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de ultime zelfbouw fm antenne?


kww
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P.s. lees net in de krant dat de huidige FM frequenties in 2011 niet geveild worden

en dat in 2011 sterkere en meer FM zenders neergezet gaan worden.

Hehe ze snappen het eindelijk in den Haag :D

 

En nu maar hopen dat er goede betere bandpass filters gebruikt gaan worden anders is er dichtbij de zender nog maar een paar zenders te ontvangen.

Op sommige locaties is dat nu al een probleem.

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  • 1 month later...
Guest tubejack
De link werkt niet meer, de Skywaves hebben een nieuw forum. Heeft iemand de bouwhandleiding toevallig opgeslagen?

 

Nee, het was een vierkant van 82cm coax per kant. Aan

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De link werkt niet meer, de Skywaves hebben een nieuw forum. Heeft iemand de bouwhandleiding toevallig opgeslagen?

Gelukkig hebben we het internet archief nog:

 

http://web.archive.org/web/20071103163407/...HTML&id=139

 

Naar beneden scrollen en je bent weer thuis :D Save die pagina dan gelijk lokaal op je HDD.

 

 

 

<quote>

 

The construction bit

 

This aerial uses Bodgitt & Scarper technology. It is so simple even I knocked one up in a matter of minutes. You don't need to rely on my design, however, you may wish to make the construction a lot more sturdy, but the purpose of this article is to show how you can achieve good results with the simplest of constructional effort. If you are going to use the loop externally for an extended length of time you would need to give it more strength. I constructed the loop quickly to use in mobile situations where I just throw the loop up into a tree or hang it on a branch. I will get round to constructing something more solid one day - perhaps! This is what I used ...

 

* Square wooden dowelling around 2cm thick (around half an inch). Enough for four x

84cm lengths = 336cm total (or 4 x 33 inch lengths = 132 inches total).

half an inch square).

* At least 15 metres (50 feet) of good quality 75 ohm coax cable

* Screw terminal blocks

* Sticky tape - duct / gaffer variety

 

Alternatively, you could construct the loop out of plumbers copper pipe instead of coax and some 90 degree corner joints. Make sure you insulate the copper though with thick tape though if you intend to hang the loop on tree branches. Any physical contact *may* degrade performance.

 

The receiving element itself is a 33 inch 84cm square loop of the coax, so you will need to construct a suitably sized wooden frame, say 10mm (half an inch) less each side of the wooden dowelling around which you will wrap the coax - this is to make allowances for the coax which will then be the correct size. The coax needs to have a feed point half way along the bottom of the frame so cut coax to a 336cm (11 feet) length and wrap this around the frame ensuring the inner core and outer (braid) are connected together, each end going into separate connections on a small electrical screw terminal block. The remainder of the coax will be used for the downlead - you can vary the length accordingly. Connect the two ends of the loop to either side of the coax downlead via the terminal block, either way around, it doesn't matter.

 

The impedance of the FM Loop is 75 ohms. There has been much debate about this but this is stated in ARRL and RSGB information. Also, recent computer modelling has given the impedance as 75 ohms at resonance too. The loop should be positioned broadside to the transmitter for best pick-up, while the nulls can be found endways on. The loop also seems to have other quirky attributes, exhibiting a slightly unidirectional pattern at times, but these quirks can be of great use.

 

..................

 

John Faulkner

 

</quote>

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  • 1 year later...
Guest tubejack

Ik zie regelmatig mensen kijken in dit topic.

 

M.i.

Beste weinig opvallende antenne Magnum Dynalab ST-2 ongeveer 150€

Er is ook een goedkoper alternatief, wel even opletten dat je de goede koopt

metz part number 288

http://www.metzcommu...n.com/am-fm.htm

Leverancier weet ik zo niet 1-2-3

 

Goedkoopste.

 

Raamantenne 2 stukjesdraad van 73cm in een kroonsteentje en coax aansluiten

vertikaal ophangen eventueel draad verlengen met gewoon touw.

Kosten ongeveer 3€

 

Het goed plaatsen van antennes is nog een kunst.....

Uit de oude doos....

 

http://www.tubejack.nl/antenne.php

 

Vriendelijke groet,

 

Jack

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