[Amps] Peter Dahl / Harbach SB-220 transformer

[Gudguyham at aol.com]

RR about the indexing, I often wondered why there was no mention of that in 
 the manual.  The Heath switch does not have that snap action indexing like 
 some of the better switches. 
 
 
In a message dated 6/11/2010 9:04:57 P.M. Eastern Daylight Time,  
km1h at jeremy.mv.com writes:


----- Original Message ----- 
From: Gudguyham at aol.com
To:  km1h at jeremy.mv.com ; jim.thom at telus.net ; amps at contesting.com
Sent: Friday,  June 11, 2010 7:02 PM
Subject: Re: [Amps] Peter Dahl / Harbach SB-220  transformer




In a message dated 6/11/2010 9:20:21 A.M.  Eastern Daylight Time, 
km1h at jeremy.mv.com writes:
I guess Jim doesnt  understand that more RF places more stress on an already
marginal  bandswitch Lou to say nothing about increased gain can result  in
instability as proven in many amps.

Some like to go for the most  meter wiggle and the heck with reliability(-;

Carl
KM1H

Carl,  I would be the first one to agree that the band switch in the SB-220 
is  marginal for the total power that a pair of 3-500's can produce.  I  
suppose the thought process by the designers was that since I KWDC input  
was 
the "law" and about 600 watts out being the norm, the band switch was  
fine. 
Moving forward to today's law everyone was kicking the power output  up and 
the band switches were failing.  I would say that about 7 out  of 10 of the 
amps I gut for 6 have a band switch issue with one or more  contacts. 
Usually 10 meter contact.  Sometimes 10 and 15.   Although Denny cut 
corners 
here and there, he did supply a much better  band switch in the Dentron and 
AS amps.  Drake also had a very good  band switch, rarely did I ever see a 
bad one.  The bigger Ameritron  amps have a good band switch also.  If you 
want to go for that "meter  wiggle" you had better build up for it.  Just 
like the days of drag  racing, MO power, bigger and more HD clutch and 
gears, 
wider tires  traction, bars etc etc. Lou


Agree Lou, the biggest problem with the  220 is the switch indexing, you 
can 
see that the blown ones barely have  the rotor touching the contact. A 
couple 
of years ago I bought 200  contacts from Electroswitch and am now running 
low; the rebuilt switches  go as fast as I can do them.

Dont get me going on drag racing, Im back  into it in the vintage classes 
for 
the past several years.This may be the  last  season.

Carl
KM1H