[TenTec] Replacment cw filter

[Rick - NJ0IP / DJ0IP]

Neal, where can I get one of those "Money Trees" you have?

I have built my own 245 (on a breadboard), worked great of course, but I
have also built other cheap audio filter kits and inserted them the same
way.  Worked great too.  Using the original board is a nice-to-have luxury,
but in no way improves the results over the bread-boarded version.

And, like Neal, I also installed a 500 Hz crystal CW filter - I actually
replaced the original 4-pole SSB filter with an XF-9B, 2.4 kHz 8-pole filter
and added the matching 8-pole CW filter.  These were German-made filters.  I
did this in the 1970's.  I definitely would not put that much effort into it
again.

The audio filter will be 80% as effective at less than 5% of the cost.

73
Rick


-----Original Message-----
From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
On Behalf Of Neal Laugman
Sent: Tuesday, December 14, 2010 10:13 AM
To: tentec at contesting.com
Subject: Re: [TenTec] Replacment cw filter

Hi Marty,

Of course there is the alternative to spend as much as the rig is
worth:

http://www.inrad.net/home.php?cat=95

I have Inrad filters in several rigs, and I will probably get a filter
like you are looking for to fit into my Triton IV, too.

http://www.inrad.net/product.php?productid=207&cat=95&page=1

Again, if price is an issue ($125) you can get some cheap-but-
matched crystals from Dan's Small Parts and roll your own. The trick is
having them matched.

MATCHED CRYSTALS BELOW
10 MHZ HC18-U PACKAGE ..... 6/$6.00

4.000 MHZ HC18-U PACKAGE ..... 6/$6.00

9.600 MHZ HC18-U PACKAGE ..... 6/$6.00

8.000 MHZ HC18-U PACKAGE .... 6/$6.00

http://www.danssmallpartsandkits.net/

None of these are the right frequency (9000.5 - 9000.8), but if you look
around the net you can probably find something. HTH.

 
-- 
Neal - NL7VL


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On Tue, 14 Dec 2010 08:53:37 -0600
Marty Hartwell <mhartwe at gmail.com> wrote:

> Hi
> 
> I have asked in the past if anyone has a 245 filter for the 540
> Triton IV and received no
> answers. So I am wondering if anyone in the past has built one on
> Vector board or
> ugly construction and gotten it to work? I am going to RS and see
> what might be available
> to try this, it doesn't look to complicated to me.
> 
> 
> 

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