K2/100 AM (MW) Broadcast Intermods on 80m - Partial Conclusions

[walter renner]

I found some strong intermod products from AM (medium
wave) broadcast stations on and around 80m when using
a large inverted L and low-pass L-network antenna tuner

Hi Steve, Regarding your post on AM broadcast stations producing intermod
products.
I have been have similar experience with my K2/100 on both 160 and 80m using
and 250 ft
center fed dipole that is fed with ladder line and using an L-network tuner
allowing multi band operation.
If I use my home brew T-match tuner the intermod is not  detectable, but
becomes a problem when the L-network tuner is put back in line.
I downloaded articles form ARRL web site and found information on BCB
High-Pass Filters.
>From that information I was able to build a filter that would handle 100-150
watts RF
and placed it in-line ahead of the K2/100. My results have been very
rewarding and even gave
added benefits, that allowed the KAT100 to work on frequencies that it would
not work
properly before.
Placing an 50 ohm dummy load outside of the filter, shows the filter to be
transparent at
all frequencies above 160m.
There are also High-Pass filters available commercially that allow you to TX
thru them.


73 Kurt - K0ARO
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Wilhelm-3]

Kurt,

Interesting observation - the RF on your antenna from the BC station could
have had an effect on the KAT100 wattmeter in its measurement of reverse
power and was 'fooled' into thinking that signal from the BC station was
reverse power (it is likely much more complicated than that, but the
principles remain) - that situation could lead to incorrect tuning.

Wattmeters are not frequency selective, they just detect whatever is on the
coax.

73,
Don W3FPR

> -----Original Message-----
> ...
 >From that information I was able to build a filter that would
> handle 100-150
> watts RF
> and placed it in-line ahead of the K2/100. My results have been very
> rewarding and even gave
> added benefits, that allowed the KAT100 to work on frequencies
> that it would
> not work
> properly before.
>

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com