Upgrading my HF Base Station 6

Recently I’ve been slowly but surely upgrading my HF base station at home. After deciding an ICOM 7300 was more than enough for my operating needs and that any new shiny radio would NOT help me work any more stations, I turned my attention to the other things I could improve.

The first thing was clearly the antenna, after sticking with a simple Western HF-10 wire antenna for a few years, it was clear this was a compromise. Covering everything from 80m up to 6m is a push. I found this antenna to best perform on 30m and 80m, but elsewhere it was hard work!

I went for an AWK Antennas Cobwebb which covers seven bands (20m/17m/15m/12m/10m/6m/4m). You can read more about my experience of building this here.

The finished Cobweb in the air

The finished Cobweb in the air

I initially used an old run of RG58 coax, which is clearly not the best and also with my eyes on an amplifier, absolutely not suitable for QRO! I instead made up a new run of Messi & Paloni Ultraflex 7, complete with quality QRO ferrite toroids (FT240-43) at each end.

At this point it was time to bring my second hand ACOM 1000 amplifier inline, so I connected everything up, including the keying line from the ICOM 7300 to the amplifier. Now up until this point I’ve been mostly a QRP man, so amplifiers are new territory (outside of contest groups and field day). The ACOM 1000 can output up to a maximum of 1.2kW, so clearly it’s only going to loaf along at UK legal limit of 400w. This gives me a lot of headroom to run data modes at 400w and not push the amp too hard, I can also be sure it remains linear, as I’m only running it at a third of its total output.

ACOM 1000 amplifier chugging along

ACOM 1000 amplifier chugging along

I’ve done tests with a local amateur (thanks Malcolm G3ZNU) to make sure my FT8 signal is as clean as possible and at 400w it caused them no issue (other than it being very strong)!

The results have been a sharp increase in DX worked on HF, with several all time new ones in the log, including Seychelles, New Zealand, South Africa, St Lucia and Korea. It’s also been a new experience to work pileups of JA and west coast North American stations on 20m FT8…

Pileup of JA stations on 20m FT8

Pileup of JA stations on 20m FT8

 

Being received well in JA on 20m

Being received well in JA on 20m

 

So in conclusion, it’s safe to say the upgrade was worth the effort, I’m now finally working some DX on HF and have almost reached DXCC. I’m still very much interested in QRP, but QRO has added another dimension to my operating and opened up a world of DX for me.

New station setup

New station setup

My transformed log book

My transformed log book

6 thoughts on “Upgrading my HF Base Station

  1. Reply Jim Brown Oct 13,2020 02:12

    Your use of a #43 Fair-Rite core to use as a common mode choke is a VERY poor choice. Fair-Rite #31 is the only good choice for the HF bands, and it’s also the best choice for 160M and 6M. See my cookbook, at k9yc.com/publish.htm

    • Reply James Stevens Oct 13,2020 10:41

      Hi Jim,

      I thought #43 would be ok because I’m only using 20m-10m and not the lower HF bands. Thanks for the link Jim, I can see you’ve done a large amount of analysis on this topic, so thanks for the tip. I see another station enhancement coming up soon!

      73 James M0JCQ

  2. Reply Ian Oct 13,2020 09:47

    It’s been a while since I’ve been on digital modes (or the radio at all to be honest)…but don’t people get a bit upset with people using high power there…with about 25 watts being the max ? I’ve never heard of someone using 400w !

    • Reply James Stevens Oct 13,2020 10:29

      That’s not been my experience over the years Ian. I guess the usual wisdom is data modes are typically ‘low signal’ rather than ‘low power’ modes. As soon as HF conditions support lower power, then I’ll be the first to drop the power, but being near minima makes it tough work right now.

      73 James M0JCQ

  3. Reply Mark Wickens Oct 13,2020 10:44

    How do you install the toroids James please?

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