K5CM FMT 0100 UTC April 21, 2017    Thursday evening in Oklahoma

Conditions seemed about average for this springtime FMT. Jeff W3JW had an especially good 20 meter reading, almost hitting the nail on the head. Most of the 20 meter readings were biased low which is what you might expect with the sun just setting.  Some are at a disadvantage because they are in the skip zone of the 20 meter signal, never the less, stations like K5RKS, and WB0LXZ managed to find enough backscatter or what ever to make sub 0.5Hz 20 meter readings. Also, W2TX and K4IVF had very close 80 meter readings. Thanks to all the participants.  73, Connie, K5CM

Thanks to Steve, WA9VNJ for processing the raw excel file into the following results  












Transmitting equipment used by K5CM for this FMT:

A HP Z3801 GPS frequency source clocks a HP-3336B. The output is feed to a 10 db transistor amp which drives a 12BY7 / pair 6146. Then to a MLA-2500 running about 400 watts.  There are no mixers or any device in the chain of amplifiers that might impact the accuracy of the GPS frequency source.  As a reality check,  I periodically log the frequency source against WWV and other GPS referenced sources.  I monitor each transmission with a completely separate receive system to look for any instability or short term drift. 

I typically see considerably less than 1 mHz difference at 10 Mhz when comparing  two Z3801's or a Z3801 and a Thunderbolt, over a 10 to 10,000 second period. 



160 - Vertical

 80 - Dipole.  (favors West, North, East)

 40 - Standard Dipole hanging between two 80 foot towers. (favors East, West)

 20 - 4el SteppIR at 70'





back to main page