I have a Kenwood TS-520 sitting on my shelf with a severe VFO problem.
The oscillator frequency intermittently goes unstable, when the
oscillator doesn't cut out completely. The problem will go away if the
tuning knob is bumped a bit, and it seems to be worse at the higher
frequency portion of a band. The radio is unreliable for receiving, and
is not good enough to even think about transmitting.

Without having ripped into the oscillator yet, I am theorizing that
there is a bad connection on the main tuning capacitor. Before I _do_
tear things apart, I wanted to ask:

1. Has anyone out there seen a similar problem? What did it end up being?

2. The oscillator in this rig is well buried, and will take some
careful disassembly to expose. Do any of you have a manual that details
this operation, or have you done it yourself? I'm well capable of doing
it as-is, but if there's a known best way to do it I'd like to start there.

Thanks in advance.

--

Tim Wescott, KG7LI

On Tue, 22 Jun 2004 10:09:12 -0700, Tim Wescott wrote:

I have a Kenwood TS-520 sitting on my shelf with a severe VFO problem.
The oscillator frequency intermittently goes unstable, when the
oscillator doesn't cut out completely. The problem will go away if the
tuning knob is bumped a bit, and it seems to be worse at the higher
frequency portion of a band. The radio is unreliable for receiving, and
is not good enough to even think about transmitting.

Without having ripped into the oscillator yet, I am theorizing that
there is a bad connection on the main tuning capacitor. Before I _do_
tear things apart, I wanted to ask:

1. Has anyone out there seen a similar problem? What did it end up being?

2. The oscillator in this rig is well buried, and will take some
careful disassembly to expose. Do any of you have a manual that details
this operation, or have you done it yourself? I'm well capable of doing
it as-is, but if there's a known best way to do it I'd like to start there.

Thanks in advance.

Hi,,I am assuming that the VFO in the 520 is very similar to the one in the
TS 820 that I used to own.
The frequency counter did not always work in certain spots on the dial, and
of course the radio went dead at the same time.
I finally broke down and removed the VFO from the radio and opened the VFO
up. The main bearing of the tuning capacitor was not always making contact
because of dried up lubricant.
Don't remember for sure what I did to clean it, I used vaseline to
lubricate and reassembled the whole thing..It worked OK after that..
73 de Sieb VE3JUA.

Eskay wrote:

On Tue, 22 Jun 2004 10:09:12 -0700, Tim Wescott wrote:


I have a Kenwood TS-520 sitting on my shelf with a severe VFO problem.
The oscillator frequency intermittently goes unstable, when the
oscillator doesn't cut out completely. The problem will go away if the
tuning knob is bumped a bit, and it seems to be worse at the higher
frequency portion of a band. The radio is unreliable for receiving, and
is not good enough to even think about transmitting.

Without having ripped into the oscillator yet, I am theorizing that
there is a bad connection on the main tuning capacitor. Before I _do_
tear things apart, I wanted to ask:

1. Has anyone out there seen a similar problem? What did it end up being?

2. The oscillator in this rig is well buried, and will take some
careful disassembly to expose. Do any of you have a manual that details
this operation, or have you done it yourself? I'm well capable of doing
it as-is, but if there's a known best way to do it I'd like to start there.

Thanks in advance.


Hi,,I am assuming that the VFO in the 520 is very similar to the one in the
TS 820 that I used to own.
The frequency counter did not always work in certain spots on the dial, and
of course the radio went dead at the same time.
I finally broke down and removed the VFO from the radio and opened the VFO
up. The main bearing of the tuning capacitor was not always making contact
because of dried up lubricant.
Don't remember for sure what I did to clean it, I used vaseline to
lubricate and reassembled the whole thing..It worked OK after that..
73 de Sieb VE3JUA.

That sounds very plausible. I got the radio at a hamfest, and I think I
know why...

Did you have any trouble getting the oscillator out, or was it just a
matter of taking the usual care with such things? On my 520 it looks
like I have to go through a few layers to get to the VFO case.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

hi tim,

do you subscribe to the kenwood reflector?

To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/kenwood

73 ed


Tim wrote:

Eskay wrote:

On Tue, 22 Jun 2004 10:09:12 -0700, Tim Wescott wrote:


I have a Kenwood TS-520 sitting on my shelf with a severe VFO problem.
The oscillator frequency intermittently goes unstable, when the
oscillator doesn't cut out completely. The problem will go away if the
tuning knob is bumped a bit, and it seems to be worse at the higher
frequency portion of a band. The radio is unreliable for receiving, and
is not good enough to even think about transmitting.

Without having ripped into the oscillator yet, I am theorizing that
there is a bad connection on the main tuning capacitor. Before I _do_
tear things apart, I wanted to ask:

1. Has anyone out there seen a similar problem? What did it end up being?

2. The oscillator in this rig is well buried, and will take some
careful disassembly to expose. Do any of you have a manual that details
this operation, or have you done it yourself? I'm well capable of doing
it as-is, but if there's a known best way to do it I'd like to start there.

Thanks in advance.


Hi,,I am assuming that the VFO in the 520 is very similar to the one in the
TS 820 that I used to own.
The frequency counter did not always work in certain spots on the dial, and
of course the radio went dead at the same time.
I finally broke down and removed the VFO from the radio and opened the VFO
up. The main bearing of the tuning capacitor was not always making contact
because of dried up lubricant.
Don't remember for sure what I did to clean it, I used vaseline to
lubricate and reassembled the whole thing..It worked OK after that..
73 de Sieb VE3JUA.

That sounds very plausible. I got the radio at a hamfest, and I think I
know why...

Did you have any trouble getting the oscillator out, or was it just a
matter of taking the usual care with such things? On my 520 it looks
like I have to go through a few layers to get to the VFO case.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

ed wrote:

hi tim,

do you subscribe to the kenwood reflector?

To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/kenwood

73 ed


Tim wrote:


Eskay wrote:


On Tue, 22 Jun 2004 10:09:12 -0700, Tim Wescott wrote:



I have a Kenwood TS-520 sitting on my shelf with a severe VFO problem.
The oscillator frequency intermittently goes unstable, when the
oscillator doesn't cut out completely. The problem will go away if the
tuning knob is bumped a bit, and it seems to be worse at the higher
frequency portion of a band. The radio is unreliable for receiving, and
is not good enough to even think about transmitting.

Without having ripped into the oscillator yet, I am theorizing that
there is a bad connection on the main tuning capacitor. Before I _do_
tear things apart, I wanted to ask:

1. Has anyone out there seen a similar problem? What did it end up being?

2. The oscillator in this rig is well buried, and will take some
careful disassembly to expose. Do any of you have a manual that details
this operation, or have you done it yourself? I'm well capable of doing
it as-is, but if there's a known best way to do it I'd like to start there.

Thanks in advance.


Hi,,I am assuming that the VFO in the 520 is very similar to the one in the
TS 820 that I used to own.
The frequency counter did not always work in certain spots on the dial, and
of course the radio went dead at the same time.
I finally broke down and removed the VFO from the radio and opened the VFO
up. The main bearing of the tuning capacitor was not always making contact
because of dried up lubricant.
Don't remember for sure what I did to clean it, I used vaseline to
lubricate and reassembled the whole thing..It worked OK after that..
73 de Sieb VE3JUA.

That sounds very plausible. I got the radio at a hamfest, and I think I
know why...

Did you have any trouble getting the oscillator out, or was it just a
matter of taking the usual care with such things? On my 520 it looks
like I have to go through a few layers to get to the VFO case.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com


No, but it looks like I should -- even if I'm already in mailing list
overload.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

On Tue, 22 Jun 2004 11:57:49 -0700, Tim Wescott wrote:

Eskay wrote:

On Tue, 22 Jun 2004 10:09:12 -0700, Tim Wescott wrote:


I have a Kenwood TS-520 sitting on my shelf with a severe VFO problem.
The oscillator frequency intermittently goes unstable, when the
oscillator doesn't cut out completely. The problem will go away if the
tuning knob is bumped a bit, and it seems to be worse at the higher
frequency portion of a band. The radio is unreliable for receiving, and
is not good enough to even think about transmitting.

Without having ripped into the oscillator yet, I am theorizing that
there is a bad connection on the main tuning capacitor. Before I _do_
tear things apart, I wanted to ask:

1. Has anyone out there seen a similar problem? What did it end up being?

2. The oscillator in this rig is well buried, and will take some
careful disassembly to expose. Do any of you have a manual that details
this operation, or have you done it yourself? I'm well capable of doing
it as-is, but if there's a known best way to do it I'd like to start there.

Thanks in advance.


Hi,,I am assuming that the VFO in the 520 is very similar to the one in the
TS 820 that I used to own.
The frequency counter did not always work in certain spots on the dial, and
of course the radio went dead at the same time.
I finally broke down and removed the VFO from the radio and opened the VFO
up. The main bearing of the tuning capacitor was not always making contact
because of dried up lubricant.
Don't remember for sure what I did to clean it, I used vaseline to
lubricate and reassembled the whole thing..It worked OK after that..
73 de Sieb VE3JUA.

That sounds very plausible. I got the radio at a hamfest, and I think I
know why...

Did you have any trouble getting the oscillator out, or was it just a
matter of taking the usual care with such things? On my 520 it looks
like I have to go through a few layers to get to the VFO case.

Not a great deal of trouble but be carefull to remember the sequence of
removal..73 de Eskay.

Eskay wrote:

On Tue, 22 Jun 2004 11:57:49 -0700, Tim Wescott wrote:


Eskay wrote:


On Tue, 22 Jun 2004 10:09:12 -0700, Tim Wescott wrote:



I have a Kenwood TS-520 sitting on my shelf with a severe VFO problem.
The oscillator frequency intermittently goes unstable, when the
oscillator doesn't cut out completely. The problem will go away if the
tuning knob is bumped a bit, and it seems to be worse at the higher
frequency portion of a band. The radio is unreliable for receiving, and
is not good enough to even think about transmitting.

Without having ripped into the oscillator yet, I am theorizing that
there is a bad connection on the main tuning capacitor. Before I _do_
tear things apart, I wanted to ask:

1. Has anyone out there seen a similar problem? What did it end up being?

2. The oscillator in this rig is well buried, and will take some
careful disassembly to expose. Do any of you have a manual that details
this operation, or have you done it yourself? I'm well capable of doing
it as-is, but if there's a known best way to do it I'd like to start there.

Thanks in advance.


Hi,,I am assuming that the VFO in the 520 is very similar to the one in the
TS 820 that I used to own.
The frequency counter did not always work in certain spots on the dial, and
of course the radio went dead at the same time.
I finally broke down and removed the VFO from the radio and opened the VFO
up. The main bearing of the tuning capacitor was not always making contact
because of dried up lubricant.
Don't remember for sure what I did to clean it, I used vaseline to
lubricate and reassembled the whole thing..It worked OK after that..
73 de Sieb VE3JUA.

That sounds very plausible. I got the radio at a hamfest, and I think I
know why...

Did you have any trouble getting the oscillator out, or was it just a
matter of taking the usual care with such things? On my 520 it looks
like I have to go through a few layers to get to the VFO case.


Not a great deal of trouble but be carefull to remember the sequence of
removal..73 de Eskay.

With Ed's link to a manual I think I know how to do it -- it _should_
have occurred to me to take the front panel off!

Now I just need to find the time, and if the bearings _are_ dried out
I'll need to decide what to put back in.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com