[Amps] 2010 Handbook

[Carl]

I like the switch used in the Johnson Thunderbolt II aka Tempo 2000.

The fiberglass plate was attached to the end of the large coil and populated 
with heavy duty contacts and wiper (similar to B&W tank coil)and with real 
long arc paths. It was not a shorting switch.  The fiberglass shaft went 
thru the center of the coil as did the copper strap connections. The one I 
worked on last year was a one owner and had seen a long, heavily used, and 
trouble free life until the PS let loose.

Carl
KM1H


----- Original Message ----- 
From: <TexasRF at aol.com>
To: <paul at n1bug.com>
Cc: <amps at contesting.com>
Sent: Wednesday, November 17, 2010 9:38 AM
Subject: Re: [Amps] 2010 Handbook


> 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
>>     Aurora Sentry:  http://www.aurorasentry.com
>>     Piscataquis ARC:  http://www.k1pq.org
>>     N1BUG:  http://www.n1bug.com
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>
> --
> Paul, N1BUG
> Aurora Sentry: http://www.aurorasentry.com
> Piscataquis  ARC: http://www.k1pq.org
> N1BUG:  http://www.n1bug.com
>
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