Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: OP32 136K TA Opportunity tonight

To: <[email protected]>
Subject: Re: LF: OP32 136K TA Opportunity tonight
From: "Markus Vester" <[email protected]>
Date: Tue, 2 Apr 2013 22:19:21 +0200
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1364933998; bh=MbWNrE50qnaeAWJ/Xba3DLrovZ4qEZG6guD/s1UI6Eg=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=jermOlPjmGAinY/RvwlOO8Dl3stfSxMxjXT22EADqwrCOW0t66zvLfBG1cKVeTz6Z JpL1h5rK3iaprQ9ttGjBN2xVud3GidymtrfypBGSYHGL/bjQvEHDQGsgJInrgUqLsh 1aAwnEon6D/hU3FWQyfFpXqsnPiwDGiCmN54BbhM=
Reply-to: [email protected]
Sender: [email protected]
Joe, LF,
 
thanks very much for this report, I am very pleased that you (again!) managed to pull my signal out of the noise. People like you make all the effort worthwhile.
 
Here's a follow-up on the antenna and coil story. On Sunday, the first Decca litz prototype gave up after only three minutes, with a sudden loud screetch and loss of resonance. Careful inpection showed that it had arced in a gap between two segments, where I had not laid the turns carefully in the correct order, inadvertently overcrossing wires with a larger voltage difference. My first thought was what Stefan's comment would be about me ruining the precious litz!  Anyway I unwound the coil completely and taped the defect
Then I rewound it more neatly on a new bucket, this time using only three layers and shorter segments to reduce the internal voltages (3x5 turns instead of 4x9). The remaining long wire end was used for a smaller variometer insert (1x40 turns) to coarse-tune the inductance:
As I had hoped, the AC resistance on the the network analyzer had dropped from 6.6 to 4.3 ohms (Q = 1000). The coil is also thermally more open to air than the old one. Then I ventured into the unavoidable nail-biting WSPR-15 soak test... no arcing and no heating this time, the coil actually stayed completely cold. In the dark there was no visible corona anywhere. But the noise level on the FM broadcast band increases sharply when I transmit, indicating that there must still be some partial discharges lurking somewhere in the system.  
 
To be able to transmit overnight, I repositioned the temporary support mast from the rooftop window to the balcony:
 
For the three Opera transmissions last night, I cranked up the power to about 440 W, driving 4.6 A (22 kV) up to 9 m effective height. This happens to be almost exactly one watt ERP. 
 
Best 73,
Markus (DF6NM)
 
 
----- Original Message -----
Sent: Tuesday, April 02, 2013 3:16 PM
Subject: Re: LF: OP32 136K TA Opportunity tonight

Dear Group,

Despite very high mains noise levels there were 2 Op32 receptions
of DF6NM at 0000 and 0449 at -37 and -35 dB respectively.

73
Joe VO1NA

On Mon, 1 Apr 2013, Graham wrote:

> OP32 136K TA Opportunity tonight
> Joe  VO1NA  will  be  monitoring   136.00 K tonight  for  OP32
> Good  luck all
>
> 73-Graham

<Prev in Thread] Current Thread [Next in Thread>