[Amps] Peter Dahl / Harbach SB-220 transformer

[Roger]

On 6/11/2010 7:02 PM, Gudguyham at aol.com wrote:
>
> 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
>    

Yup, that lightened flywheel or pressure plate could take the throttle 
pedal right out from under you foot...if you were lucky.  Saw one not 
only do that but right on out through the dashboard and a couple hundred 
feet in the air along with other associated parts.

I like having the capability for overhead and no worry at normal power.

73

Roger (K8RI)
>
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