Thanks to everyone who replied to my mail. The power supply was my principal
concern and I now have some useful tips on how to bring the old girl back to
life again.
Thanks once again.
73
Graham G8ewt
-----Original Message-----
From: Chuck Curran [mailto:ccurran@wi.rr.com]
Sent: 06 July 2009 02:14
To: G8EWT@diacon.co.uk
Subject: RE: [Amps] Yaesu FL-2100Z
Hello Graham:
I understood from you posting that the FL-2100Z has not been used in at
least 10 years. If that is the case, I would be very concerned about the
condition of the electrolytic capacitors. I found a copy of the FL-2100Z
schematic on BAMA. It shows 6 electrolytics in the high voltage supply and
another 7 in other areas. The electrolytics are going to be a real
concern, at least it would be for me, if I was trying to bring this amp back
to life.
You should first look at each and every one of the electrolytics. Check for
any signs of failure or leakage of electrolyte. Look at both ends of the
caps, for leakage. Any visual sign of that white pasty stuff squirting out
of the pressure relief blister on the end cap is a sign of " I died a while
ago---". Just replace them all, or, see below.
If no signs of a previous failure are found, continue here. My second
suggestion would be to get an auto-transformer, and plug the amp into the
auto transformer set at 10% of line voltage. Turn the amp on and let it
"cook" at 10% input voltage for 24 hours. The goal is to allow the
electrolyte in the capacitors to reform and start working properly again.
After 24 hours at 10% voltage input, raise the AC input voltage to20%. Let
it run for another 5 hours. Every 8 hours, raise the input in steps of 10%,
until you reach normal line input of 100%. From the first hour to the last,
just pray you do not hear a loud pop!
The pop is the last dying breath of an electrolytic in your linear.
Many electrolytics can be reformed, if you take your time. I do it with
them out of the circuit, and each one is in series with a 100K resistor. I
do not raise the DC input voltage until the cap voltage is within 1-2% of
the DC power supply voltage being used to "reform" the caps. Go slow, do
not rush it!!!!
I think the above is the approach to conserve expenses. If the amp is
something you want to have as a reliable piece of equipment, I would spend
the money and replace 100% of the electrolytics right now.
Best Regards and Good Luck!!
Chuck W9POU
Cedarburg, WI USA
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of G8EWT
Sent: Sunday, July 05, 2009 2:30 PM
To: amps@contesting.com
Subject: [Amps] Yaesu FL-2100Z
Can't be sure that this mail was forwarded by my server so am resending it.
Graham G8EWT
From: G8EWT [mailto:G8EWT@diacon.co.uk]
Sent: 05 July 2009 14:38
To: 'amps@contesting.com'
Subject: Yaesu FL-2100Z
I've just been given an FL-2100Z that's lain unused for at least 10 years.
I've had the covers off and the inside seems surprisingly clean and I'm
unable to see any evidence of damage.
My question is what checks/reconditioning would you do before powering up
the amplifier?
Many thanks
73
Graham G8EWT
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