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I have an MN-2000 that somewhere in its long history, suffered a somewhat
catastrophic event that vaporized one set of the rotating fingers on the band
switch, damaged two of the contact points on the steatite wafer, and cracked
the wafer.

I found this switch which has potential:



The contacts are much like the one in the tuner; however, the rotating part is
different. The band switch in the MN-2000 isn't a traditional rotary switch in
that it doesn't make use of a wiper and, instead, the rotating fingers are like
a rotary shorting bar (for lack of a better way to describe it). Presumably if
you've ever looked at one of these, you know what I'm talking about.

Does anyone have any pointers on how I might go about replacing/repairing this?
The tuner is is in otherwise exceptionally great condition so I'd like to
repair it and use it.

Thanks,
Barry - N4BUQ

I have removed the switch assembly from the tuner and have a question. If I'm
not mistaken, the original switch had 10 fingers, each one contacting 2
contacts at any of the 5 positions. Is that correct? Based on what I can
surmise, that's likely correct but thought I'd check first.

Thanks,
Barry - N4BUQ

I have an MN-2000 that somewhere in its long history, suffered a somewhat
catastrophic event that vaporized one set of the rotating fingers on the band
switch, damaged two of the contact points on the steatite wafer, and cracked
the wafer.

I found this switch which has potential:



The contacts are much like the one in the tuner; however, the rotating part is
different. The band switch in the MN-2000 isn't a traditional rotary switch in
that it doesn't make use of a wiper and, instead, the rotating fingers are like
a rotary shorting bar (for lack of a better way to describe it). Presumably if
you've ever looked at one of these, you know what I'm talking about.

Does anyone have any pointers on how I might go about replacing/repairing this?
The tuner is is in otherwise exceptionally great condition so I'd like to
repair it and use it.

Thanks,
Barry - N4BUQ

Pictures of the switch/cap/coil assembly are here:

/g/DRAKE-RADIO/album?id=301171

Barry - N4BUQ

I have removed the switch assembly from the tuner and have a question. If I'm
not mistaken, the original switch had 10 fingers, each one contacting 2
contacts at any of the 5 positions. Is that correct? Based on what I can
surmise, that's likely correct but thought I'd check first.

Thanks,
Barry - N4BUQ

I have an MN-2000 that somewhere in its long history, suffered a somewhat
catastrophic event that vaporized one set of the rotating fingers on the band
switch, damaged two of the contact points on the steatite wafer, and cracked
the wafer.

I found this switch which has potential:



The contacts are much like the one in the tuner; however, the rotating part is
different. The band switch in the MN-2000 isn't a traditional rotary switch in
that it doesn't make use of a wiper and, instead, the rotating fingers are like
a rotary shorting bar (for lack of a better way to describe it). Presumably if
you've ever looked at one of these, you know what I'm talking about.

Does anyone have any pointers on how I might go about replacing/repairing this?
The tuner is is in otherwise exceptionally great condition so I'd like to
repair it and use it.

Thanks,
Barry - N4BUQ

From: "jerry-KF6VB" <jerry@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Saturday, March 8, 2025 5:01:53 PM
Subject: Re: [DRAKE-RADIO] MN-2000 - Damaged Band Switch

On 2025-03-08 14:39, n4buq wrote:

I'll need to remove the existing tiny rivets and then re-rivet
it.

** Instead of re-riviting the finger, I'd attach it with a screw & nut.
On a job like that, I used fasteners from a little kit meant for fixing
eyeglasses. And Loktite.

The ceramic is fragile. I wouldn't bang on it. Been there, done
that...

- Jerry, KF6VB

On Mar 8, 2025, at 5:16?PM, Joe - W7RKN via groups.io <w7rkn.7@...> wrote:

?A wee (sic) bit more expensive, but..for accuracy: If I am remembering correctly, the wafer switch in the W4 watt meter is the same wafer switch.

Corrections anyone??!!

Joe - WRKN


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of n4buq via groups.io
Subject: Re: [DRAKE-RADIO] MN-2000 - Damaged Band Switch

I have found a switch that will work and be almost exactly like the original:



As part of the process, I will need to remove one of the "fingered" plates and move to a location which is rotated a bit from where it is now. I'll need to remove the existing tiny rivets and then re-rivet it.

I think Centralab used to sell repair kits for things like this which may have included rivets. Does anyone know where small rivets like these can be found? I think a hobby shop might be a good place but not sure. Anyone know?

I think I would be more inclined to use a tiny brass screw and nut. Would be a shame to crack a new section trying to secure a rivet!
Just my .02!!

R
> On Mar 8, 2025, at 5:16?PM, Joe - W7RKN via groups.io <w7rkn.7@...> wrote:
>
> ?A wee (sic) bit more expensive, but..for accuracy: If I am remembering correctly, the wafer switch in the W4 watt meter is the same wafer switch.
>
> Corrections anyone??!!
>
> Joe - WRKN
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf Of n4buq via groups.io
> Subject: Re: [DRAKE-RADIO] MN-2000 - Damaged Band Switch
>
> I have found a switch that will work and be almost exactly like the original:
>
> https://www.ebay.com/itm/226616438192
>
> As part of the process, I will need to remove one of the "fingered" plates and move to a location which is rotated a bit from where it is now. I'll need to remove the existing tiny rivets and then re-rivet it.
>
> I think Centralab used to sell repair kits for things like this which may have included rivets. Does anyone know where small rivets like these can be found? I think a hobby shop might be a good place but not sure. Anyone know?
>
>
>
>
>
>
>

I have used tiny brass hardware for switch repairs.

On Sat, 8 Mar 2025 18:51:29 -0500 (EST)
"n4buq via groups.io" <n4buq@...> wrote:

Yeah, I have some #0-80 nuts and screws. I may use those with some Loktite.

Thanks,
Barry - N4BUQ

--

73

-Jim
NU0C

Pictures of the switch/cap/coil assembly are here:

/g/DRAKE-RADIO/album?id=301171

Barry - N4BUQ

I have removed the switch assembly from the tuner and have a question. If I'm
not mistaken, the original switch had 10 fingers, each one contacting 2
contacts at any of the 5 positions. Is that correct? Based on what I can
surmise, that's likely correct but thought I'd check first.

Thanks,
Barry - N4BUQ

I have an MN-2000 that somewhere in its long history, suffered a somewhat
catastrophic event that vaporized one set of the rotating fingers on the band
switch, damaged two of the contact points on the steatite wafer, and cracked
the wafer.

I found this switch which has potential:



The contacts are much like the one in the tuner; however, the rotating part is
different. The band switch in the MN-2000 isn't a traditional rotary switch in
that it doesn't make use of a wiper and, instead, the rotating fingers are like
a rotary shorting bar (for lack of a better way to describe it). Presumably if
you've ever looked at one of these, you know what I'm talking about.

Does anyone have any pointers on how I might go about replacing/repairing this?
The tuner is is in otherwise exceptionally great condition so I'd like to
repair it and use it.

Thanks,
Barry - N4BUQ

Update:

I finished making the repairs to the Band Switch. New pictures are in the /g/DRAKE-RADIO/album?id=301171 album.

The fingers on the switch I bought were mounted in two sections and the switch needed them all in one contiguous section. I removed one of the sections and re-mounted it using #80 brass screws and stainless-steel nuts with Loctite to make sure those nuts did not work themselves loose. Since the fingers all need to be be connected together, I soldered a heavy-gauge piece of copper wire to both sections. I also needed to remove one switch finger as there were 11 and the switch only uses 10 of them.

The switch I bought also did not have the connection points rotated such that they faced each other in pairs like the original switch was configured. I opted to remove the flat straps from the capacitors and substituted a heavy gauge solid copper wire in a VEE shape that connects two solder points to each capacitor (see pictures). That seems to work well enough.

Getting the "fingers" of the coil reattached was a bit painful. I formed loops of solid copper wire to accept each finger and connect it to two of the solder points on the switch. That was quite tedious due to the limited space but I got it done.

I reassembled the internals and, for fun (since I didn't have a transmitter on the workbench) I connected it to my R390 receiver. I was quite surprised at what a difference that makes matching my 20M inverted VEE in my attic to 80M at the receiver. In my 50+ years as a ham, I've never owned a separate tuner like this and was impressed at the sharpness the tuning provides in that scenario. I intend to drag out the TR-4 and my dummy load and see what that looks like. Of course, since it's a 50-ohm dummy load, the tuner won't have much to do but I thought I'd see what it does there before moving on to using the attic antenna with it. I don't have anything to test it with legal-limit power so I'll have to trust that it will properly handle that much power the way I reconnected the switch.

I really, really like this new "toy"!

Thanks
Barry - N4BUQ

Pictures of the switch/cap/coil assembly are here:

/g/DRAKE-RADIO/album?id=301171

Barry - N4BUQ

I have removed the switch assembly from the tuner and have a question. If I'm
not mistaken, the original switch had 10 fingers, each one contacting 2
contacts at any of the 5 positions. Is that correct? Based on what I can
surmise, that's likely correct but thought I'd check first.

Thanks,
Barry - N4BUQ

I have an MN-2000 that somewhere in its long history, suffered a somewhat
catastrophic event that vaporized one set of the rotating fingers on the band
switch, damaged two of the contact points on the steatite wafer, and cracked
the wafer.

I found this switch which has potential:



The contacts are much like the one in the tuner; however, the rotating part is
different. The band switch in the MN-2000 isn't a traditional rotary switch in
that it doesn't make use of a wiper and, instead, the rotating fingers are like
a rotary shorting bar (for lack of a better way to describe it). Presumably if
you've ever looked at one of these, you know what I'm talking about.

Does anyone have any pointers on how I might go about replacing/repairing this?
The tuner is is in otherwise exceptionally great condition so I'd like to
repair it and use it.

Thanks,
Barry - N4BUQ

From: "John K5MO via groups.io" <johnk5mo@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Monday, March 31, 2025 6:48:28 AM
Subject: Re: [DRAKE-RADIO] MN-2000 - Damaged Band Switch

Well-done, Barry! Your patience is impressive -- I would have put it aside for
parts.



Steve Wedge, W1ES

Time flies like an arrow.? Fruit flies like a banana.

Sent with Proton Mail secure email.

On Sunday, March 30th, 2025 at 10:47 PM, n4buq <n4buq@...> wrote:

Update:

I finished making the repairs to the Band Switch. New pictures are in the
/g/DRAKE-RADIO/album?id=301171 album.

The fingers on the switch I bought were mounted in two sections and the switch
needed them all in one contiguous section. I removed one of the sections and
re-mounted it using #80 brass screws and stainless-steel nuts with Loctite to
make sure those nuts did not work themselves loose. Since the fingers all need
to be be connected together, I soldered a heavy-gauge piece of copper wire to
both sections. I also needed to remove one switch finger as there were 11 and
the switch only uses 10 of them.

The switch I bought also did not have the connection points rotated such that
they faced each other in pairs like the original switch was configured. I opted
to remove the flat straps from the capacitors and substituted a heavy gauge
solid copper wire in a VEE shape that connects two solder points to each
capacitor (see pictures). That seems to work well enough.

Getting the "fingers" of the coil reattached was a bit painful. I formed loops
of solid copper wire to accept each finger and connect it to two of the solder
points on the switch. That was quite tedious due to the limited space but I got
it done.

I reassembled the internals and, for fun (since I didn't have a transmitter on
the workbench) I connected it to my R390 receiver. I was quite surprised at
what a difference that makes matching my 20M inverted VEE in my attic to 80M at
the receiver. In my 50+ years as a ham, I've never owned a separate tuner like
this and was impressed at the sharpness the tuning provides in that scenario. I
intend to drag out the TR-4 and my dummy load and see what that looks like. Of
course, since it's a 50-ohm dummy load, the tuner won't have much to do but I
thought I'd see what it does there before moving on to using the attic antenna
with it. I don't have anything to test it with legal-limit power so I'll have
to trust that it will properly handle that much power the way I reconnected the
switch.

I really, really like this new "toy"!

Thanks
Barry - N4BUQ

Pictures of the switch/cap/coil assembly are here:

/g/DRAKE-RADIO/album?id=301171

Barry - N4BUQ

I have removed the switch assembly from the tuner and have a question. If I'm
not mistaken, the original switch had 10 fingers, each one contacting 2
contacts at any of the 5 positions. Is that correct? Based on what I can
surmise, that's likely correct but thought I'd check first.

Thanks,
Barry - N4BUQ

I have an MN-2000 that somewhere in its long history, suffered a somewhat
catastrophic event that vaporized one set of the rotating fingers on the band
switch, damaged two of the contact points on the steatite wafer, and cracked
the wafer.

I found this switch which has potential:



The contacts are much like the one in the tuner; however, the rotating part is
different. The band switch in the MN-2000 isn't a traditional rotary switch in
that it doesn't make use of a wiper and, instead, the rotating fingers are like
a rotary shorting bar (for lack of a better way to describe it). Presumably if
you've ever looked at one of these, you know what I'm talking about.

Does anyone have any pointers on how I might go about replacing/repairing this?
The tuner is is in otherwise exceptionally great condition so I'd like to
repair it and use it.

Thanks,
Barry - N4BUQ