Mobile/-

portable

radio

Something in radio terms I’ve personally found fun is operating mobile (or at least static mobile..., 'portable from the car'...,) you know!

(Thanks Brian GW0GHF for the 'car'toon above!!)

When I first (finally) obtained my amateur license in 2005 it was the only way I could really get on air as at the time I lived in a flat in Plymouth with no prospect of setting up aerials. So the Mercedes E220 became my mobile shack being set up for VHF with the FT480r and HF with the FT747GX using AMPRO aerials for 20m, 17m and 40m with a fair amount of success as well as 80m (less successful mobile). Occasional 10m operation was fun when conditions were good enough with an old CB aerial, (a Les Wallen ‘Modulator’). Living near Dartmoor at the time offered some good locations to play radio including Roborough Down, ‘the duck pond’ (on the Princetown road above Yelverton) and just above Ashburton (pics below in this case using a 'silver rod' (bought from a radio rally for a fiver!) ground mounted on a spike and lashed to the car tow hitch for HF operation on 20m and 17m with the FT707). Fortunately I had the forethought to take some photos at the time as very often these things are lost to time!!

The move to the cottage at Rozel in Jersey meant being able to erect a limited array of aerials but mobile operation was still fun though mainly on VHF with the locals or the short hop (!?) back into the UK from the Mercedes A140. In fact from the north coast of Jersey I regularly could work mobile through the Dorchester and Torquay 2m repeaters, just occasionally through GB3PL near Callington (when the wind was in the right direction!!).

Getting a Yaesu FTM-10r and the FT857d in the car made things a little more accessible when operating mobile and whilst it’s not a regular occurrence these days it’s nice to have the equipment available for those odd occasions when time permits. Also the 857 is a superb bit of kit giving consistently good results on both HF and VHF when mobile. The FTM-10r is superb having a bluetooth headset (see separate page).

Sirio Performer 5000 for 28MHz is the newest acquisition for 10m mobile operation (though is a CB antenna of course but it is fairly broad banded); costing a bit more than an Ampro for 28MHz but is one of the better antennas available by various accounts. I looked for a 6’ Avanti Moonraker mobile but they’ve not been made for years and the last one I saw advertised was well over £100. Below the 'original' home made mobile mounting bracket fixed to the body of the car at the tailgate opening, its been there since about 2008 and still works well though like 'Triggers broom', its not on its first run of co-ax!! The original Performer was not that easy to tune in for 10m but that just turned out to be the ravages of age and weather on the DV base mount (soon resolved!). I was quite taken with the 'trucker' version of the aerial and it sits well on the car particularly taking into account the height of the mounting.

Mid 2019 and I was able to get another Sirio Performer at 1/3 off the normal price (a new gimmicky 'light up' version had come out and appears beloved of Plymouth taxi drivers!!). This at the time giving highly effective 10 m mobile in both the cars! SO239 mount (with DV mount adapter) fixed through the roof on the A210 and giving a good sturdy mounting! I was going to duplicate the body mount above but never got around to it; this was better in many ways though giving a more even transmission footprint taking the car roof and bodywork into account as a ground plane (though the original corner mount has always worked well for me).

Operating mobile introduces a few specific challenges with set up and operability. Good aerial mounting is essential - I built a bracket on the back of the A140 years ago for a ‘DV’ base mounting which works better than a mag mount for HF though the mag still works fine for VHF (using a 1/2 wave or Watson 5/8 wave and occasionally the huge old 7/8 wave 2m monobander!).

Radio mounting and positioning of course needs to be not only convenient for operation but not distracting or actually physically in the way for when you're driving and should be secure so it can't become a 'projectile' should the worst happen for any reason! The FT857d remote mounting head was fitted to a thin sheet of aluminium fashioned into a right angle mounting bracket thin enough to fit below the car radio and worked well for many years.

A little north coast /m operation and aerial tuning in early 2021 with the Icom IC-7000 whilst I still had the Mercedes A210.

At the time my personalised number plate for the A-Class showing both the Jersey and the France callsign, sadly short lived!!

Final outing for 'Alfred' the A-class, some dabbling on HF with the IC-7000 and then a hot sunny Sunday with the 'backpacker beam and the FT-290R using the car as my portable shack for the 2021 PW 2m QRP contest...., and made no decent contacts at all. Unfortunately a sunny day does not always mean decent lift conditions!

Big change around with cars in 2021 meant the departure of both Mercedes A-class' and stripping out all of the radio gear installed over a number of years (2007 to 2021 I was amazed to realise!). The new Volvo C30 isn't the most amateur radio friendly design it seems but there are always ways aren't there and the FT857d is now installed connected to a glass mount dual band Watson VHF/UHF antenna and a magmount for HF.

The FT857d has the benefit of a remote mounting/separation kit allowing the face plate or head unit to be mounted conveniently, in the Volvo this has been double sided 'gorilla taped' to the centre console nice and securely and linked to the Watson Boom microphone which is mounted above the sun visor (sensitive enough going along that it doesn't even need to be pulled down to mouth level!) and with the PTT switch which also has tuning up/down buttons mounted on the handbrake, it is intended for the gear stick but the Volvo one is just too short and stubby for that to be an option!).

Above the location for the Watson boom microphone in front of the drivers side sun-visor and a (limited) view of the Yaesu FT857d rig mounted under the drivers seat. It looks a little like a 'rats nest' I know but all works fine and it is securely mounted using, would you believe, a strip of Velcro on the mounting bracket to hold it in place behind a cross member below the drivers seat so it cannot move.

The Watson dual band mobile 'on-glass' aerial works well despite no actual metal mounting or ground plane. The external mounting is a heavy duty sticky back pad but over time these can weather and peel off so mastic sealant applied around the glass and mounting junction should keep this weatherproof for the foreseable future hopefully. Internally there is a metal wire counterpoise and a tuning screw on the base of the aerial co-ax connector or mounting. The Aerial includes a helical winding part way up which at high speeds creates some undue wind noise so when not in use the whip can be unscrewed and stored in the boot and the screw thread of the mounting capped off with a rubber 'bung' of the appropriate size to safeguard against the ravages of the weather. Bizarrely a batch of these were delivered to me ages ago, not something I'd ordered and no clues as to what they are for so they went in a drawer BUT they are the perfect size for this and it means I have a ready stock of them in case one should ever get lost!

'Top tech tip'...!' Wet weather made the mounting screw start to deteriorate and the aerial start to come loose on my travels so a smear of aluminium grease to the thread and a small/thin rubber washer at the base of the screw thread mounting that the aerial can be tightened against seems to do the trick to keep everything in good nick, tightly secured and weather resistant.

A quick side note about 'on glass' antenna's! These work on the principle of inductance so in simple terms on transmit the RF is sent down the co-ax to the internal mounting which then radiates the signal through the glass to the externally mounted and tuned for resonance aerial. Receive works effectively the same and gently in reverse; its bound to be a compromise compared to a properly mounted 'real' aerial but it works well enough when you can't or don't want to drill holes in your car's body or the shut lines are just too tight not to damage a co-ax feed to a mag-mount. So I can't help but laugh on a YouTube channel by an American Ham showing how to install one of these (he suggested the silicon/mastic sealant trick!) with so many people commenting with things like 'how do you drill through the glass?' and 'when you remove the aerial how do you fix the hole in the glass thats left behind?!'. I feel inclined to say..., 'DUH!!!' I am often amazed at how dim licensed amateurs can sometimes be but I suppose I'd get in trouble if I said that (I have seen how licensed amateurs fit things like PL259 plugs and the like!!).

So thats the present incarnation of the /M installation, so far so good. In the interior pic above the brown 'roll' is the aerial bag Mum made for me years ago, still going strong, holds 4 or 5 AMPRO HF aerials AND is just the right width to fit between the rear windows behind the back seat headrests when the car parcel shelf is in use. Could almost be made for it!