Getting mobile again on the 70MHz (4m) Amateur Band

My 4m Band History To Date

In my radio shack I use an ICOM V200T PMR (Private Mobile Radio) rig, putting out around 30W, for my 70MHz or 4m radio activity. I have a professionally manufactured Jaybeam folded dipole above the roof line as an aerial. It is particularly good as it comes complete with a balun and is very well manufactured. I think I purchased the aerial in 1990 - and it has served me well ever since.

I have other PMR rigs in the cupboard - as I used to be very active and enjoyed converting many of them to the Amateur bands. I started using the 4m band in 1989 using a crystal controlled Telefunken radio which I converted from a German Fire Engine - as they were moving away from crystals and on to VFOs (Variable Frequency Oscillators).

It has, however, been about 4 years since I have had a 4m transceiver, or 'rig', in the car and, as the band seems to be getting more popular in this part of the UK once again, I thought it was time to put that right!

Of course, the one 4m remote-head rig I already owned was limited to 20W and had an annoying 90 second time-out timer, which I could not reprogram, so I wanted to use something with a bit more power out! I still have my Pye 4m amplifier but I wanted to cut down on space and wiring in the car - especially as a modern car can be less roomy for all that gear.

A Solution For Mobile Operating

In the UK it is possible to purchase a 'Quad Band' transceiver covering 4 Amateur Bands: 6m, 4m, 2m and 70cm. I purchased mine from the Martin Lynch Group in Staines, London.

This gave me a remote head option capable of running up to 50W of power out to the aerial. Such power would be just right for mobile operation!

It also means that I can occasionally use the 6m band from the car. I already have access to 2m & 70cm band (analogue & digital) from my ICOM ID5100E in the car. You can see the head unit of the ID5100E above the corresponding head unit of the Quad-Band radio in the photo above. This means both radios are very easy to operate from the driving position.

Now, how to power two radios from one heavy-duty socket in the boot of the car ('trunk' for my Stateside readers!) in a safe manner? Well, I am a great supporter of West Mountain Radio products and PowerPoles, so the top photo shows you the fused system I use to accommodate two radios running at the same time. 

The second photo shows the unit in situ, next to the main unit for the ICOM ID5100E radio. You can see the 12v socket clearly feeding the RigRunner. It works a treat!

Here you can see the 4m aerial situated at the back of my car. It is centre loaded, to make the physical height of the aerial smaller whilst maintaining the same electrical length. It works incredibly well!

I have already worked a few stations whilst travelling around Kent and I expect to work a more over the coming weeks.

Here you can see the 4m aerial on the left & the dual-band 2m/70cm aerial on the right - at the rear of my car.

Hope you found that interesting?

More later!

Best 73 de John G0GCQ

First Dry Run of Portable HF Station

Putting it all together in the rear garden

9m tall Prowhip aerial erected in rear garden ~ tunes on all the Amateur HF ('Short Wave') bands.

Solar panels charging sealed lead acid battery ~ Yaesu FT450D HF radio on white folding table.  

This is my 6-year old sealed lead acid battery ~ used as a spare as the leisure battery is being charged.

The solar panels are working really well ~ allowing me to run 100 Watts output from the radio. The battery is being topped-up as it is being charged at 40 amps via the solar panels. 

Front view ~ note aerial coaxial cable off to the vertical antenna. Cable is 24 feet long, which helps with the tuning process for the vertical aerial on Amateur Radio HF bands.

Yaesu FT-450D radio ~ using a Heil Hand Mic for good audio response & driving of the rig (to get high power output ~ closer to 90W on peaks).

Even though the bands were not very good, due to a recent solar flare that knocked out HF communication to some extent, the radio did pick-up many Italian & German Radio Amateur Stations.

Getting everything ready for portable HF operating ~ Part 2

Vertical Aerial

The Prowhip vertical aerial that I use is based on a fibreglass fishing pole which is less than 1.3m collapsed and 9m extended. Link HERE.

The aerial wire, shown here in red, travels up the fibreglass pole as you extend it to its fullest length. The wire is captured at the tip end, so no threading required!

At the bottom of the aerial you can see an UNUN ~ which allows an unbalanced piece of wire, as shown here in red, to join with a length of 50 Ohm coaxial cable to the radio, without the signal from the radio feeding straight back & frying it. This way, the aerial can be electrically tuned ('cut' to length electrically) using an aerial tuner ~ allowing the maximum signal to get out into the ether and around the globe :-)

Here, at another location from my own, you can see the vertical aerial fully extended ~ 9m ~ mounted on the aluminium post (shown behind the aerial in the photo just above this one). The coaxial cable feeds from the bottom of the UNUN to the rear of the radio.

Yesterday, at this location, I was able to tune the radio on all the HF ('Shortwave Bands' = High Frequency) bands that we can use, including the additional 6m band (50MHz) that we have access to here in the UK.

Stations worked included one in the Azores on the 20m (14MHz) band, which was not particularly 'alive' as conditions were electrically noisy (recent Solar Flares).

I am very happy with this aerial & await using it further this Summer :-)

Yaesu FT-450D HF Transceiver

This is the transceiver that I intend to use whilst out and about working HF portable. It is a very good (smallish) size, whilst maintaining good ergonomics, power and facilities. The internal tuner works very well with the vertical aerial mentioned in part 1.

I will be writing more about this little gem another time.

That's it for now :-)

73 de John G0GCQ

Prowhip Vertical HF Portable Aerial

https://www.prowhipantennas.co.uk/index.php?option=com_virtuemart&view=productdetails&virtuemart_product_id=54&virtuemart_category_id=6

Using the lower radio bands ('Shortwave Bands') from a portable location takes some planning. You obviously need a radio, but you also need a lightweight, easy to erect and take down, portable and efficient aerial. That aerial also needs to be able to electrically tune to the several 'bands' that we Radio Amateurs use.

I could have made a similar aerial but, after much research, I found that I would not be saving any money & the 9m vertical aerial from Prowhip is tried and tested.

I shall be posting some photos later and give you a 'user's view' of how well the aerial works - although, on first testing, it seems to be very efficient & effective.

73 de John

Long Time No Post

Crumbs! I forgot I had this blog!

Luckily, as I am about to start High Frequency (HF) mobile working as a Radio Amateur, I can use this blog as a record of my experiences ☺

I have recently joined the Worked All Britain Award Group, where I will be working HF ('Shortwave Bands') from different locations in Kent & Sussex, trying to cover as many 'squares', based on the Ordnance Survey mapping system in the UK, as I can. Some of them are quite rare - as nobody usually lives there or they are very difficult to reach.

I intend to start blogging about the equipment I will be using: the radio, the aerial, the power source and the solar power kit. I will be taking photos and videos  to show you how I get on.

Until then - Best 73 de G0GCQ

Winterising Aerials For The Harsh Weather Ahead

John (M1FEL) and I, a week ago, were taking down the main aerial pole in order to re-attach the full-size Windom HF Aerial ~ as the rope had finally perished.  It was last checked a year ago!

The main HF Windom attaches to the pole seen on the right-hand side

I took the opportunity to winterise the folded 4m band (70MHz) dipole, which you can see reaching out to the left of the main HF pole, to make sure that the internal balun would not see any ingress of water.  All the connections were great from last year but, to make sure, I replaced the rubberised self-amalgamating tape and cable ties.  At the same time, I attached a stainless steel 'Discone' aerial on top of the main HF pole.  Now I can hear the controller (and not just the aircraft overhead) at Lydd Airport & also at Laschenden (Headcorn) aerodrome.  Great improvement!


If you notice, there are other poles sticking up above the small flat roof that my wife & I have.  Looking at the white fibreglass aerial 'nearest' the TV aerial on the chimney, you can see my main 2m (145MHz) & 70cms (433MHz) aerial: 

X510HDN Base Antenna
Specifications:
Band:	2m/70cm
Element Phasing:	3-5/8l/8-5/8l
Gain (dB):	8.3/11.7
Watts:	330 (2m) / 250 (70cm)
Connector:	Type-N
Weight:	5 lbs.
Length:	17.2'
Max Wind Resistance:	90 MPH

It is really an effective aerial and the coverage is phenomenal from up here!  I am really pleased with this.

X510HDN Base Antenna is the white 'stick' on the right hand side.

The pole to the left of the X510HDN holds a 10m (28>29MHz) fibreglass aerial for DX and Ground Wave working.  When conditions are right, I use this aerial for 10m FM DX (long distance) contacts.  Very efficient, with no measurable reflective power ~ so all power from the radio is effectively radiated from the aerial itself.  All feeder cable to my aerials are 'top-notch' military UHF (Ultra High Frequency) 'spec' ~ which is overkill for the 10m band, but there is minimal loss through the cable!

Finally, the pole on the left-hand side of the photo above shows a 3-element 6m (50MHz) horizontal beam, on top of a rotator, allowing me to turn the aerial to face DX stations around the World.  Above it is a V2000A Tri-band Base Antenna:

Specifications:
Bands:	6m/2m/70cm
Frequency (MHz):	52-54/144-148/440-450
Gain:	2.15dBi/6.2dB/8.4dB
Impedance (nominal):	50W
VSWR:	1.5:1 (typical)
Power Rating:	150 watts
Element Phasing:	1/2l/2-5/8l/4-5/8l
Max Wind Rating:	112 m.p.h.
Mast Dia. Acceptance:	1.2 to 2.4 inches
Length/Weight	8.3 ft./2.6 lbs.
Connector:	SO-239 Female

This, again, is a very efficient aerial ~ one that I use for 'local' nattering on 6m / 2m / 70cms!

Hanging just this side of the Kent Cobnut Tree is the white centre balun of the HF Windom Aerial.

The other end of the Windom aerial is held aloft by the use of an ex-military high-grade aluminium telescopic mast.

The telescopic pole can be seen extended just beyond the white reclining seat.

You can see the radiating element, the vertical cable running down from the large white balun held aloft, running towards the pump house and then into the main property.  High-grade coaxial cable, again, but the distance from the 'Shack' (Radio Room) to the main feed point is only 30 feet. Nothing for the HF ('Short Wave') bands!


So there we have it!  Ready for the Winter ahead!  Here's hoping for some choice contacts on the Amateur Radio bands.

Change of Aerial and repainting mobile mount

A couple of days ago I received my new Diamond NR-790 Mobile aerial (Antenna for my USA readers) to replace the one I borrowed from my friend John (M1FEL).

Diamond NR-790 on car

You can see that this is the Mark II model ~ now using two heavy-weight closed coils.  The 2m band (145 MHz) sees the aerial as a 6/8th wave device (giving 3.7 dBi @ maximum of 300W power out of the radio) whilst the 70cms band (433 MHz) identifies the aerial as 3*5/8th wave device (giving 6.4 dBi @ maximum of 250W power out of the radio).  The aerial is able to handle more than I require, but it is substantially made and has already given fantastic results (see below).

The base below the black 'collar' is much improved

The photo above shows the lower part of the aerial.  Between the mount, i.e. bottom of the aerial, and the first black collar is an important part of this aerial's success: it is a built-in 'ground-plane' ~ ensuring that the aerial is really efficient when it comes to 'matching' the frequency in use.  This section is much larger than the Mark I version ~ probably to handle the extra power ~ but also because the matching has been improved.  The aerial performs as least as well as the Mark I, maybe better?

Painted aerial mount

If you look at an earlier post, you can see that the aerial mount had to be modified ~ leaving it a mixture of black & silver, with a touch of bronze!  I'm not usually worried about looks but, on this occasion, I thought I would paint it all black, using enamel bought from a local shop.

Needless to say, they did not have black!  Henry Ford would be turning in his grave, I thought, but then I saw a pot of red enamel.  The rest you can see for yourself!  I think it looks better ~ even though I have to clean the red enamel off the wire later!

As for the efficiency of the aerial?  Using 5 Watts of power from the radio, I can talk for miles on 2m (145MHz band) ~ not using a repeater I quickly add ~ and I had a similar reaction when using 5W on 70cms (433MHz band), despite going into dips, under tunnels of trees, etc.  Quite amazing!

John (M1FEL) and I will continue to carry out tests on the efficiency of the aerial over the next few days.  Our test for tomorrow will be to see how far we can work each other using 5W on 433.375MHz.  

More anon............ so watch this space!

Adapting the aerial mount on the car

The trip up to South London, from the Kent / East Sussex Border, in the new car on Friday was fine ~ but I noticed that the (usually reliable) aerial mount (antenna for our American friends) was not able to keep the aerial vertical.  It had that slightly 'swept back' look about it.

Adapted Mount

Luckily for me, that kind Radio Amateur John (M1FEL), who lives nearly 1/4-mile from me, has a grinder, drill and a selection of new BA bolts.  You can see that we removed the central locknut and knurled wheel affair and, instead, used a couple of bolts.  The top bolt stops the bracket from rotating (Left <> Right in the photo), which was the main problem, and the central bolt stops the bracket from coming apart.

'Inside' of the bracket

The aerial I am using, you may recall from a previous blog, is the Diamond dual-band NR-790.  This is an excellent aerial ~ allowing me to work John over 50 miles simplex on 145.375MHz (2 metre band) despite great lumps of chalk (including Wrotham Hill) in the way! An excellent piece of kit!  All I need to do now is paint the exposed metal matt black ~ probably Humbrol enamel.

Radio fitted in 'bin' below 12v supply

The radio was, quite simply, the easiest to fit in a long while. Conveniently, the estate car has what I can only describe as 'bins' either side of the tailgate.  The one on the nearside has ample room for the radio (good for circulation & cooling qualities)  ~ benefiting from the cigarette-lighter socket (rated at 20 Amps) above.

Offside ~ showing aerial cable

The other bin is not being used for any radio gear!  The photo above, however, does show you how the aerial cable, mostly hidden underneath the boot space close to the spare wheel, exits the car and runs up the tailgate channel ~ eventually meeting the bracket.

Radio remote head & microphone

The photo above shows the remote radio head in position under the Radio / CD / iPod controller.  You can see the storage position of the Bluetooth headset.  This configuration means that there is only one wire visible from the back of the car to the remote head.  Quite neat!

The rig ~ showing the local 'natter' frequency in MHz

If you look at the above photo closely, where the Bluetooth headset docks with the remote head (just where it says 'Dual'), you can see the blue light on the Bluetooth headset.  That is showing that it is fully charged.  The good thing is, even when the radio is turned off, the Bluetooth headset continues to be charged ~ showing a red LED when doing so.  Clever, eh?  The headset has power for just over 3 hours continual use.  Good enough for me!

'Bumper' sticker from the States

So I am steadily getting the car the way I want it.  Till next time dear friends!

The new car arrives!

So ~ the new car has arrived!  Finally, after leaving the garage in Ashford, I arrived home at 11am this morning.

I am very pleased with the car.  It is the new Fabia Estate variant ~ the 105bhp 1.6 Turbo diesel 'straight-4' engine ~ made in the Polish factory two weeks ago!

They have improved the on-board computer & the display (it was already excellent) and also the radio / CD / iPod player display.  I like the fact that I can fully control the iPod from the radio itself ~ music-wise, that is.

The engine is quite quiet, very economical and, best of all, is incredibly efficient!  Driving around Ashford this morning registered 58.8 mpg!  It should be around 65 mpg at least on a longer journey ~ great!

My friend John (M1FEL for those Radio Hams amongst you) kindly took all these photos for me!  We then 'hatched a plan'.  How long could we wait before putting in the Ham Radio 'rig' and attach the aerial?  We planned for after lunch!

Then the rain came down in buckets ................

It didn't put us off!

The remote 'head' for the radio, which is fitted in the boot & uses the 20 Amp 12v socket at the back.  All fully fused, etc., drawing only 12 amps on full power.  This is fitted on a small metal bracket, thanks once again to John (M1FEL).  The clip to the bottom left-hand side of the 'head' is the recharging clip for the Bluetooth headset.

As it was still tipping down with rain, you can see that I am wearing my 100% waterproof jacket ~ but the important bit (really!!) is that I am wearing the Bluetooth headphone/microphone.  This is totally 'hands free' and very safe!

You can see that we fitted the aerial (a Diamond dual-band aerial for 2m & 70cms bands) ~ a mere 1.4m tall ~ works well!  Thanks to John (M1FEL) who lent me his aerial as it performed better than my (shorter) one.  Who says size doesn't matter?

Everything is working well!  Great!

My grateful thanks to John, of course, without which I would not have the radio 'up and running' within 4 hours of getting the new car back home!

Until next time ............