[CQ-Contest] Filters

[Mario, S56A]

I always considered mica caps appropriate for HF!  Still use WW-II Dublier 
ones.

DL2NBU was lucky with some old porcelain caps.  I know isolation materials 
improved lately.

73 de Mario, S56A

----- Original Message ----- 
From: "W0UN -- John Brosnahan" <shr at swtexas.net>
To: "Mario, S56A" <s56a at bit.si>; <cq-contest at contesting.com>
Sent: 13. junij 2006 14:17
Subject: Re: [CQ-Contest] Filters


> At 01:21 AM 6/13/2006, Mario, S56A wrote:
>>W0UN: And at no time did any capacitors fail the 200 watt test -- or even 
>>get very warm.
>>
>>I guess you were lucky!  I made W3NQN filters with a big VU mica caps for 
>>2 kV and they all failed on 7 MHz and above.
>>Manufacturer sent us new batch for free but they are not tested yet. 
>>DL2NBU specifies VAR power ratings required.
>
>
> Mario,
>
> With all due respect I think it had nothing to do with luck.  Ed designed 
> the filters
> specially using the referenced capacitors BECAUSE they would handle the
> power.  Ed was VERY insistent that these were the right capacitors to use. 
> You
> make substitutions at your own risk.
>
> --John  W0UN
>
>
>
>
>>Simple ICE filter configuration should survive most abuses but 21/28 MHz 
>>isolation is not good enough for SO2R.
>>
>>Please note that BPF info is available in ON4UN book on low bands.
>>
>>73 de Mario, S56A
>>
>>
>>
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