[CQ-Contest] 419 band pass filters..... can a heverivierdutycoilbe installed ??

[Keith Dutson]

The W3NQN filters seem to be superior to the ICE and Dunestar filters.
However, I am not aware of a compact model that covers all HF bands as is
often a requirement for DXpeditions.

73, Keith NM5G

-----Original Message-----
From: Tim Duffy K3LR [mailto:k3lr at k3lr.com] 
Sent: Saturday, March 24, 2007 12:49 AM
To: Jukka Klemola
Cc: 'Keith Dutson'; CQ-Contest at contesting.com
Subject: Re: [CQ-Contest] 419 band pass filters..... can a
heverivierdutycoilbe installed ??

I am surprised that no one has commented that the W3NQN TX bandpass filters
handle 200 watts without problem The components inside do not get warm, the
through loss is less and the adjacent band rejection is much better.

I tried to use ICE filters when I started in Multi Multi over 15 years ago.
After several failures I asked W3NQN to design better filters. I still have
serial #001 for each band. No failures of any sort with over 310,000 QSOs!
They are now distributed by Array Solutions.

73!
Tim K3LR


Jukka Klemola wrote:

> The error is current.
> Use multiple smaller parallel capacitors .. or use better caps.
>
> World does develop.
> There are better capacitors available than the brown silver-micas.
> Yep - they were the state of the art in 1900's.
>
> Hi.
> Could not resist writing that in a Friday manner.
>
> Keep on having FUN !
>
> Tuning the ICE 10m filters takes either tweaking the lead lengths or 
> coils.
> Maybe selecting caps of few pF up/down will help, too.
> 10m filters are not very easy to tune.
>
> I have beefed up my 40m ICE that was fried by OI2HQ team a few years 
> back .. Brits fried it. I replaced the toroids with air wound coils.
> The re-furbished filter is better than new!
> 80-160m filters' toroid coils cannot be replaced by air-wounds.
>
> 73,
> Jukka OH6Li
>
> ...
> >My 419A's are rated at 200 watts.
> >
> >During a DXpedition to VP8 (Falklands), the 10M section acted up 
> >(VSWR
> went
> >to 5) when a tuner was placed between it and a vertical antenna with
> high
> >VSWR.  At the time I thought the unit might be bad so swapped it with 
> >another 419A from the second radio running a different band.  After a
> short
> >period of time it too went to high VSWR.  Later, back at home, I
> contacted
> >ICE and they sent replacement caps for the 10M section for both units.
> >
> >I decided to beef up the 10M section in one of the units by doubling
> the >cap voltage ratings through use of multiple caps.  This did not 
> work.  I >could not get the bandpass frequency to adjust properly for 
> 10M.
> ...
> >
> >73, Keith NM5G
>
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