Kenwood TS-520S Question

[Richard Knoppow]

I posted this earlier but realized I sent it as a reply
to another post and not as a new post. On my computer it
does not show up individually so I am sending it again.

I joined the Kenwood list but so far have not received
any replys so I thought I would try here.
I recently bought a TS-520S. Its very clean but has a
problem in transmit: there is no drive on either 160 or 80
meters. The receiver works fine on these bands.
I can see a modification has been made. In the area of
the crystals near the front panel two crystals have been
added and use the RF attenuator switch to change them. I
tried to see if switching made any difference to the drive
but it does not.
I wonder if anyone recognizes this as a common mod for
this transceiver and knows how to undo it. I searched around
for mods but there seem to be a great many. I have an
operating manual from the Kenwood site and a service manual
from another site along with a high-rez schematic (those in
the handbook are unreadable). Eventually, I will trace this
thing down but I was hoping someone would have encountered
this before. I don't see any other signs of surgery on this
thing.
The only other thing I found was that someone had
neatly clipped out one of the wires supplying the fan. Why
anyone would do this is beyond me. I replaced the lead and
the fan works fine.




--
Richard Knoppow
Los Angeles
WB6KBL
***@ix.netcom.com

[Joe]

Richard,

That 2-crystal mod doesn't sound at all familiar. Can you see the
frequency marked on them? Maybe we can deduce their purpose.

A botched mod may explain the lack of drive on 160 and 80. The 520 is
such a nice rig, it makes you wonder why people mess around with them
like that. How clipping the wires to the fan would be considered an
"improvement" by anybody is beyond me!

73,
Joe K9LY

Post by Richard Knoppow
I recently bought a TS-520S. Its very clean but has a
problem in transmit: there is no drive on either 160 or 80
meters. The receiver works fine on these bands.
I can see a modification has been made. In the area of
the crystals near the front panel two crystals have been
added and use the RF attenuator switch to change them. I
tried to see if switching made any difference to the drive
but it does not.
(snip)
The only other thing I found was that someone had
neatly clipped out one of the wires supplying the fan. Why
anyone would do this is beyond me. I replaced the lead and
the fan works fine.

[Dale Parfitt]

Post by Joe
Richard,
That 2-crystal mod doesn't sound at all familiar. Can you see the
frequency marked on them? Maybe we can deduce their purpose.
A botched mod may explain the lack of drive on 160 and 80. The 520 is
such a nice rig, it makes you wonder why people mess around with them
like that. How clipping the wires to the fan would be considered an
"improvement" by anybody is beyond me!
73,
Joe K9LY

I'm with Joe- and the quality of the mods is usually horrible. As for the
fan wire- probably the owner at that time needed a piece of wire that length
anc color.

Dale W4OP

[Richard Knoppow]

Post by Joe
Richard,
That 2-crystal mod doesn't sound at all familiar. Can you
see the
frequency marked on them? Maybe we can deduce their
purpose.
A botched mod may explain the lack of drive on 160 and 80.
The 520 is
such a nice rig, it makes you wonder why people mess
around with them
like that. How clipping the wires to the fan would be
considered an
"improvement" by anybody is beyond me!
73,
Joe K9LY

Snipping here.....

The two crystals are indeed for the 11 meter citizen's
band. They are in the AUX position and the RF attenuator
switch was adapted to switch them. I can't see how these
would affect the other bands but I will remove the mod as
soon as I can figure out how the attenuator was orginally
wired. BTW, both resistors were left on it. From the
schematic this is a dual switch and only one side is
normally used. The modifier (a polite term) put the crystals
on the unused side but disconnected whatever was on the
other. The schematics are difficult for me to read so I will
probably re-draw the significant part.
The curious thing about 160 and 80 is that the unit
works perfectly well in receive. The same crystals and much
of the rest of the vfo circuit is used for both. The
handbook suggests that when one band is bad but the others
work to check the tuning. I think the tuning is for both RX
and TX but, if not, that's probably where the problem lies.
I am having to learn my way around this thing and am
being careful not to change anything until I am fairly
certain I know what I am changing. As always any suggestions
will be much appreciated.


--
Richard Knoppow
Los Angeles
WB6KBL
***@ix.netcom.com

[Steve]

I bought a TS-520S a while back on fleabay and found
it had been modified. Two crystals were changed, but they
were in the 10 meter band. Yup, someone had been using it
on 11 meters! A nice AM xtal filter was installed in the CW
position. The mods were actually well done and easily
reversed.

I wonder if someone was trying to do the same mod to
your '520? Look at the freq of the 'new' crystals, and that
will give you a clue.

Steve

[Richard Knoppow]

Post by Richard Knoppow
I posted this earlier but realized I sent it as a
reply to another post and not as a new post. On my
computer it does not show up individually so I am sending
it again.
I joined the Kenwood list but so far have not received
any replys so I thought I would try here.
I recently bought a TS-520S. Its very clean but has a
problem in transmit: there is no drive on either 160 or 80
meters. The receiver works fine on these bands.
I can see a modification has been made. In the area of
the crystals near the front panel two crystals have been
added and use the RF attenuator switch to change them. I
tried to see if switching made any difference to the drive
but it does not.
I wonder if anyone recognizes this as a common mod for
this transceiver and knows how to undo it. I searched
around
for mods but there seem to be a great many. I have an
operating manual from the Kenwood site and a service
manual
from another site along with a high-rez schematic (those
in
the handbook are unreadable). Eventually, I will trace
this
thing down but I was hoping someone would have encountered
this before. I don't see any other signs of surgery on
this
thing.
The only other thing I found was that someone had
neatly clipped out one of the wires supplying the fan. Why
anyone would do this is beyond me. I replaced the lead and
the fan works fine.
--
Richard Knoppow
Los Angeles
WB6KBL

I got it working. I found that someone had modified it
to get on the 11 meter citizen's band. Two crystals were
added to the Aux position using the antenna attenuator
switch to switch the crystals. I also found a jumper between
two sections of the band switch section on the drive board.
The jumper was what was preventing drive for the 160 and 80
meter bands. Removing it got it working on all bands. I
removed the crystals but the original wiring to the
attenuator switch seems to have been removed. This is not a
big deal but the unit does have a reputation for overloading
on strong signals so I think I will want to restore the
attenuator. Curiously enough the resistors are still on the
switch. This is a two section switch and, in its original
configuration, evedently only one side was used. The
modifier (to use a polite term) used the free side but
disconnected the antenna wiring. From the schematics the
original wiring was apparently a couple of lengths of
shielded wire from somewhere around the "EXT-NOR" antenna
switch to the attenuator switch. If anyone is really
familiar with the inner workings of the TS-520S It would be
helpful to me to know how the original wiring was done and
dressed. Its impossible to see it in the photos in the
downloadable instruction book even though these are pretty
high res pictures. Its just not shown there.
In any case, I can get the thing on the air as it is,
all I need now is a stealth antenna:-)


--
Richard Knoppow
Los Angeles, CA, USA
***@ix.netcom.com

[v***@gmail.com]

HI Richard,

I have a TS520S here that has a 27mhz crystal on the Aux position and covers 27.000 - 27.500 which I assume was a very common mod. I want to remove the 27mhz xtal as it is illegal over here in Australia and for the life of me, I cant find the aux position crystal location. I searched the service manual and it indicates that it should be on board x44-1160 but I cant see any added xtals on there. If you have any insight to where the aux crystal position is on the TS520S, it would be a great time saver.
My direct email is ***@posnav.com.au and would love to hear from you or anyone who has any clues to why I am going blind. haha
Cheers
Brenton
VK3CM

Post by Richard Knoppow
I posted this earlier but realized I sent it as a reply
to another post and not as a new post. On my computer it
does not show up individually so I am sending it again.
I joined the Kenwood list but so far have not received
any replys so I thought I would try here.
I recently bought a TS-520S. Its very clean but has a
problem in transmit: there is no drive on either 160 or 80
meters. The receiver works fine on these bands.
I can see a modification has been made. In the area of
the crystals near the front panel two crystals have been
added and use the RF attenuator switch to change them. I
tried to see if switching made any difference to the drive
but it does not.
I wonder if anyone recognizes this as a common mod for
this transceiver and knows how to undo it. I searched around
for mods but there seem to be a great many. I have an
operating manual from the Kenwood site and a service manual
from another site along with a high-rez schematic (those in
the handbook are unreadable). Eventually, I will trace this
thing down but I was hoping someone would have encountered
this before. I don't see any other signs of surgery on this
thing.
The only other thing I found was that someone had
neatly clipped out one of the wires supplying the fan. Why
anyone would do this is beyond me. I replaced the lead and
the fan works fine.
--
Richard Knoppow
Los Angeles
WB6KBL

[l***@gmail.com]

Hi All,

I've had a TS-520S for some time now and I generally use it on the lower bands. I've noticed that the previous owner has replaced the rock for the 28MHz position to make it work on 27MHz. I have no interest in CB at all, so can someone advise where and what value the correct crystal will be? Also, is there any alignment I need to do to get it up and running?

I just want the rig to be normal!

Cheers,
Les (VK1LH)

[Fred McKenzie]

Post by l***@gmail.com
Hi All,
I've had a TS-520S for some time now and I generally use it on the lower
bands. I've noticed that the previous owner has replaced the rock for the
28MHz position to make it work on 27MHz. I have no interest in CB at all, so
can someone advise where and what value the correct crystal will be? Also, is
there any alignment I need to do to get it up and running?
I just want the rig to be normal!

Les-

Perhaps the TS-520S is not old enough, but at one time 27 MHz was a Ham
band!

According to a copy of the TS-520S owner's manual I found on the web,
the crystal is one of those on "OSC COIL UNIT" (X44-1160-00). It
appears that there is one crystal in a switch position called "AUX" that
could have been installed for CB without sacrificing one of the regular
bands.

The crystals shown for the switch positions are:
X1 10.695 MHz (1.9 MHz Band)
X2 12.395 (3.5)
X3 15.895 (7)
X4 22.895 (14)
X5 29.895 (21)
X6 36.895 (28)
X7 37.395 (28.5)
X8 37.995 (29.1)
AUX (Frequency Not Shown)

I also found the TS-520S service manual. It lists Kenwood part numbers
for its crystals:
X1 10.695 part number L77-0725-15 (1.9 MHz Band)
X2 12.395 part number L77-0141-15 (3.5 MHz Band)
X3 15.895 part number L77-0142-15 (7 MHz Band)
X4 22.895 part number L77-0143-15 (14 MHz Band)
X5 29.895 part number L77-0144-15 (21 MHz Band)
X6 36.895 part number L77-0145-15 (28 MHz A Band)
X7 37.395 part number L77-0146-15 (28 MHz B Band)
X8 37.995 part number L77-0147-15 (28 MHz C Band)

If you can determine which crystal was changed, you may be able to order
the correct one from Kenwood. If not, one of the Crystal Manufacturing
companies may know the parameters for the Kenwood crystal.

Fred
K4DII

[Michael Black]

Post by Fred McKenzie

Post by l***@gmail.com
Hi All,
I've had a TS-520S for some time now and I generally use it on the lower
bands. I've noticed that the previous owner has replaced the rock for the
28MHz position to make it work on 27MHz. I have no interest in CB at all, so
can someone advise where and what value the correct crystal will be? Also, is
there any alignment I need to do to get it up and running?
I just want the rig to be normal!

Les-
Perhaps the TS-520S is not old enough, but at one time 27 MHz was a Ham
band!

It's not old enough. Besides, I dont' think a rig would have 27MHz but
not 10Metres.

Even Canada dropped the 11metre ham band at the end of April 1972 (most of
that band had gone to CB about 1961, but they left a small slice for
hams until 1972). The Yaesu FT-101 came out around 1971, and did include
a 11metre band, so maybe over in Australia or somewhere it still existed at the
time, I can't remember if it wsa there for legal reasons, or to cater to
the illegal CB crowd.

Once past the FT-101, I think 11metres was gone, except for rigs intended
for the CB market but sold as ham rigs.

Post by Fred McKenzie
If you can determine which crystal was changed, you may be able to order
the correct one from Kenwood. If not, one of the Crystal Manufacturing
companies may know the parameters for the Kenwood crystal.

The rig is forty years old, I suspect Kenwood doesn't keep parts from that
far back.

And of course, International Crystal shut down this year, making it that
much harder to get a custom crystal ground. When that news hit a few
months back, there were varying stories about who still custom grinds
crystals.

Michael

[R***@yahoo.com]

Can someone tell me where I can obtain volume control pot for ts520 tnx rocco