Yes but how many times do you need to hear the answer?
Bob W6TR
----- Original Message -----
From: "KD7QAE" <KD7QAE@ARRL.NET>
To: "Bob Maser" <bmaser@tampabay.rr.com>
Sent: Saturday, August 27, 2005 2:08 AM
Subject: Re: [Amps] plate choke
> Perhaps it is boring to you but for new builders (like me) it is quite
> interesting.!
>
> Tomm, KD7QAE
>
> Bob Maser wrote:
>
>>Phil, as usual, you have identified the problem(s) and given the solution,
>>all in one easy paragraph. For those that doubt Phil's recommendation of
>>the RF-3 sold at RF Parts, it costs under $25 and it works great. I
>>installed one of them in my 3CX3000 RF amplifier about a month ago and so
>>far there have been no problems, although I'm sure that I am pushing the
>>envelope as to how much current it can take, but that's another story.
>>
>>Hopefully, Phil's recommendation will end this long and boring thread.
>>
>>Bob Maser W6TR
>>----- Original Message -----
>>From: "Phil Clements" <philc@texascellnet.com>
>>To: <amps@contesting.com>
>>Sent: Friday, August 26, 2005 4:49 PM
>>Subject: Re: [Amps] plate choke
>>
>>
>>
>>>>>>A single-layer choke of up to c. 60uH will exhibit no resonances below
>>>>>>approximately 35MHz, however, larger chokes will.
>>>>>>
>>>>Which frequency?
>>>>
>>>Life was much simpler when we only built 5-band amps years ago. With the
>>>addition of the 160, 60, 30, 17, and 12 meter bands, the choke building
>>>business got more complicated. Chokes that worked great on the five bands
>>>did not have enough L to do a proper job on 160 meters. More turns were
>>>required, which brought resonances into the spectrum below 30 mhz. With
>>>the
>>>additional bands, fewer places were available to "park" the resonances in
>>>a
>>>portion of the spectrum far enough away from any amateur band to avoid
>>>heating/smoke/fire. The folks that make the choke that RF Parts sells and
>>>Ameritron uses in their products produced a good compromise that avoids
>>>having to use two chokes to cover the 10 HF bands. This choke is c. 200
>>>uh,
>>>and the resonances are parked c. 11.5 mhz and 34 mhz. This varies
>>>slightly
>>>with each installation and chassis position. It is reasonably priced. I
>>>keep
>>>a stock here, and have used this choke on several projects with great
>>>success. It can be easily duplicated if desired. Please do not use Teflon
>>>rod as a poisonous gas is emitted when ignited.
>>>
>>>Before this choke was available, I went through several trial and error
>>>scenarios; some ending in disaster. Utilizing this product has been 100%
>>>successful for me in several projects over the years. Just something I
>>>don't
>>>have to worry about when lashing up a new amp.
>>>
>>>(((73)))
>>>Phil Clements, K5PC
>>>
>>>
>>>
>>>
>>>
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>>>Amps mailing list
>>>Amps@contesting.com
>>>http://lists.contesting.com/mailman/listinfo/amps
>>
>>_______________________________________________
>>Amps mailing list
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>>
>>
>>
>
>
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