75m-40m AM QRO Antenna Recommendation - No Tower

[K1JOS]

I am setting up my first dedicated AM station for 75m and 40m.  I have a Viking 500 almost ready to go live and also buying a SuperSenior 80-40.  For SSB/CW I have a 2kW-ICAS EFHW that has worked very well but would not handle the Viking or SuperSenior.  I do have several 80-90' Black Locust trees near the shack but little room for ground radials.  Any advice would be very much appreciated.

Jerry NY2Kw

[KF4NU]

You already have ready made masts there, how about Inverted V's.

73's
Mickey KF4NU

[w9jsw]

An 80/40 fan dipole is what I use. Works perfect. I run a pair of 813s modded by a pair of 813s. Handles the juice just fine. Cut for the AM portion of both bands.

[W7TFO]

Thinking outside the box, a steerable tuned loop would magnify your ERP a bit...

73DG

[K8DI]

I’m similar to John on this with an 80-40-20 fan dipole, hung very slightly inverted V style. The ends are 5’ down. I run the RCA into it with no issues.  That’s a kilowatt plus of carrier converted broadcast transmitter, so, yeah, wire antennas can handle the gas…

Ed

[w9jsw]

Thinking outside the box, a steerable tuned loop would magnify your ERP a bit...

73DG

Some loop antenna information - https://kk5jy.net/magloop/

[KA7WOC]

Full wave loop has worked well for me.  I run open wire into a Kilowatt Matchbox.  Held up by trees.

[WD4DMZ]

For my AM set-up I use an MFJ 80/40 meter dipole. Total length is under 90 feet as a flat dipole. SWR is great for all of 40. Under 2:1 on 80 for about 100 khz, under 3:1 for over 150 khz.

If MFJ still has any in stock the 800 watt version runs under $100.

Inexpensive and easy to set up.

Rich

[W8EJO]

This may work for K1JOS with all those tall trees.

80-10 loop.

I recently downloaded the latest (free) version of EZNEC (https://eznec.com/) & have been modeling an 80-10 horizontal loop for my NW Michigan cabin. I have 5 acres & lots of tall trees but no tower. I’ll be heading up soon for an extended stay & wanted a simple multi band wire antenna.

After many tries I finally arrived on an isosceles triangular shaped loop that should cover 80-10 with 50 ohm coax feed (with 4:1 balun @ feed point).   

The loop is 274’ in circumference. The base is 80’ & each side is 92’.  Height is 40’.
The SWR 200 is below 2:1 on 40, 20, 15, 12 & 10. It is below 3:1 from 3.6 – 3.8 and 3.3:1 @ 18.1 MHZ.
A 4:1 balun @ the feedpoint should make modern rigs with internal atu’s happy.

Hopefully it actually works as well as EZNEC predicts. I’ll find out next week.

[w9jsw]

Does the circle on the plot denote the feedpoint?

[W8EJO]

Does the circle on the plot denote the feedpoint?

Yes.

I tried to attach the EZNEC file but that file type is prohibited.

[WD8BIL]

125' flat top, balanced feedline w/ link coupled transmatch.