tuner, and it does not look like anything has been rewired or replaced.
?
Thanks.
Jason
KG7LXJ
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Stupid question… did you hook it up backwards? Just asking? Ted Duskes
VA2TED
PH: 514 739 8723
TXT: 514 709 8723
FAX: 438 239 9654
I picked up a Daiwa CNA-2002 mechanical auto tuner at a hamfest recently.
I was told by the seller that the tuner needed work, so I kind of new what I was getting into.
?
When I hook the tuner up, and attempt to have it auto tune it does tune according to the meter on the tuner.
The problem is when the tuner says the reflected power is 1.5:1 or less and stops, the actual swr, as measured by the radio and my external SWR / power meter, is infinite.
If I manually stop the tuner from tuning when it (the tuner) shows the highest reflected power, then my radio and external meter show an SWR of 1.5:1 or lower.
The forward power on the meter does not work.
?
Can anyone think of what may be causing this?
I have looked inside the tuner, and it does not look like anything has been rewired or replaced.
?
Thanks.
Jason
KG7LXJ
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I'm not sure how I could hook it up backwards?
On Sun, Feb 23, 2025 at 4:35?PM Ted Duskes - VA2TED via <ted.duskes= [email protected]> wrote: Stupid question… did you hook it up backwards? Just asking? Ted Duskes
VA2TED
PH: 514 739 8723
TXT: 514 709 8723
FAX: 438 239 9654
I picked up a Daiwa CNA-2002 mechanical auto tuner at a hamfest recently.
I was told by the seller that the tuner needed work, so I kind of new what I was getting into.
?
When I hook the tuner up, and attempt to have it auto tune it does tune according to the meter on the tuner.
The problem is when the tuner says the reflected power is 1.5:1 or less and stops, the actual swr, as measured by the radio and my external SWR / power meter, is infinite.
If I manually stop the tuner from tuning when it (the tuner) shows the highest reflected power, then my radio and external meter show an SWR of 1.5:1 or lower.
The forward power on the meter does not work.
?
Can anyone think of what may be causing this?
I have looked inside the tuner, and it does not look like anything has been rewired or replaced.
?
Thanks.
Jason
KG7LXJ
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Jason . . . On Sun, 23 Feb 2025 16:30:40 -0800, "Jason - KG7L via groups.io" <zorlockk@...> wrote: Can anyone think of what may be causing this? I have looked inside the tuner, and it does not look like anything has been rewired or replaced. I picked up an Alinco auto tuner that was said to need some work. I got the manual for it, followed the directions for making adjustments, and it works like new. If you don't have one, get a manual for it. See if there is an adjustment inside that can be made to get it working right. Donald KX8K ---------------------------------------------------- Some ham radio groups you may be interested in: /g/ICOM /g/Ham-Antennas/g/HamRadioHelp /g/Baofeng/g/CHIRP
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Transceiver to antenna and antenna to tr socket. It is possible. ? I have done that… With all the wires we have behind our equipment, not too hard to do it. I looked at the back of the cna2002 and I admit doing it backwards is not probable, but i learned that with wiring, anything is possible. Ted Duskes
VA2TED
PH: 514 739 8723
TXT: 514 709 8723
FAX: 438 239 9654
I'm not sure how I could hook it up backwards?
On Sun, Feb 23, 2025 at 4:35?PM Ted Duskes - VA2TED via <ted.duskes= [email protected]> wrote: Stupid question… did you hook it up backwards? Just asking? Ted Duskes
VA2TED
PH: 514 739 8723
TXT: 514 709 8723
FAX: 438 239 9654
I picked up a Daiwa CNA-2002 mechanical auto tuner at a hamfest recently.
I was told by the seller that the tuner needed work, so I kind of new what I was getting into.
?
When I hook the tuner up, and attempt to have it auto tune it does tune according to the meter on the tuner.
The problem is when the tuner says the reflected power is 1.5:1 or less and stops, the actual swr, as measured by the radio and my external SWR / power meter, is infinite.
If I manually stop the tuner from tuning when it (the tuner) shows the highest reflected power, then my radio and external meter show an SWR of 1.5:1 or lower.
The forward power on the meter does not work.
?
Can anyone think of what may be causing this?
I have looked inside the tuner, and it does not look like anything has been rewired or replaced.
?
Thanks.
Jason
KG7LXJ
|
Assuming it is connected properly, I would check the diodes in the SWR bridge. Looks like they are 1N60s, and a bad diode there would explain why the FWD isn’t registering on the meter, and why the auto tune is confused. -Doug, W6DSR ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Jason - KG7L via groups.io
Sent: Sunday, February 23, 2025 16:31
To: [email protected]
Subject: [Antenna-Tuners] Daiwa CNA-2002 auto tuner ? I picked up a Daiwa CNA-2002 2.kw mechanical auto tuner at a hamfest recently. I was told by the seller that the tuner needed work, so I kind of new what I was getting into. When I hook the tuner up, and attempt to have it auto tune it does tune according to the meter on the tuner. The problem is when the tuner says the reflected power is 1.5:1 or less and stops, the actual swr, as measured by the radio and my external SWR / power meter, is infinite. If I manually stop the tuner from tuning when it (the tuner) shows the highest reflected power, then my radio and external meter show an SWR of 1.5:1 or lower. The forward power on the meter does not work. Can anyone think of what may be causing this? I have looked inside the tuner, and it does not look like anything has been rewired or replaced.
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I'm confused about it being a "ethnically auto" tune?
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Show quoted text
On Mon, 24 Feb 2025 at 18:48, Epignathus <doug@...> wrote: Assuming it is connected properly, I would check the diodes in the SWR bridge. Looks like they are 1N60s, and a bad diode there would explain why the FWD isn’t registering on the meter, and why the auto tune is confused. -Doug, W6DSR ? From: [email protected] [mailto:[email protected]] On Behalf Of Jason - KG7L via groups.io
Sent: Sunday, February 23, 2025 16:31
To: [email protected]
Subject: [Antenna-Tuners] Daiwa CNA-2002 auto tuner ? I picked up a Daiwa CNA-2002 2.kw mechanical auto tuner at a hamfest recently. I was told by the seller that the tuner needed work, so I kind of new what I was getting into. When I hook the tuner up, and attempt to have it auto tune it does tune according to the meter on the tuner. The problem is when the tuner says the reflected power is 1.5:1 or less and stops, the actual swr, as measured by the radio and my external SWR / power meter, is infinite. If I manually stop the tuner from tuning when it (the tuner) shows the highest reflected power, then my radio and external meter show an SWR of 1.5:1 or lower. The forward power on the meter does not work. Can anyone think of what may be causing this? I have looked inside the tuner, and it does not look like anything has been rewired or replaced.
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Damned predictive text!
Try "mechanically auto".......
On Mon, 24 Feb 2025 at 18:59, bobsayers2000 via groups.io <bobsayers2000@...> wrote: I'm confused about it being a "ethnically auto" tune? On Mon, 24 Feb 2025 at 18:48, Epignathus <doug@...> wrote: Assuming it is connected properly, I would check the diodes in the SWR bridge. Looks like they are 1N60s, and a bad diode there would explain why the FWD isn’t registering on the meter, and why the auto tune is confused. -Doug, W6DSR ? From: [email protected] [mailto:[email protected]] On Behalf Of Jason - KG7L via groups.io
Sent: Sunday, February 23, 2025 16:31
To: [email protected]
Subject: [Antenna-Tuners] Daiwa CNA-2002 auto tuner ? I picked up a Daiwa CNA-2002 2.kw mechanical auto tuner at a hamfest recently. I was told by the seller that the tuner needed work, so I kind of new what I was getting into. When I hook the tuner up, and attempt to have it auto tune it does tune according to the meter on the tuner. The problem is when the tuner says the reflected power is 1.5:1 or less and stops, the actual swr, as measured by the radio and my external SWR / power meter, is infinite. If I manually stop the tuner from tuning when it (the tuner) shows the highest reflected power, then my radio and external meter show an SWR of 1.5:1 or lower. The forward power on the meter does not work. Can anyone think of what may be causing this? I have looked inside the tuner, and it does not look like anything has been rewired or replaced.
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Check all the RF diodes, especially those in the forward sense.? Use a DMM in the diode position to check both forward and reverse voltage.? For the diode(s) reverse should be nearly infinite while the forward should be between 0.4 and 0.8 vdc.?
Dave - W?LEV?
On Mon, Feb 24, 2025 at 12:32?AM Jason - KG7L via <zorlockk= [email protected]> wrote: I picked up a Daiwa CNA-2002 mechanical auto tuner at a hamfest recently.
I was told by the seller that the tuner needed work, so I kind of new what I was getting into.
?
When I hook the tuner up, and attempt to have it auto tune it does tune according to the meter on the tuner.
The problem is when the tuner says the reflected power is 1.5:1 or less and stops, the actual swr, as measured by the radio and my external SWR / power meter, is infinite.
If I manually stop the tuner from tuning when it (the tuner) shows the highest reflected power, then my radio and external meter show an SWR of 1.5:1 or lower.
The forward power on the meter does not work.
?
Can anyone think of what may be causing this?
I have looked inside the tuner, and it does not look like anything has been rewired or replaced.
?
Thanks.
Jason
KG7LXJ
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Please join me.
Dave - W?LEV
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Curious... did your solve the problem?
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Ted, I did. I found out how I could hook it up backwards. Lol
There were a few other problems as well. Cold solder joints, bad diode.?
The pdf manual online is horrible quality, but Daiwa sent me a good clear pdf of the schematic which was super helpful.
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Turned out the forward power not showing was a bent needle in the movement. Fixed that, and the destroyed the movement for the reflected power. MAD FACE!.
I found an old cn-520 on ebay that uses the same meter that sound be here tomorrow. I will replace both needles and the cover. The meter cover on the 2002 is chipped/ broken in a couple places.?
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This is a first gen auto tuner. It is run by a DC motor. When you push and release the operation button the motor turns plastic gears connected to the caps and inductor.?
This is a pic of the cna-1001. Same route if tuner, but handles less power.
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Ted Duskes - VA2TED
Epignathus