Amps
[Top] [All Lists]

[AMPS] 2000 ARRL Handbook question

To: <amps@contesting.com>
Subject: [AMPS] 2000 ARRL Handbook question
From: 2@vc.net (measures)
Date: Wed, 2 Aug 2000 09:39:16 -0700
>
>Rich,
>
>Is Wes' raw impedance data for the conventional and
>nichrome suppressors published anywhere? 

?  on Wes' Web site, perhaps.  There is a graph on my Web site that shows 
the differences in Q at 100MHz.   

>Without any
>data to study, this debate ends being more like a
>political battle than scientific inquiry. Seems like
>letting everyone see the impedance data for themselves
>would settle the matter.
>
agreed, Mike.  Conclusions often carry an agenda. 

If you can't find a complete data page, I could try to make a PDF file.  

Cheers

, W4EF...........................................
>
>----- Original Message -----
>From: "measures" <2@vc.net>
>To: "John Simmons" <ka4u@vnet.net>; "AMPS" <amps@contesting.com>
>Sent: Tuesday, August 01, 2000 8:39 PM
>Subject: Re: [AMPS] 2000 ARRL Handbook question
>
>
>>
>> >Rich
>> >on page 13.26
>> >"Some designers use nichrome wire for L(sub)z but there is no credible
>> >evidence of any fundamental difference in performance as a result."
>> >The same statement is in the 99 Handbook.
>>
>> ?  John --  The same statement (by Ehrhorn) was in the '95 Handbook.
>> This was before Wes' tests with the Hewlett Packard Impedance Analyzer.
>> The test evidence showed that a resistance wire suppressor lowers VHF-Q
>> by a bit over 40%.  This is probably a conservative number because we
>> currently use resistance wire that has about 70% more resistance than the
>> wire used in Wes' tests.  However, if resistors were available that had
>> roughly 10nH of L,  And would dissipate at least 30w, an even lower VHF-Q
>> suppressor could be built with copper wire.   Cesiwid Co. told me they
>> could manufacture such resistors.  The asking price for a min. order was
>> about 10 kilobucks.
>>
>> >I don't know if that is what you were referring to but I have seen
>suppresser
>> >resistors cooked and it seem to me the the combination of the  resistance
>and
>> >inductance in the nichrome wire would be a better way to go IMHO.
>>
>> ?  True.  Nichrome can safely operate at dull red heat.  Carbon-comp.
>> resistors can not.  The weak link has always been R-supp.  The problem is
>> in finding a suitable resistor.  Using resistance wire for L-supp helps a
>> bit.    MOF resistors help a bit.  --  Mr. Murphy was right.  Everything
>> is more complicated than it looks.  //.  Congrats to Mr. G. W. Fyler.
>> Congrats to Mr. F. E. Handy.
>>
>> cheers, John
>>
>>
>> >measures wrote:
>> >
>> >> >I will see if i can find it and get back to you.   I t is getting near
>my
>> >> >bed time here on the eastcoast so it may be tomorrow before i can find
>it.
>> >> >John
>> >> >
>> >> Thanks, John, however I already have the info.
>> >>
end


-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


--
FAQ on WWW:               http://www.contesting.com/FAQ/amps
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com


<Prev in Thread] Current Thread [Next in Thread>