[Lowfer] WM gone flatline?

[Bill Ashlock]

Jay,

The antenna thawed out over night with the temp reaching a high of 39F around 3:00am. You must have seen the lack of modulation (below). I had it turned off this morning and was watching the supply current drop as the ground thawed out. When I left at 2:00pm it was down about 25% from the highest reading on Wednesday of 45ma (45ma X 22v = 1w at the final). I'm surprised to see that much change but the ground was getting fairly soft at that time. The effect of many feet of snow, later on, will be a new variable. Looks like I will have to install a correction pot in the shack to be able to compensate for these large changes.

The total Q of the system is about 250 with frozen ground and the test loading coil, so the tuning IS fairly critical. This goes up to a Q of ~330 when the better coil is installed. BTW, the wind becomes a factor with Qs this high. Interesting that the wet ground today didn't seem to effect the resonant frequency. The icing last night sure did! Probably the effect of doubling the conductor size in all of the wires.

I didn't get the opportunity to check the antenna with the current meter today, and unfortunately I'm back in Andover right now. At least I DID get to check on its calibration last night against my TEK current probe that feeds the scope.

Again, thanks for watching. The modulation should be back on right now. Hope my tree antenna here in Andover is still functional so I can also look. Should be here for a few days so we'll get to see how reliable that antenna actually is in all kinds of weather (2 - 4 inches of snow, tonight, for example).

Bill

From: jrusgrove at comcast.net
To: lowfer at mailman.qth.net
Date: Thu, 22 Dec 2011 07:13:46 -0500
Subject: [Lowfer] WM gone flatline?

Bill
 
How critical is the tuning on the new antenna?
 
Jay W1VD  WD2XNS  WE2XGR/2

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