Topband: Polarity and Phase

[john battin]

    ----- Original Message ----- 
    From: K8LV1 at aol.com<mailto:K8LV1 at aol.com> 
    To: jbattin at msn.com<mailto:jbattin at msn.com> 
    Sent: Thursday, April 15, 2004 11:51 AM
    Subject: Re: Topband: Polarity and Phase


    John: 
          I just got back in town and took a quick look at this phase controversy. Would you please answer two questions for me. 

          First, what is the controversy really about.

    It is really about how close in phase two receivers have to be for good diversity reception and how that is measured. I challenged one of Tom's (W8JI) measurements and I was wrong. 

          Second, and most important, in your experience with diversity reception, have you detected any clear patterns of behavior that can be summarized? In particular, if enhancements of any type can be obtained, approx. what is their magnitude? Are we talking 1 db or 10db? 

    My conclusions:
     The receivers need to be on the same frequency. The receivers need to have their selectivity, gain, etc matched as close as possible. Phase is not too important if you are listening in stereo and the antennas are wide spaced. In my case, I often listen to a vertical array with one ear and beverages in the other. Most of the time there is an advantage with this diversity reception (almost nothing  "Always Happens" on Top Band).  It is not unusual to have a Q3 signal become Q4 or Q5. If the signals are not fading together (one peaking when the other is down) then it is the most dramatic. 

    73 
    Eric K8LV