H I, Herb Well, I expect that your 80/160 delta loop can be made to play well. Do you use EZNEC? It's heck of a lot easier to deal with the interactions with a keyboard and mouse than raising and lowering and pruning the loops! :-)
73, Charlie, K4OTV -----Original Message----- From: Topband [mailto:[email protected]] On Behalf Of Herb Schoenbohm Sent: Monday, September 02, 2013 7:09 PM To: [email protected] Subject: Re: Topband: Nested Loops with one feedline results Thanks Rick, I presume a true quad loop would bring different results with a common feed. I have heard of a single feedline working well with a 5 band quad so I presume that a triangular "Delta Loop" has a completely different relationship? Herb, KV4FZ On 9/2/2013 6:34 PM, Richard (Rick) Karlquist wrote: > The 18/24 is not a good analogy, because those bands are not octave > spaced. My modelling indicated that you need to open up the lower > frequency antenna at two places, 180 degrees opposed, in order for it > not to affect the higher frequency antenna. Also, the openings should > be such that the remaining wires are cross polarized to the higher > frequency antenna. > > Rick N6RK > > On 9/2/2013 3:09 PM, Herb Schoenbohm wrote: >> Several replies to my inquiry on having a closed 80 meter inverted >> delta loop inside a 160 meter delta loop brought me some nice >> replies. So I decided to build one for 18Mhz and 24Mhz with the feed >> going to the outside Delta loop hoping this would properly allow dual >> band operation with a single feed. The inside 24 Mhz delta was >> closed and hung inside a the fed 18 Mhz antenna. The results showed >> that it had no impact on the >> 18 Mhz antenna but the VSWR on 24.9 was unusable. Then I decided to >> open the 24 Mhz Delta and connect the two wires to the 18 Mhz feed >> and now have both bands working with a VSRW below 1:2 to 1 on either band. >> The feed-line for the antenna is RG-213 with a 1/4 wave piece of >> RG-11 cut for 18 Mhz. I am surprised that the 1/4 wave matching >> piece did not seem to impact the antenna on 24.9 at all. >> >> I will now proceed to build an 80 meter full wave delta inside my 160 >> meter one and rely on the simulation on 18/24 Mhz to get a good >> match. I trust it will work although the ground proximity might have >> some impact on everything. >> >> >> Thanks for the replies on this. >> >> >> Herb Schoenbohm, KV4FZ >> _________________ >> Topband Reflector >> >> > _________________ > Topband Reflector _________________ Topband Reflector _________________ Topband Reflector
