I had this amp (sb 220) for several years and it had always worked
fine. Moving I put it in storage on my new property and 2 years later
when I set up my new ham station...no more 10 meters. All the other
bands work fine with full power out. Looking at the band selector it
also looks fine not burnt out. The bad thing is I run 10 meters. Any
one have an Idea or have come across this problem....please let me know
with some testing ideas.

Thanks Sam

"Sam" wrote in message
oups.com...
I had this amp (sb 220) for several years and it had always worked
fine. Moving I put it in storage on my new property and 2 years later
when I set up my new ham station...no more 10 meters. All the other
bands work fine with full power out. Looking at the band selector it
also looks fine not burnt out. The bad thing is I run 10 meters. Any
one have an Idea or have come across this problem....please let me know
with some testing ideas.

Thanks Sam


I'm not familiar with the amp, so I will give a guess or two. Though you
know the switch doesn't look "burned" out, what about oxidized, dirty or
slightly pitted to not make contact. How about the wires going to it - any
cold solder joints? Wires broken off? Sounds like something subject to the
"switch". Any components which may have been placed in line - open?

Try "rocking" the switch around the 10 meter position while trying to get
the signal going - see if it makes any attempt to work.

That is as far as I can go with no schematic or knowledge of the amp.

Does your 10 meter antenna work OK with the transceiver alone?
"Sam" wrote in message
oups.com...
I had this amp (sb 220) for several years and it had always worked
fine. Moving I put it in storage on my new property and 2 years later
when I set up my new ham station...no more 10 meters. All the other
bands work fine with full power out. Looking at the band selector it
also looks fine not burnt out. The bad thing is I run 10 meters. Any
one have an Idea or have come across this problem....please let me know
with some testing ideas.

Thanks Sam

"Sam" wrote in message
oups.com...
I had this amp (sb 220) for several years and it had always worked
fine. Moving I put it in storage on my new property and 2 years later
when I set up my new ham station...no more 10 meters. All the other
bands work fine with full power out. Looking at the band selector it
also looks fine not burnt out. The bad thing is I run 10 meters. Any
one have an Idea or have come across this problem....please let me know
with some testing ideas.

Thanks Sam


Start with a NICE CLEAN SB-220 SCHEMATIC DRAWING.
Page 1
http://www.n0ss.net/sb-220_schematic..._21oct2006.pdf

Page 2
http://www.n0ss.net/sb-220_schematic..._21oct2006.pdf

If you have access to CorelDraw v6 or newer and wish to obtain copies of
CDR files for these schematics, please drop N0SS a note, and be sure to
indicate
the version of CorelDraw you are using.

w9gb

On 29 Nov 2006 16:56:20 -0800, "Sam" wrote:

I had this amp (sb 220) for several years and it had always worked
fine. Moving I put it in storage on my new property and 2 years later
when I set up my new ham station...no more 10 meters. All the other
bands work fine with full power out. Looking at the band selector it
also looks fine not burnt out. The bad thing is I run 10 meters. Any
one have an Idea or have come across this problem....please let me know
with some testing ideas.

Thanks Sam


Just about has to be the band switch or the lead from the switch to
the coil tap. Not much else unigue to 10 meters. The band switch is a
known weak point. They can still be found on the internet.

Win, W0LZ

On 29 Nov 2006 16:56:20 -0800, "Sam" wrote:

I had this amp (sb 220) for several years and it had always worked
fine. Moving I put it in storage on my new property and 2 years later
when I set up my new ham station...no more 10 meters. All the other
bands work fine with full power out. Looking at the band selector it
also looks fine not burnt out. The bad thing is I run 10 meters. Any
one have an Idea or have come across this problem....please let me know
with some testing ideas.

Thanks Sam

Aside from what other posters have mentioned, there's another area to
look at:

the tuned input coil circuit for 10 mtrs. This is the tuned network on
the input side of the amp. check its bandswitch contact, the input
coil for continuity, etc.

Doug

Sam, all you have said is it is not working on 10. Could you provide a
little more data?
I will help with a little logic:
Are you getting grid current when you drive it?
If no, then investigate the ten meter grid tuned circuit and bandswitch
(good luck, it is buried behind the front panel.)
If you are getting normal grid current, but zero output, then what about
plate current?
If you are getting tons of plate current but no output THEN you could
suspect the bandswitch.

Rick K2XT

Further info would be helpful:

I'd 1st check 10M VSWR PA Input , between xcvr and amp.
erg

"Sam" wrote in message
oups.com...
I had this amp (sb 220) for several years and it had always worked
fine. Moving I put it in storage on my new property and 2 years later
when I set up my new ham station...no more 10 meters. All the other
bands work fine with full power out. Looking at the band selector it
also looks fine not burnt out. The bad thing is I run 10 meters. Any
one have an Idea or have come across this problem....please let me know
with some testing ideas.

Thanks Sam