[Premium-Rx] Ten-Tec RX-340 - Amateur Use

[Carcia, Francis A HS]

The tighter the filter the more you need a good diplexer. Easy to build
though.

-----Original Message-----
From: John Miles [mailto:jmiles at pop.net]
Sent: Tuesday, February 08, 2005 12:55 PM
To: premium-rx at ml.skirrow.org
Subject: RE: [Premium-Rx] Ten-Tec RX-340 - Amateur Use


Keep in mind, too, that simply adding a 3-kHz filter after the first mixer
does not guarantee improved real-world performance.  You may also need a
diplexer after the first mixer to present a 50-ohm (or whatever) load across
the board.  A mixer that isn't terminated in a *broadband* load won't be all
it can be in the IMD department.

-- john KE5FX

>
> First, as I mentioned, making a narrow filter at high frequencies is not
> trivial.  You think paying $100 for a typical 9 MHz xtal filter is bad...
> try and price a 40.455 3 KHz xtal filter!
>
> And I can think of many receivers costing much more than the TenTec that
> don't have them either.
>
> > Tell me then, why don't all high end HF rigs have this capability?  The
> > Ten Tec 340 roofing filter mod looked pretty straight forward and
> > inexpensive (using a KIWA 4 kc filter).  Others have done this
> mod and are
> > happy, but I wasn't due to the loss of fidelity.  Guy Atkins and I had
> > problems when we tried added a switch to the mod.  Somewhere along the
> > line we lost a lot of signal strength, which was not the case if the
> > filter was wired in permanently.  I've been wondering about
> this problem
> > for quite a while.  I don't understand why a $4k receiver (ie the 340)
> > wouldn't have such a capability.  I re-iterate again that the
> Ten Tec is a
> > bit of a dog on MW in it's unaltered state.......Walt.
> >
>


_______________________________________________

Premium-Rx Mailing List
To Post: premium-rx at ml.skirrow.org
For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx
Visit the Website: http://kahuna.sdsu.edu/~mechtron/PremRxPage/