I've got a Sony 6500W radio. Even with the cheapest multi-band radios there
were separate oscillator and antenna trimmers for each band. Not so with
this radio! Sony chose to use the same pair of rear mounted trimmers for the
AM and all of the shortwave bands.
What I need to find is a currently available AM only portable radio so I can
remove the tuning capacitor and mount it inside of the 6500W. The purpose of
this whole thing is so I can have a separate tuning capacitor for the AM
loopstick.
The fact that this radio uses the same trimmer pair for the SW ranges is ok,
because since the antenna circuit for these ranges is relatively low Q
tracking error is not a problem. The problem shows up when you are tuning a
loopstick that has a Q of 400+.
Now, if I can find a nice low-profile cap I will be all set. One other thing
about this radio............it is dual conversion on the shortwave ranges
but single conversion on the MW band. It isn't a bad MW performer, though.

Pete

I dont know,Pete.I own a lot of old AM only radios.Some of them are tube
type radios and some of them are transistor radios.Maybe if you can get
ahold of an AM only radio,you can rob/borrow some parts from that AM
only radio,or radios.
cuhulin

On Sat, 7 Jan 2006 12:34:21 -0600, "Pete KE9OA"
wrote:

I've got a Sony 6500W radio. Even with the cheapest multi-band radios there
were separate oscillator and antenna trimmers for each band. Not so with
this radio! Sony chose to use the same pair of rear mounted trimmers for the
AM and all of the shortwave bands.
What I need to find is a currently available AM only portable radio so I can
remove the tuning capacitor and mount it inside of the 6500W. The purpose of
this whole thing is so I can have a separate tuning capacitor for the AM
loopstick.
The fact that this radio uses the same trimmer pair for the SW ranges is ok,
because since the antenna circuit for these ranges is relatively low Q
tracking error is not a problem. The problem shows up when you are tuning a
loopstick that has a Q of 400+.
Now, if I can find a nice low-profile cap I will be all set. One other thing
about this radio............it is dual conversion on the shortwave ranges
but single conversion on the MW band. It isn't a bad MW performer, though.

Pete


I'd look at a car parts junkyard, where you might find an AM-only car
radio for peanuts; or, if you know what you want, just get in touch
with a place like Mouser.com (no minimum $$ on orders), and order the
exact trimmer cap you want.

bob
k5qwg

try ebay for an older AM only radio for a dollar or two. also thrift shops
or junk yards


"Pete KE9OA" wrote in message
. ..
I've got a Sony 6500W radio. Even with the cheapest multi-band radios
there were separate oscillator and antenna trimmers for each band. Not so
with this radio! Sony chose to use the same pair of rear mounted trimmers
for the AM and all of the shortwave bands.
What I need to find is a currently available AM only portable radio so I
can remove the tuning capacitor and mount it inside of the 6500W. The
purpose of this whole thing is so I can have a separate tuning capacitor
for the AM loopstick.
The fact that this radio uses the same trimmer pair for the SW ranges is
ok, because since the antenna circuit for these ranges is relatively low Q
tracking error is not a problem. The problem shows up when you are tuning
a loopstick that has a Q of 400+.
Now, if I can find a nice low-profile cap I will be all set. One other
thing about this radio............it is dual conversion on the shortwave
ranges but single conversion on the MW band. It isn't a bad MW performer,
though.

Pete

old car radios don't use variable capacitors, they vary L not C



"Bob Miller" wrote in message
...
On Sat, 7 Jan 2006 12:34:21 -0600, "Pete KE9OA"
wrote:

I've got a Sony 6500W radio. Even with the cheapest multi-band radios
there
were separate oscillator and antenna trimmers for each band. Not so with
this radio! Sony chose to use the same pair of rear mounted trimmers for
the
AM and all of the shortwave bands.
What I need to find is a currently available AM only portable radio so I
can
remove the tuning capacitor and mount it inside of the 6500W. The purpose
of
this whole thing is so I can have a separate tuning capacitor for the AM
loopstick.
The fact that this radio uses the same trimmer pair for the SW ranges is
ok,
because since the antenna circuit for these ranges is relatively low Q
tracking error is not a problem. The problem shows up when you are tuning
a
loopstick that has a Q of 400+.
Now, if I can find a nice low-profile cap I will be all set. One other
thing
about this radio............it is dual conversion on the shortwave ranges
but single conversion on the MW band. It isn't a bad MW performer, though.

Pete


I'd look at a car parts junkyard, where you might find an AM-only car
radio for peanuts; or, if you know what you want, just get in touch
with a place like Mouser.com (no minimum $$ on orders), and order the
exact trimmer cap you want.

bob
k5qwg

Bob Miller wrote:
On Sat, 7 Jan 2006 12:34:21 -0600, "Pete KE9OA"
wrote:


I've got a Sony 6500W radio. Even with the cheapest multi-band radios there
were separate oscillator and antenna trimmers for each band. Not so with
this radio! Sony chose to use the same pair of rear mounted trimmers for the
AM and all of the shortwave bands.
What I need to find is a currently available AM only portable radio so I can
remove the tuning capacitor and mount it inside of the 6500W. The purpose of
this whole thing is so I can have a separate tuning capacitor for the AM
loopstick.
The fact that this radio uses the same trimmer pair for the SW ranges is ok,
because since the antenna circuit for these ranges is relatively low Q
tracking error is not a problem. The problem shows up when you are tuning a
loopstick that has a Q of 400+.
Now, if I can find a nice low-profile cap I will be all set. One other thing
about this radio............it is dual conversion on the shortwave ranges
but single conversion on the MW band. It isn't a bad MW performer, though.

Pete



I'd look at a car parts junkyard, where you might find an AM-only car
radio for peanuts; or, if you know what you want, just get in touch
with a place like Mouser.com (no minimum $$ on orders), and order the
exact trimmer cap you want.

bob
k5qwg

I think Pete is looking for the 'main' tuning capacitor from an AM
radio. Analog car radios generally use inductive tuning (variable
permability coil) so they don't have a tuning capacitor.