The 'elusive' Diamond RHM-12

Happens in VK too, more along the lines of 40m hips, knees and elbows nets. :joy:

Andrew VK1AD

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Couldn’t get out yesterday as the weather was absolute trousers. Took Barry and the KX2 up to a POTA spot and just tried to test things out, get used to tuning the RHM-12 and so on.

This is a snap of how I set it up. Couple of points of note:

  1. I only used 2 radials. I haven’t made 2 more yet.
  2. I didn’t bring a whopper tripod, just a portable Manfrotto. I will test though at some stage.
  3. I ran 10w on the KX2 voice only as I was short on time.

Here’s some snaps. You can see tuning on 40m was super easy. 20m not so much but I think it was more due to the set up and proximity etc. Sorry for the rubbish Rigexpert snaps, it was strong sunlight even with the colours inverted. Usually I use the black and orange setting.

Also, the second I switched on the KX2 I was on a frequency where a chap in Belgium was doing a QRP WWFF. I got a 57 RST and he was a 59 to me. What a fluke!

Tried another contact on 20m in Germany but he couldn’t copy my whole callsign due to noise. A shame but nice I was heard.

I did set up the 70cm antenna and radial, also the 2m setup using the enclosed string to measure the whip. Worked a treat as I was able to break squelch on repeaters (no sod was listening so no contacts, but break squelch I call that a success!).

Barry seems to be performing amicably. Next I am going to try using my FT891 with 100 full-fat, premium Yaesu Watts and we’ll see how that goes!

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Tested setting up the RHM-12C additional coil for 80m last night and it worked a treat in terms of ease of set up and tuning.

80m seemed a bit dead when I tried scanning but I did hear a net based in Oxford, though wasn’t heard (sure it was set up in my back garden). No mentions of gout or miscellaneous ailments or gatekeepers though alas - a first for 80m?

Here’s what my RigExpert was showing anyways. Thought to show an example if it helps anyone in a pinch on a summit.

inage deleted I uploaded the same 40m image and just noticed the image of 80m didnt save on my blower! Apologies. Anyways I was getting about 1.04:1 with a similar curve on the chart. Works really well! Here’s a photo of a 1986 Austin Maestro camper to make up for the lost image, my apologies.

I didnt try out the other 160m coil yet. The gout probably intensifies on top band… :face_with_peeking_eye:

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Restez simple et utilisez des antennes simples et efficaces :+1:

The structure reminds me strongly of a Tibetan prayer wheel… you pray for four QSOs

:wink: 73 Armin

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I just got this

GRA-M105 Ultimate Portable M10x1.0 Connector Manpack Collapsible Whip Antenna: Enhancing GRA-RPG Series with 3/8"-24 Adaptor, 235.5cm, Ideal for POTA, for GRA-7350T, GRA-7350TC

No worries about bending the whip and offering something more rugged

Included adapters means I can use with my JAWS clamps

John VE3IPS

Field-tested and Approved by VE3IPS

Hi Ian,
Gosh it’s been a while since I commented on this thread. Congrats on your purchase of your RHM-12, I’m still laughing at your post with the Barry White music.

The RHM-12 is beautifully finished lol. Out of curiosity where did you order from in Japan?

I must admit when the gentleman in Rocket Radio asked me about getting the 80/160 coil I did smile and decline. Will be interesting to know if you make any QSOs.

Can I also ask what length counterpoise wire you used on 40m to get such low SWR?

73
Steve MW0SAW

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That looks mega. Very similar to the Diamond RHM-12 from the snaps of it. Made in Formosa? Do they have an online shop and are they IOSS-friendly?

Interested to see how you get on with it!

I forget the exact name now, it was something like Mugen Taisen. I had to order via a proxy but did save a fair chunk over buying from Wimo et al.

It really is wonderfully machined and finished. I haven’t tried 160m yet, I will have to get a serious case of strong gout (not 80m band gout, far worse), or maybe buy a racing pigeon or something along those lines. I wouldn’t dare try 160m otherwise.

80m I heard that net so if I had pulled out that delicious little Yaesu FT-891 and hosed the 80m band with a quasar’s worth of Watts that only the buxom 891 can deliver - like Pluto fetching Mickey Mouse’s morning newspaper and slippers - then I might have made some QSO’s!

I used 3 x 10m lengths of wire. Nothing fancy, 24 AWG I think, crimped to spades.

The RHM-12 is getting the slipper soon though. I’ll take the 891 out on a POTA and give it some welly. Stand by yer mics! :saluting_face:

Better yet, I’ll get one of those Diamond roof rack mounts and strap Barry on to an Austin Maestro Countryman for a bit of snazzy /M while everyone else muddles with an ATAS! :heart_eyes:

73

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