[HCDX] CRN 4960 Notes; Tx/Rx Intermod Calculator

["Guy Atkins" <dx@xxxxxxxxxxxxx>]

CRN Vanimo was in quite well this morning, and I was surprised to find
threshold audio on the recording as early as 0730 UTC (approx. 1 hour before
Vanimo SS). Their signal rose slowly and steadily, peaking at my local SR
(1215 UTC). Radio Federacion Shuar was a background pest from about
1000-1115, but CRN dominated. CRN was still in at a poor-fair level at 1400.

Wayne Wilson of TE-PNG mentioned that on June 5th he adjusted the audio
processor to sharpen up the modulation of the audio. I definitely think this
has made an improvement. Propagation differences aside, the audio noted on
my June 5-6-7 recordings is crisper than my June 4 recording, particularly
noticeable when the signal is fading in at poor-fair level.

I found the web site for the Australian firm that manufactures CRN's Polar
POD330 Delta antenna, but there are no pictures or specifics about this
model. However, there's an interesting "Interference Intermodulation
Calculator" available for free download:
http://www.polarelec.com.au/downloads.htm  It runs under Windows from its
own folder, and doesn't install anything or modify the Registry. After a few
minutes of study I figured out how to use the software to calculate & verify
the daytime-only intermod/mixing products that occur in my Beverage
antenna's impedance matching transformers from the 50kw MW stations in my
area. (I've verified that the mixing is not happening in the
receivers--multiple Kiwa BCB highpass filters make no difference in the
intermod heard; however, a faraday-shielded primary winding in the Beverage
matcher has greatly reduced the problem on one antenna and totally
eliminated it on my other Beverage.) This nifty program calculates 2nd
through 7th order mixing products, as well as 3-frequency combinations. If
you're having trouble with *receiver* generated mixing products, I think you
can enter your rig's IF frequency(s) to calculate results (enter the IF
frequency as the "R" or "Rx" freq).

Guy Atkins
Puyallup, WA USA

---[Start Commercial]---------------------

World Radio TV Handbook 2004 is out! Only $20.97 through us.

http://www.amazon.com/exec/obidos/ASIN/0823059685/hardcoredxcom

---[End Commercial]-----------------------
________________________________________
Hard-Core-DX mailing list
Hard-Core-DX@xxxxxxxxxxxxxxxx
http://dallas.hard-core-dx.com/mailman/listinfo/hard-core-dx
http://www.hard-core-dx.com/
_______________________________________________

THE INFORMATION IN THIS ARTICLE IS FREE. It may be copied, distributed
and/or modified under the conditions set down in the Design Science License
published by Michael Stutz at http://dsl.org/copyleft/dsl.txt