Jim, tnx for sharing your direct experience.
Best 73 de Rik, IK2CAW
2013/10/18 Jim Bennett <w6jhb@mac.com>
> Rik -
>
> Last year we replaced the 20+ year old roof on our house. It was made of
> treated cedar "shake boards", with simple tar paper and plywood underneath.
> My antennas consist of (1) 26.8 meter long doublet fed with 450 ohm ladder
> line, (2) 80 meter Inverted L, (3) 160 meter Inverted L, (4) 5/4 wave 2
> meter vertical.
>
> The choice we had was to go with either concrete tiles or powder coated
> steel from Gerard . At first I was hesitant to do this, but the dollar
> difference made the decision for us - we had the powder coated steel
> installed. From what I can tell, it made almost zero difference in the
> performance of my antennas. Perhaps if I were to take the time (and a long
> time it would be) to model it in EZNEC, I might see a change in radiation
> pattern. However, I am still able to work the same amount of DX and
> stateside station as before. In addition, my antenna tuner apparently did
> not have to "re-learn" settings for that doublet. My suggestion is to go
> with whatever is best for you, either in cost or insulating efficiency.
>
> Jim / W6JHB
>
> p.s. - the roof we had installed looks exactly like the one here:
> http://www.gerardusa.com/steel-metal-roofing/products/barrel-vault
>
>
> On Friday, Oct 18, 2013, at Friday, 9:26 AM, Riccardo Negro wrote:
>
> > Hi all,
> > tomorrow I must decide which type of insulating system to be used under
> the
> > tiles of my new roof. Roof's structure is classic wooden and total
> surface
> > is 220 square meters.
> > Since there will be several antennas for 80 / 160 sorrounding the house I
> > am wondering if using insulating panels (polystyrene) covered with a foil
> > of ALUMINIUM (to reflect heath) could become a nightmare for antenna
> > resonance, pattern, etc.
> > The point is: better to have or not to have a roof with aluminium under
> the
> > tiles ?
> > Many thanks for your kind advice !
> > 73 de Rik, IK2CAW
> > _________________
> > Topband Reflector
>
>
--
Tel: 02 4549 8625
Fax: 02 999 831 89
======================================
ATTENZIONE
Tutte le informazioni del presente messaggio di posta elettronica, nonche'
tutti gli eventuali files inclusi sono confidenziali e ad uso esclusivo
del/i destinatario/i sopra indicato e pertanto oggetto di tutela ai sensi
del D.Lgs 30.06.2003 n. 196. Chiunque ricevesse per errore questo messaggio
e' pregato di notificarne allo scrivente l'errata ricezione e procedere con
l'immediata cancellazione dello stesso dal sistema. Qualsiasi utilizzo non
autorizzato del contenuto di questo messaggio costituisce violazione
dell'obbligo di non prendere cognizione della corrispondenza tra altri
soggetti, salvo più grave illecito,ed espone il responsabile alle relative
conseguenze civili e penali.
WARNING
All information contained in this electronic message and any attachments
are confidential. If you have received this message in error please delete
it immediately from your system. Many thanks in advance.
VALIDITA' TEMPORALE
Se il presente messaggio contiene una quotazione, la validità temporale
della medesima, se non diversamente pattuito, non potrà essere superiore a
30 giorni dalla data di invio del messaggio stesso.
QUOTATION SPAN
Should this message contain a quotation, the related terms and conditions
will be valid, in absence of specific indication, for a period of 30 days
max.
======================================
_________________
Topband Reflector
|