Re: LF: VLF - G3XIZ QRT - MF QRV

[Chris Osborn <g3xiz@yahoo.co.uk>]

Mal, LF,

My loading coil is made using 0.35mm enamel covered copper wire.
Experience has shown that this is too fine for general handling and breaks down too easily.

Unfortunately the loading coil is as large as I can make it as a single unit so the inductance required governed the gauge of the wire.
I had to make the coil in my garage and then transport it through a narrow gate.
Even so it's quite a large unit.

The lesson is that a much longer aerial requires a smaller loading coil and then these problems would not occur.
Unfortunately I cannot greatly improve my existing aerial system.
Consequently I'm considering making a more robust and transportable design of loading coil which is why I asked for suggestions.

73 Chris G3XIZ

--- On Tue, 31/5/11, mal hamilton <g3kevmal@talktalk.net> wrote:

From: mal hamilton <g3kevmal@talktalk.net>
Subject: Re: LF: VLF - G3XIZ QRT - MF QRV
To: rsgb_lf_group@blacksheep.org
Date: Tuesday, 31 May, 2011, 16:04

Chris

Why is the wire insulation breaking down, is the wire too thin. Think of the amps an  alternator handles with pile wound copper enamel insulated wire.

Think of the problems you would have with a QRO rig if you are suffering breakdown with QRP

De mal/g3kev

 

----- Original Message -----

From: Chris Osborn

To: rsgb_lf_group@blacksheep.org

Sent: Tuesday, May 31, 2011 3:38 PM

Subject: Re: LF: VLF - G3XIZ QRT - MF QRV

Thank you Stefan,

 

I hope that you had a pleasant weekend and thank you for looking for the signal.

 

I have made some aerial improvements although not as much as I had anticipated.

I now have an inverted 'L'  48m long and with a mean height 11m

I have far better insulators too.

I shall do some more improvements later.

 

My loading coil became unserviceable yesterday at 06.10Z whilst transmitting.

I think that a flying insect hit the wires and exploded, causing a short-circuit.

I have had this problem before with insects with high voltages.

 

I shall try to rectify the coil and then see if my aerial shows an improvement in signal strength.

Eddie G3ZJO picks me up regularly and his VLF grabber is most useful.

 

Has anyone an easier way of making a 1.3 H loading coil ?

My present dual-overlaid winding coil took many hours to make and seems quite unreliable.

 

73 Chris G3XIZ

--- On Tue, 31/5/11, Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de> wrote:

From: Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>
Subject: Re: LF: VLF - G3XIZ QRT - MF QRV
To: rsgb_lf_group@blacksheep.org
Date: Tuesday, 31 May, 2011, 14:34

Hi Chris, VLF,

I have been 1600 km far away over the weekend but my grabber(s) was monitoring. Nothing seen here, unfortunately.
Good luck with your improvements!
I'll join in too, soon.

73, Stefan/DK7FC


Am 28.05.2011 11:41, schrieb wolf_dl4yhf:

Hi Chris,

Nothing seen here so far, but no big surprise considering the QRN.

Any copy of your signal by stations in DL or PA ?

73,
   Wolf DL4YHF / DF0WD .

Am 28.05.2011 11:31, schrieb Chris Osborn:

LF,

I'll be going QRT on VLF soon.
I'll then put out a few calls on 500 kHz CW and see if there's any life left on MF.

Anyone who wants a sked or a signal transmitted on MF or LF just give me a little notice and I'll try to oblige.

I'll be QRV on VLF again from 05.00Z tomorrow for several hours.

73
Chris G3XIZ