Envelope-to: dave@picks.force9.co.uk Delivery-date: Sat, 05 Nov 2005 00:32:15 +0000 Received: by pih-mxcore18.plus.net with spam-scanned (PlusNet MXCore v2.00) id 1EYByh-0005Lb-CR for dave@picks.force9.co.uk; Sat, 05 Nov 2005 00:32:15 +0000 Received: from post.thorcom.com ([193.82.116.20]) by pih-mxcore18.plus.net with esmtp (PlusNet MXCore v2.00) id 1EYByh-0005LV-8M for dave@picks.force9.co.uk; Sat, 05 Nov 2005 00:32:15 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1EYBxx-0006oQ-AV for rs_out_1@blacksheep.org; Sat, 05 Nov 2005 00:31:29 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1EYBxw-0006oH-Pq for rsgb_lf_group@blacksheep.org; Sat, 05 Nov 2005 00:31:28 +0000 Received: from imo-m21.mx.aol.com ([64.12.137.2]) by relay1.thorcom.net with esmtp (Exim 4.51) id 1EYCkb-0003Xk-CH for rsgb_lf_group@blacksheep.org; Sat, 05 Nov 2005 01:21:46 +0000 Received: from MarkusVester@aol.com by imo-m21.mx.aol.com (mail_out_v38_r6.3.) id l.66.63472a3e (1320) for ; Fri, 4 Nov 2005 19:31:19 -0500 (EST) From: MarkusVester@aol.com Message-ID: <66.63472a3e.309d5757@aol.com> Date: Fri, 4 Nov 2005 19:31:19 EST To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Mailer: 8.0 for Windows sub 6104 Subject: Re: LF: toothbrushes Content-Type: text/html; charset=windows-1252 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SpamFiltered: by PlusNet MXCore (v2.00) Content-transfer-encoding: 8bit Hi Laurence and LF,

I have used ~ 40 cm helium balloons a couple of times, to get on air with 60 to 100 m of thin 0.4 mm copper wire. The balloon was closed off by a small upside-down plastic bottle (ex body lotion, or the like), with a hole in the base coverd by a piece of tesa tape as a filling valve. The wire end was simply wrapped around the neck of this bottle, with no extra length of nylon filament or insulators. Ran up to abt. 3 Amps RF into it without any problems. "Ground-based" experience with my 200 pF topload showed that corona near the wire ends can be reduced further by paralleling two (or more) thin wires for the last couple of meters, with a U-turn at the end and two 5 cm lightweight spacers.

Actually I was never very much worried about the balloon coming off the wire, but more concerned about not letting it off near the bottom end, with the risk of a string of copper shorting some high voltage powerline, possibly causing an arc after meltdown.

Running off my balcony, the balloon tended to drift off in the lightest wind, and the line kept getting entangled in trees, roof tiles etc. In a later experiment, I used a shorter and even thinner wire (abt. 10 grams), fixed to the top of my LF fishing pole, and acting as an effective replacement for the downwards sloping topload wires.

73 and good luck

Markus