: Flat Aluminum 3/8" for Bi-Quad BQ4V


fireflimoon
2012-02-28, 09:39 PM
Hi,

I have some 3/8" flat aluminum and 10awg copper that I can use to build a BQ4V (this one ->
http://clients.teksavvy.com/~nickm/biquads/bq4V.html). Would there be much of a difference between the two for the elements? I was thinking of cutting and rolling aluminum flashing to make the four reflectors so I would not need to use either for those. Will the flat aluminum work much better than the copper wire?

Thanks in advance!:D

holl_ands
2012-02-29, 02:34 PM
AWG10 doesn't usually work all that well for Hi-VHF antennas.

Gain was essentially same with AWG10 or 1/4-in QICT (in nikiml's).
The worst case (lo-freq) SWR only increased from 2.2 to 2.8 and
mid-band never made it lower than 2.0 with AWG10.
Using 3/8-in Al (flat same as round) would push SWR just a bit lower.

So for this particular antenna, AWG10 would be acceptable.
You could also use AWG10 for elements and 3/8-in Al for Rods.

fireflimoon
2012-03-06, 09:19 AM
Thanks Holl_Ands,

Maybe I'll keep the flat aluminum for something else since using 10awg copper for the elements means I can make the rods out of aluminum flashing and save the flat aluminum for something else that needs it.

I was also wondering if there is an antenna that would benefit from being built with flat aluminum? Preferably for VHF-HI...I'd prefer a higher gain but not too narrow beamwidth (no rotor) that could be pointed at Mount Mansfield Vermont from a location about 45 minutes northeast of Montreal. I'd like to try it without an amplifier first using a short 50ft RG6 cable and maybe a coax balun - sometimes I get lucky making those. I'm going to get an amplifier, so that will come a bit later in case it is needed.


Thanks

holl_ands
2012-03-06, 01:07 PM
Wide beamwidth antennas for Hi-VHF: 2-Bay Bowtie and (HUGE) 4-Bay Bowtie:
http://imageevent.com/holl_ands/multibay

fireflimoon
2012-03-06, 04:03 PM
Thanks Holl_Ands,

I'm looking at the reflectorless bowtie 4 bay. Compared to the Biquad 4 for vhf from Nikiml's site the bowtie has a couple more db's raw gain. How can that be interpreted in layman's terms. Would it be possible to define what the difference 1 extra db makes for reception (is it the same kind of gain when you go from 5 to 6 db's as when you go from 10 to 11)?

:)

holl_ands
2012-03-06, 04:33 PM
When trying to receive weak stations, it is very difficult to see 1 dB difference in
antenna Gain, but 3 dB could make a difference. Of course if you're short by 5-10 dB,
a "mere" 3 dB increase isn't going to make much difference...