Reducing harmoncs on a NATO 2000
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Reducing harmoncs on a NATO 2000
Good evening all,
I just thought I'd share a little filter I've added to my NATO 2000 to reduce the harmoncs.
I was given the rig as a scrap chassis so have done quite a lot of work to get this thing going but it has been a great little project.
Having looked at the harmonics, i thought I'd try and reduce them a little as I thought they were still a little too high.
So I built this little filter today and fitted it inside the radio and as you can see from the results, the harmonics have dropped drastically.
I'm super happy with the result!
I just thought I'd share a little filter I've added to my NATO 2000 to reduce the harmoncs.
I was given the rig as a scrap chassis so have done quite a lot of work to get this thing going but it has been a great little project.
Having looked at the harmonics, i thought I'd try and reduce them a little as I thought they were still a little too high.
So I built this little filter today and fitted it inside the radio and as you can see from the results, the harmonics have dropped drastically.
I'm super happy with the result!
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Last edited by HeliJimbo on 02 Mar 2022, 22:20, edited 1 time in total.
- cb4ever104
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Re: Reducing harmoncs on a NATO 2000
Looks nice. Any reduction in output power with it fitted ?
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
- Buick Mackane
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Re: Reducing harmoncs on a NATO 2000
Hi,
Natuarlly there is some loss.
The calculator I used estimated about -0.3 db of which is quite close.
Hope that helps?
- Auldgeek
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Re: Reducing harmoncs on a NATO 2000
Excellent! Well done
Auldgeek - Drew
Winner of IBTL Autumn 23 Edition
I've changed radios so many times, I've forgotten what I have
Winner of IBTL Autumn 23 Edition
I've changed radios so many times, I've forgotten what I have
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Re: Reducing harmoncs on a NATO 2000
Here's all the values if anyone is interested.
The outside capacitors were 100 pF
The inside one was 220 pF
The inductors were 360 nH
For the coils I just used a nanoVNA and a trim tool I had to wrap the wire and I kept wrapping until I got the inductance above.
Initially I used a calculator from M0UKD and got these values.
Diameter 8mm
Length 15mm
Number of turns = 10
The outside capacitors were 100 pF
The inside one was 220 pF
The inductors were 360 nH
For the coils I just used a nanoVNA and a trim tool I had to wrap the wire and I kept wrapping until I got the inductance above.
Initially I used a calculator from M0UKD and got these values.
Diameter 8mm
Length 15mm
Number of turns = 10
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- Auldgeek
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Re: Reducing harmoncs on a NATO 2000
Do you reckon your Nato without the filter, was typical of that board, or did you attempt to remove the harmonics by normal tune-up as per service manual? Just curious.
Auldgeek - Drew
Winner of IBTL Autumn 23 Edition
I've changed radios so many times, I've forgotten what I have
Winner of IBTL Autumn 23 Edition
I've changed radios so many times, I've forgotten what I have
- Otter
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Re: Reducing harmoncs on a NATO 2000
The manual quotes harmonics will be lower than about -53dBc. The radio looks like it was about -45dBc before mods.
"To this day the words Stirling bridge conjour pride in every Scotsman's heart, while to an Englishman those same words conjour literally no feelings at all." - Cunk on Britain S1 E1
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Re: Reducing harmoncs on a NATO 2000
I did the full tune-up as per the service manual and compared to another NATO I had and the harmonics were exactly at the same level.
For the sake of a little work I thoight why not put one in, even if it's just because I can.
:-)
For the sake of a little work I thoight why not put one in, even if it's just because I can.
:-)
- Auldgeek
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Re: Reducing harmoncs on a NATO 2000
Auldgeek - Drew
Winner of IBTL Autumn 23 Edition
I've changed radios so many times, I've forgotten what I have
Winner of IBTL Autumn 23 Edition
I've changed radios so many times, I've forgotten what I have