Re: Topband: 630m Crossband Weekend
For those interested, I have posted a summary of the event here: http://ve7sl.blogspot.ca/2015/11/630-crossband-excitement.html Steve / 73 WEB - "The VE7SL Radio Notebook": http://members.shaw.ca/ve7sl VE7SL BLOG - "Homebrewing and Operating Adventures From 2200m to Nanowaves": http://ve7sl.blogspot.ca/ _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Mag loop 400W if possible.
Depends upon small wire resistance change as it heats up. On Mon, 16 Nov 2015 10:30:50 -0500, Tom W8JI wrote: > Loss is I squared R. as the current is lowered then loss drops rapidly. That isn't true. Loss as a percentage or as a ratio to applied power is exactly the same in a linear system. 6 dB loss is 6 dB loss whether at 1 milliwatt or 1 megawatt. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Mag loop 400W if possible.
Loss is I squared R. as the current is lowered then loss drops rapidly. That isn't true. Loss as a percentage or as a ratio to applied power is exactly the same in a linear system. 6 dB loss is 6 dB loss whether at 1 milliwatt or 1 megawatt. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Mag loop 400W if possible.
It does not take a lot of RF if conditions are right. A few years ago I received a little 40 meters QRP transceiver for Christmas. Did not have a 40 meter antenna at the time. listened on my Beverage antenna, and everything was working OK. just for the heck of it, called a European and he came right back 559. I told him I was working QRP , the next transmission told him I was using a Beverage antenna and he signed off rapidly. 'Difficult to believe' Loss is I squared R. as the current is lowered then loss drops rapidly. 73 Bruce-k1fz www.qsl.net/k1fz/bogantennanotes.html On Mon, 16 Nov 2015 08:27:17 -0500, Tim Shoppa wrote: I have examined the RFI situation at some local apartment-bound ops on 40M and I swear when they work into their loop that it is their apartment wiring that is radiating, and not the loop antenna. It's gotta be worse on 160M. A guest op at a local contest superstation reported how hard it was to work DX the first morning on the high bands, then went to check out the antenna switching after a local with just a wire (aka me) was working the DX before him. He found out that all the QSO's he had that morning up to that point had been worked with a Heathkit Cantenna dummy load :-). Yes, it is very possible to work stations just using a Cantenna! (Possibly circa 30-40 dB down leaking into the beam, but I'm guessing feedline radiation can be similar too.) Tim N3QE _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Mag loop 400W if possible.
I have examined the RFI situation at some local apartment-bound ops on 40M and I swear when they work into their loop that it is their apartment wiring that is radiating, and not the loop antenna. It's gotta be worse on 160M. A guest op at a local contest superstation reported how hard it was to work DX the first morning on the high bands, then went to check out the antenna switching after a local with just a wire (aka me) was working the DX before him. He found out that all the QSO's he had that morning up to that point had been worked with a Heathkit Cantenna dummy load :-). Yes, it is very possible to work stations just using a Cantenna! (Possibly circa 30-40 dB down leaking into the beam, but I'm guessing feedline radiation can be similar too.) Tim N3QE On Sun, Nov 15, 2015 at 7:59 AM, jonathan white < jonathan.whit...@btinternet.com> wrote: > Hi I am in a bit of trouble I will be mooing to a flat/apartment ,so can > anyone give me details of a mag loop that will fit in a room and also be > able to be taken apart and resembled on a beach,will use big vac cap 1000pf > 40kv Russian type,any takers,and please dont laugh I love topband. > 73`s Jon g8ccl > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Mag loop 400W if possible.
Well everyone .going to view an apartment/flat in UK! Tomorrow and the seawall is less than 5mins away.The estuary of the river Crouch in Essex,UK. So will be able to run 100 watts of wsjt or whatever and qrp loop ant,for when its cold and wet.Ialso am trying to get a contest location notfar from new qth. thanks everyone. 73`s Jon On 15/11/15 21:03, Richard (Rick) Karlquist wrote: On 11/15/2015 4:59 AM, jonathan white wrote: Hi I am in a bit of trouble I will be mooing to a flat/apartment ,so can anyone give me details of a mag loop that will fit in a room and also be able to be taken apart and resembled on a beach,will use big vac cap 73`s Jon g8ccl For the beach, get a collapsible telescoping pole and make a vertical on the beach. Add a loading coil and a couple of radials and you're on the air. Way better than a loop. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
