GM Billy, In reading back over my post, I did not find a mistake but rather a sentence that was written poorly and might be interpreted two ways; one right, the other would be wrong. Is this the mist
Not quite. Bandpass filters can only kill out of band noise -- that is, a 20M bandpass filter passes ALL 20M signals, regardless of where they come from, but will effectively prevent its own noise fr
Yes, you guys are all correct and I was wrong. I dunno what I was thinking. The transmitter's broadband noise will indeed go through the bandpass filter because it is also actually transmitting on th
The usual practice is this: * TX on, say, 14 MHz, transmits through a 14 MHz bandpass filter, which attenuates the TX noise on 21 MHz. * RX on, say, 21 MHz, receives through a 21 MHz bandpass filter,
STOP - I changed my mind! (hi) I don't think I was wrong, after all. Let's be specific now. STN. 1 is a radio with broadband noise operating on 40m. STN. 2 is a K3 operating on 20m. STN. 3 is an Orio
We might consider the work of W7GLT (SK), Bill Lieske, INTERMOD CONTROL, and this piece http://urgentcomm.com/mag/radio_intermod_getting_upper . Appropriate band pass filtering of each transmitter/re
Hi Rick, Nope ... Re-read what the others have posted, band pass filters are wide bandwidth filters. Wide band width filters CAN NOT reduce in-band narrow "crud" ... they simply cannot by design. Now
Excellent post, Billy. 73, Jim K9YC _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec
Thanks Billy, like always, excellent technical data. A couple of points. The 40dB is a published spec from Dunestar. They "claim" : - Insertion: typical 0.5-,7db, - Rejection: typical 40db band-to-ba
Rick, go to http://www.arcticpeak.com/radiopages/intermodulationproducts.htm and plug in 14020, 21020, and 28020 in as the frequencies of the three radios in your example. Look at the odd order resul
Sweet. I like that program. Thanks Gary. I think most people know this goes on. It's just difficult to calculate this stuff yourself. What is still little known is how bad broadband noise can be at m