[MRCA] Manpack HF antenna Ideas?

[Christopher Bowne]

Re using short vertical antennas at low frequencies, I can’t speak about manpack applications but over many years of mobile operations I can tell you that you that you can work low band DX with short verticals, at least with a vehicle body as a counterpoise. Most of my low band DXing has been conducted from shore side locations in close proximity to salt water but I’ve also worked considerable DX in the 75 meter SSB DX window from locations many miles inland.

From the shoreside locations I have regularly worked into Australia both long and short path, and Japan on long path on 75 SSB, and recently I’ve been been running 160 mobile using an old 1960s 2 MHz marine band n
center loaded boat 12.5 foot whip, resonated on 160 with a simple homebrew LC matching network at the base.  I’ve made CW QSOs on 160  out to Hawaii, Aruba, and several other of the St. Somewheres, and across the pond to Germany and Madeira.  I’ve recently operated in 4 160 CW contests strictly as a mobile, and worked all over the country, most recently in the CQWW 160 contest a few weeks ago.  All contest operation was conducted while parked on Stonington Point about 10 feet from the water.  Made over 250
contacts in about 7 hours of operation, mostly by making long  CQ runs, had a 60Q hour rate over 3 hours at one point. 

Someone (Jeep?) mentioned a Webster Bandspanner- if you can find one it’s a great mobile antenna covering all bands 80-10 and all of the WARC bands including 60 meters, and I can see how it would be very good manpack antenna.  I would think that with a decent set of counterpoise wires , say 8 or 16 35 footers, to work against with one mounted on a pack frame in a manpack station it would do quite well on low bands. I’ve thought about building such a manpack setup myself so now this thread has inspired me to do one with my Bandspanner, would most likely use my IC-7100.  What I need to learn the most about it coming up with a decent capacity battery system.  I know that both the 7100 and 7300 Icom transceivers will deliver full output on a fully charged lead acid car starting battery, I ran them off a single Group 24 battery for at least 6 hours on last year’s Field Day doing non-stop CW and never had any loss of output, with battery voltage never dropping to below about 12.1 volts.  My original mobile transceiver, an FT-100D did not like running on battery only, even a fully charged one for very long, output would drop noticeably and it would chirp badly on CW, and FM on AM and SSB.

Based on my experience with Hamsticks and the Bandspanner, I don’t think you would need anything more than a shunt capacitor at the feed point to get a good match, probably 1000 pf on 80, 500 pf on 60 and 40, and possibly no shunt cap on higher bands working against a good set of counter poise wires.

Interesting thread.  By the way, there is a Facebook Group called Real HF Mobile that focuses on both mobile and manpack mobile/portable operation, primarily UK
ops but also folks from many other countries.

I like the look of Brett’s center loaded whip coil what’s the estimated uH, and it’s dimensions?  Dimensions of the whip above and below the coil?

Chris AJ1G, Stonington CT

Sent from my iPhone

> On Feb 17, 2023, at 12:28, mstangelo at comcast.net wrote:
> 
> My experience is not that severe.
> 
> I lot's into the Moose and Squirrel net and various 40 meter nets, at least once a week, during the summertime, mostly from the beach. If I can work into the net with the wire antenna I can also work them with the Hustler but with a lower signal strength.
> 
> My wire antenna was described in a previous email. I usually mount my Hustler on the car or on a table. I do not depend on the mag mount coupling to the car body for a ground (I have felt on the base to prevent scratching). I mounted a lug under the mag mount stud base to attach four counterpoise wires.
> 
> Proximity to the salt water may help the propagation but I have had the same experience from Vermont when I take my wife skiing.
> 
> The quarter wavelength wire is better, but the vertical ( with counterpoises) does the job when nothing else is available.
> 
> I normally run 40-50 watts from by FT-897.
> 
> Mike N2MS
> 
>> On 02/17/2023 9:40 AM Ray Fantini <rafantini at salisbury.edu> wrote:
>> 
>> 
>> Perhaps its antidotal because it’s an opinion founded on my own experience but I have never found a small vertical to be of much use on forty and below.
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