INPUT TUNING: What I found to be the hot ticket has been the MFJ 259B
antenna analyzer. Remove drive cable from your amp and connect it to the
259, key the amp and adjust the slugs. Just watch the meters as you crank
the slug into resonance.
Others, more astute than myself, will provide the answer to the 10 meter
problem...
At 08:57 PM 8/25/98 -0500, Tom Branch wrote:
>
>Greetings,
>
>Still having fun with my SB-200. Took some time today to look at the input
>VSWR on each band. 40 and 20 meters are 1.0:1, 15 meters ranges from 1.4 to
>1.7:1, 80 meters is over 5:1--seems like an easy adjustment of the input
>tank coils. My plan here is to remove the SB-200 from its case to expose
>the input tank coils. Each one is marked in the book as to the band. I
>think the safe way to do this is to make a slight adjustment, then fire up
>the amp to see what the effect was--slowing getting to where I want it to
>be. Is this the best method?
>
>10 meters acts strange. The output oscillates as does the VSWR--not a fast
>one but noticeable on the power meter. If I drive the amp hard enough the
>relay in the amp will drop out and begin to oscillate as well. Any ideas
>on this one?
>
>TU es 73 de Tom, K4NR
>
>PS Just built the small switching circuit (single NPN, two 1K resisters
>and a diode) that Rich Measures had on his homepage to use the positive 12
>volts from the TS-450 to switch over the SB-200--what a pleasure as I got
>to turn that noisy relay in the TS-450 off. Thanks again Rich...
>
>
>--
>FAQ on WWW: http://www.contesting.com/ampfaq.html
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
>
>
John Wilcox NS1Z
FN44rn
ns1z@agate.net
fon: 207-364-2246
871 Route 120
Rumford, ME 04276-3836
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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