There's quite a few RF doorknob caps available from Russian sources as
found on the big auction site. Usually available in qty of 3 to 6 pcs
and reasonably priced. Now one may have to find space to replace the
disk ceramics. I've fried a few disk ceramics when trying to load the
80M antenna on 160M. A robust cap is well worthwhile.
I've replaced all of the disk ceramic caps in my 238 tuner with the
Russian doorknobs and my SWR drift no longer takes place. I also
replaced those in the Centurion amp. The Johnson Thunderbolt amp is
next for a cap replacement.
73
Bob, K4TAX
> It all depends on what you are using it for. The door knob is a ceramic
> cap. If the use is to parallel the loading cap, then the high voltage is
> not needed. A 1000-1500VDC disk ceramic would be more than adequate. If
> you are concerned about current, then you parallel a few caps to increase
> the current carrying capacity. Three 100pF at 1000VDC caps in parallel
> would make an excellent replacement for the hard to find and expensive
> door
> knob style caps. But, if you have a lot of money to burn, look around
> for a
> NOS silver plated door knob cap. They will probably cost you $25-30 each
> and of course you will want to buy several to have a few spares. ;-)
> Jerry W5JH
> "building something without experimenting is just solder practice"
>
>
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Rodney
> Sent: Thursday, April 11, 2013 4:29 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Fw: Need Caps for Titan II Please
>
> Theirs is a lot difference in a ceramic cap that a door knob cap.
>
> -----Original Message-----
> From: Jerry Haigwood
> Sent: Thursday, April 11, 2013 5:17 PM
> To: 'Discussion of Ten-Tec Equipment'
> Subject: Re: [TenTec] Fw: Need Caps for Titan II Please
>
> Mouser.com will have them a lot cheaper! A 330pF ceramic cap at 6KV only
> costs 73 cents!
> Jerry W5JH
> "building something without experimenting is just solder practice"
>
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of
> k3miy@csonline.net
> Sent: Thursday, April 11, 2013 11:54 AM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Fw: Need Caps for Titan II Please
>
> Bob and others
>
> On pg 43 of the latest RF Parts catalog, there are 300 PF\7.5KV caps for
> less than 20 bucks.
>
> ron
> K3MIY
>
> Quoting Cecil <chacuff@cableone.net>:
>
>> I would start at RF parts...
>>
>> They normally keep a decent supply...
>>
>> Cecil
>> K5DL
>>
>> Sent from my iPad
>>
>> On Apr 11, 2013, at 9:53 AM, "Bob Good" <k4bg@planters.net> wrote:
>>
>> >
>> >
>> > From: Bob Good
>> > Sent: Tuesday, April 09, 2013 15:26
>> > To: Tentec@contesting.com ; Amp Reflector
>> > Subject: Need Caps for Titan II Please
>> >
>> > I own a T-T Model 416 Titan II Amp and having a problem. It started
>> > with
>> an burning arc located at the bottom of the 160 / 80 Meter coil at the
>> junction of the 1/4 inch tubing coil. It carboned the bottom of the
>> coil form. I removed the one chassis mount and reconnected the two
>> coils soldering the junction. I have not a clue as to what caused the
> problem.
>> All functional parameters seemed fine. HV without RF drive, no arc.
>> start applying power and buzzzzz and stinky smoke. In the process of
>> my clumsy attempt at repair I assume I moved two of the ceramic
>> loading caps to where they arced to the screw post on the tuning
>> variable cap resulting in another stinky arc which apparently cooked
>> the caps. When I cleared the caps by folding them back towards the PC
> board, I have no arc but no output either.
>> I hope the only damage is the two caps which are C-6 and C-8 on the
>> Load capacitor shunt board each 320 pf. A call to Paul at T-T
>> produced no
> joy.
>> They do not have the c
>> ap
>> > s. Therefore.... does anyone have a couple of suitable caps I
>> > might
>> purchase or information as to where to go to find them? Any
>> additional comments would also be much appreciated. Thanks for
>> reading
> and your help.
>> (All info correct on QRZ) Regards, Bob K4BG.
>> > _______________________________________________
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>> > TenTec@contesting.com
>> > http://lists.contesting.com/mailman/listinfo/tentec
>> _______________________________________________
>> TenTec mailing list
>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>>
>
>
>
>
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