Thanks for all the replies so far.
I would expect that the 160m ends would tie off at different locations
thus keeping a decent separation of the wires and ends. I plan on
having an autotuner so I think we will be ok. I just found out that the
location is actually 100 ft from the ocean but up about 200 ft so I am
considering going back to a vertical. The V will take up far less room
but the vertical should work better.....decisions decisions.
On 4/20/2011 3:35 PM, Dick Green WC1M wrote:
> I've had good results on CW using a 80/160 trapped inverted vees made with a
> pair of Unadilla/Reyco traps.
> 73, Dick WC1M
> -----Original Message-----
> From: Mike Fatchett W0MU [mailto:firstname.lastname@example.org]
> Sent: Wednesday, April 20, 2011 2:26 PM
> To: email@example.com
> Subject: Re: [TowerTalk] Inverted V for 160/80 on the same feedline
> In theory then you should be able to get a decent swr for both bands. I
> don't really care about the bandwidth too much as they will be used for
> CW in a contest.
> The goal is to have a good match and a single feedline for weight,time,
> baggage considerations for travel.
> On 4/20/2011 12:20 PM, Jim Brown wrote:
>> On 4/20/2011 10:53 AM, Mike Fatchett W0MU wrote:
>>> This might also be called a Fan dipole.
>>> Can you run 160 and 80 on the same feedline with decent swr? I have
>>> tried to model this and have not been very successful.
>> The short answer is yes, sort-of. In general, the longer antenna will
>> show the same SWR bandwdith as it would without the higher one, and the
>> higher one will have it's SWR bandwidth reduced by about half. My
>> experience is with 80/40 fans, and with 20/15/10 fans, and these
>> characteristics show up both in the NEC models and in measurements of
>> real antennas.
>> This is exactly the opposite of what happens with the loaded multi-band
>> dipoles like those sold by Hy Power Antenna Company -- the higher band
>> antenna retains full SWR bandwidth, and the lower frequency (loaded)
>> band has reduced SWR bandwidth. I've also modeled those antennas, and
>> like them a lot. In boht cases, the reduced SWR bandwidth can be
>> compensated with a tuner and losses minimized by using low loss feedlines.
>> For more detail, see my applications notes on Antennas for Limited
>> Space. There are two that compliment each other -- one is text, the
>> other a power point presentation.
>> 73, Jim K9YC
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