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Low Band QRP

 

As AA7FO mentioned this matter, here is what I can share. ?
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On 160m I have had several CW QSOs with folk operating simple tube transmitters at 5 to 10 watts. ?So it¡¯s definitely viable during the cool season. ?Each year QRP ARCI runs a 160m contest and I have enjoyed memorable QSOs with well-known QRP ops. ?Then for a few years I missed it, as it occurs mid week before the ARRL contest. ?I operated some years in that ARRL contest running 5 watts, into an inefficient short vertical (MA160V) at my prior QTH and did okay. ?
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On 80m of course it¡¯s a bit easier. ?In my stash of QRP rigs is an 80m design by Dan Tayloe kitted by the Az Scorpions- not recalling its name but it was a non-cancelling direct conversion transceiver. ?Sitting in my shack just now is a QCX+ operating with its matching PA that operates around 20 watts output (when run at 13.8 volts) - a fun addition but it also does okay barefoot. ?
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I also operated a little WSPR and found when dropping down to 80 and 160 meters my 300 mW signal from a QRP-Labs U3S did not cross oceans as I did on 40 meters and up - but with better antennas at my present QTH I will try again. ?Here I am using an 80m EFHW configured as an inverted V for 80 and 40 meters, and I have a full size 160m inverted L (now that I have trees to host it here). ?
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No tube transmitters or all band receivers made my move, but I have a simple IRF510 transmitter for stalling operation on 80 and 40 meters. ?Oh and a 160m LPF assembled for use with my uBITX. ?
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QRP is viable on the low bands, and of course old-fashioned VFO and PTO work well down here. ?Still we should have opportunities at the upper spectrum for a few more years (I hope) for this cycle. ?
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Curt wb8yyy
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The price of admission for 160 is an efficient antenna.? I'm probably at the low end with a 165' inverted-L up 75' with 47 mixed length radials from 15 to 70'.? I use a K2 at 5 Watts.? ?
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I like the Stew Perry event held around the end of the year.? Participation is dropping off and the propagation (good for the higher bands!) is not so good for 160.? I've gone from 194 QSO's in 2020 to 81 this past year.? In 2020, I forgot and started out at 10 Watts, reducing my power to 5 Watts as I got rolling - so to keep a clean conscience I had to put myself in the QRO division.?
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I had 24 QSO's in the recent NAQCC 160 meter sprint.? ?
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I've had to deal with local noise issues, one of which was a nearby sodium street lamp that was trying, and failing, to ignite.??
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I've pretty much avoided the 160 contests/sprints during the warmer months because of the noise levels. YMMV
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73
Jerry W
KI4IO
Warrenton, VA
 

@ KI4IO:? Yes, agree 100% that on 160, it's all about the antenna. But I think your particular inverted-L is a bit higher up in the ranks than you might think. In 2017/2018, when the ionosphere was still in "low band" mode and all the high bands were dead, I worked WAS 160 QRP CW in three months of casual contest participation. (DXCC entities total 21 to date on 160.) I ran 5 W to my own inverted-L, which has a meager 40-foot vertical run and the rest horizontal, out to a treetop (107 feet in total).

I have 32x, 45-foot ground radials, and I have an autotuner in an insulated box at the feed point. There's a large relay in there, too, to select between 107-foot and 41-foot wire elements).

Compared to any horizontally polarized antenna I've ever used, this is a KILLER antenna for the low bands. I wish I would have figured this out about 40 years ago. :)? Since I arrived on the bands in 1977, I had worked about 10 DXCC entities on 80 meters and none other than Canada on 160. Since the "vertical era" My 80-meter QRP entity tally is between 50 and 60, with 160 at 21.?

I was really worried about working KH6 on 160 QRP...until I worked 8 in one evening because there was a bona fide OPENING. :) ? That opening also put JA and VK in the QRP log on CW. Thanks to the wire vertical I am now only a handful of states away from 5BWAS QRP. Ironically, only the nearby ring of states on 15 and 10 meters remain... The vertical has been of no help there.

At any rate, for low-band DX, go vertical!?

Horizontal antennas of any type still put QSOs in the logbook locally and regionally, even at QRP, but DX is extremely limited.

Regards,

Kirk, NT0Z
Rochester, MN

PS Propagation on the low bands during solar peaks (now-ish) is generally terrible, which is why I'm trying to fill in stuff on the high bands nowadays. I need only AK and HI to make WAS QRP on 6 meters. DO you think I could catch a break with an afternoon of F2? Not so far...


My book, "Stealth Amateur Radio," is now available from www.stealthamateur.com and on the Amazon Kindle (soon)


On Saturday, May 3, 2025 at 07:24:42 PM CDT, Gerald Wolczanski via groups.io <jerrywlinux@...> wrote:


The price of admission for 160 is an efficient antenna.? I'm probably at the low end with a 165' inverted-L up 75' with 47 mixed length radials from 15 to 70'.? I use a K2 at 5 Watts.? ?
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I like the Stew Perry event held around the end of the year.? Participation is dropping off and the propagation (good for the higher bands!) is not so good for 160.? I've gone from 194 QSO's in 2020 to 81 this past year.? In 2020, I forgot and started out at 10 Watts, reducing my power to 5 Watts as I got rolling - so to keep a clean conscience I had to put myself in the QRO division.?
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I had 24 QSO's in the recent NAQCC 160 meter sprint.? ?
?
I've had to deal with local noise issues, one of which was a nearby sodium street lamp that was trying, and failing, to ignite.??
?
I've pretty much avoided the 160 contests/sprints during the warmer months because of the noise levels. YMMV
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73
Jerry W
KI4IO
Warrenton, VA
 

Kirk?
Wow, you've really done well.? My annual forays on 160 can be counted on one hand.? I'm not much of a contester and I don't chase various awards.....but I've found the Stew Perry event much to my liking.? I'm good for about 6 or 7 hours before I'm exhausted.? I have no idea how some big time contesters maintain such high QSO rates for extended periods of time.
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There's an interesting piece floating around on the internet about W1BB's favorite antennas.? ?It's at:
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I'm quite struck by Stew's high opinion of an inverted-vee with an apex of 50' to 70' with the ends 15 - 20' off the ground.? Typically antennas this low are viewed as cloud-warmers.? Maybe, given his QTH on the densely populated Eastern seaboard, such an antenna would be very fruitful in a contest.? I can think of no other reason.
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73
Jerry W
KI4IO
Warrenton, VA
 

On Sat, May 3, 2025 at 02:58 PM, Curt wrote:
In my stash of QRP rigs is an 80m design by Dan Tayloe kitted by the Az Scorpions- not recalling its name but it was a non-cancelling direct conversion transceiver.
It was the Fort Tuthill 80, known also as the Tut80. It's a nice little rig. I modified mine for varactor tuning with a 10-turn pot (suggested by Cam N6GA) and a KD1JV Digital Dial, as well as modding the PA for a little more power, with a mod suggested by Dan. For a while, Pacific Antenna were selling versions for Top Band and 15M. I thought about acquiring one of them, but didn't get round to it before they sold out. I have also thought about looking for another original 80M one and modding it for 40 but you know how these things go - lots of ideas but limited time and energy!
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I have only used it occasionally, but my one big success was using it to QSO with the T32C DXpedition team on Christmas Island, with the Tut80 into a co-ax fed 40M dipole! By all accounts it shouldn't have worked, but it did, and the ops at T32C had great ears.
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Dave
AA7EE

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