[Amps] 2010 Handbook

[TexasRF at aol.com]

Now that band switching scheme shows some real innovation! I bet it never  
arced did it? 
 
I once built an amplifier that used a plexiglas disc/cam that pushed  on 
scavenged relay leaf/contacts in a similar manner, one cam per contact.  Ugly 
but worked well. Allowed switching cap A, cap B, cap A+B and so on. Your  
screw driven switches would do that also of coarse.
 
73,
Gerald K5GW
 
 
 
 
 
In a message dated 11/17/2010 7:35:42 A.M. Central Standard Time,  
paul at n1bug.com writes:

That's  true Gerald. :-)

The 1/2 inch wide brass "U" clips on the grid,  cathode, and filament 
were quick enough, but the 6 screws for the clamp  plates to hold the 
tube in place (by means of clamping its screen to the  chassis) took 
most of the time!

Band switching could take almost as  long, with lots of little knobs 
which drove screws, which pushed flexible  fingers of aluminum (!) 
against contacts on the tune and load padder  capacitors, thereby 
grounding one side of them. This in various  combinations was 
required on 40, 80, and 160 due to the way-too-small air  variables used.

Those were the days! Uh..... or  not!

73,
Paul


TexasRF at aol.com wrote:
> Well Paul,  if you used alligator clips for the tube connections you 
> could change  the tube in half the time!
>  
> 73,
> Gerald  K5GW
>  
>  
> In a message dated 11/17/2010  5:19:00 A.M. Central Standard Time, 
> paul at n1bug.com writes:
>  
>     Roger (sub1) wrote:
>       >> 4CX1000A?
>      >
>     > 4.    It uses an oddball socket
> 
>   I once built a successful 160-10m amp around a 4CX1000A with  no
>     socket at all. OK, it took 10 minutes to change  out the tube, but
>     you rarely if ever have to  replace one.
> 
>      >       Maximum frequency for full power is only 110 MHz, but  I
>     believe
>      > it will  operate at 144-147 MHz at reduced ratings and a pair in
>   PP will
>      > easily run more than the  legal limit.
> 
>     I ran a single 4CX1000A at  legal limit on 144 MHz for years, never
>     had any  issue at all with it. These tubes have also been used at 222
>   MHz, though one doesn't see that too often.
>  
>     73
>     -- 
>   Paul, N1BUG
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Paul, N1BUG
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