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REPAIR AND RESTORATION OF THE SR-2000
5
WDØGOF 3/7/20014
1. SR-2000 INITIAL INSPECTION AND TESTING.
SO YOU JUST GOT AN SR-2000 FROM E-BAY OR SOMEONE THAT
SAID “IT WORKED FINE THE LAST TIME I TURNED IT ON”. NOW
WHERE DO YOU START? THE FOLLOWING PROCESS HAS
EVOLVED OVER YEARS OF REFURBISHING THE SR SERIES
EQUIPMENT. IT SHOULD BE FOLLOWED IN THE ORDER IT IS
WRITTEN. THIS PROCEDURE IS DESIGNED TO PROGRESS IN AN
ORDERLY MANNER TO MINIMIZE RUNNING IN CIRCLES. YOU
MUST
HAVE THE MINIMUM OF TEST EQUIPMENT LISTED TO
PROPERLY REHAB OR REPAIR THIS EQUIPMENT. BE AWARE THIS
IS NOT SOMETHING THAT WILL BE ACCOMPLISHED WITH GREAT
SPEED. THE AVERAGE TIME TO COMPLETION IS AROUND 80
HOURS. SOME HAVE TAKEN AS MUCH AS 200 HOURS, SOME AS
FEW AS 20 HOURS.
1-1. VISUAL AND MECHANICAL INSPECTION
Complete chassis cleaning and mechanical inspection are always advised. Cleaning of the controls, rotary
switches and the relays is of particular importance. Look closely for broken or burned components. Check the
rotation of the controls and mechanical stops of the main tuning dial (Section 8-8-A in the manual). Try to
eliminate the mechanical problem first. If you are going to upgrade to a higher production run complete those
upgrades before you start the electrical tests. If your rig is paired with an HA-20 disconnect it and install a
jumper from pin 2 to pin 10 of J2. Test pin 10, it should be grounded.
1-2. RECAPPING;
There are only 2 capacitors that are considered
must replace
components. They are C146, 25 uf/25v and C147,
2 X 30 uf/350v. Capacitor C147 carries a heavy current load. Therefore the ESR rating of its replacement is
important. They should have an ESR rating of 1.0 ohm or less. ESR’s less than 0.3 ohm are available. This is
not a place to save money. C147 is a dual cap. There are sources for this capacitor,
but
be careful. Some
manufactures of these parts use inexpensive low quality parts. Don't buy from suppliers who will not quote or
guarantee the ESR rating. Very low ESR individual capacitors are readily available. So replacing the dual cap
with two capacitors under the chassis is sometimes a better solution. Generally speaking shotgun replacement of
the paper caps is not recommended at this stage of refurbishment.
1-3. AFTER MARKET MODIFICATIONS
If you find any modifications, re-wirings or added components evaluate the mods closely. The best on line
source for proper modifications is k9axn.com. If the authenticity of the mods cannot be verified remove them
and return the rig to the original configuration.