James: The -43 core is recommended down to 1 MHZ and declines in performance just a little down to .5 MHZ so you should not have a fatal problem with the 43.
What you do need is a more turns of wire. You need a minimum of 10 turns on the rx side and 30 on the antenna side for a -43 core at .5 MHZ. That's a fair bit of wire to wind. Because of that, and because the losses are a little lower, people use 73 or 77 cores for medium frequency work where you need. For a simple, guaranteed-to-work transformer, take a look at http://www.w8ji.com/core_selection.htm then scroll down to the Beverage matching transformer. You'll need to change the number of turns on the antenna side so that there are about 8 turns. With your 6 turn winding, you have about a 66 Ohm winding across your receiver input so basically half the signal is getting lost at .5 MHz. Does that match up with what you mean when you say it is "dead"? Chuck -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of James Niven Sent: Monday, January 08, 2007 6:03 PM To: Mailing list for the International Radio Club of America Subject: Re: [IRCA] Recent logs from Moody, Texas Hi Craig, On each antenna there is a 9:1 matching transformer with 6 turns on the receiver side and 18 turns on the antenna side. The terminating resister is 680ohms. The toriod is FT-114-43 purchased from Amidon. Each antenna is feed with 4 separate RG6 runs to a 4 position rotary switch. Thanks James Niven ----- Original Message ---- From: C B <[EMAIL PROTECTED]> To: Mailing list for the International Radio Club of America <[email protected]> Sent: Monday, January 8, 2007 7:48:29 PM Subject: Re: [IRCA] Recent logs from Moody, Texas Hi James, Did you equip your EWE with an impedance matching transformer and a terminating resistor? Craig Barnes Wondervu, CO --- James Niven <[EMAIL PROTECTED]> wrote: > Hi All, > > After working on my EWE antenna 10x50x10 in the > spade of a + sign, this is 4 antennas. It works very > well on frequencies above 1350khz and very > directional. > Before the EWE was commissioned, I was using a 300 > foot longwire pointing south. > > On 1570khz XERF justs booms in with a monster > signal. Now with the EWE, I am able to knock down > XERF and I logged KSXT in Loveland CO last night. > Tonight I heard a country station with a slogan as > "Country Legends 15-70". It just disappeared like > changing to night pattern. Anyone know who this may > be? > > On 1600khz I logged KRKE in Albuerque, NM before > changing to night pattern with rockin Oldies, nice > signal. > > I am not sure why the EWE is not working on the > lower part of the band, it appears to be dead. > Anyone offer some suggestions? > > Thanks > > James Niven, > Moody, Texas > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam > protection around > http://mail.yahoo.com > _______________________________________________ > IRCA mailing list > [email protected] > http://montreal.kotalampi.com/mailman/listinfo/irca > > Opinions expressed in messages on this mailing list > are those of the original contributors and do not > necessarily reflect the opinion of the IRCA, its > editors, publishing staff, or officers > > For more information: http://www.ircaonline.org > > To Post a message: [email protected] > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected] __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected] _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected]
