 |
 |
My Home Page             PORTABLE PLT QRM Site Map MDS975 Home
British Telecom Causes Radio Interference Wipe-Out Radio Interference form BT HomePlug Adapters Broadband by Powerline "BPL" wipes out Radio Reception Power Line Telecoms PLT Obliterates H.F. Radio Mini Site Map MDS975 Home
British Telecom Causes Radio Interference Wipe-Out Radio Interference form BT HomePlug Adapters Broadband by Powerline "BPL" wipes out Radio Reception Power Line Telecoms PLT Obliterates H.F. Radio
|
PORTABLE OPERATING /P
Fancy going portable to
escape the man made electrical QRM and the ever encroaching blight on
the radio spectrum by BT Vision Broadband
by Power Line Adapters - (PLT), HomePlug, and other
disastrous BPL
devices? Well, after viewing Diana Eng's inspiring video (below) I was prompted to look into what's required and so I started compiling a list of ideas which I noted down and then presented on this page in case it may help others: Setting up an HF rig for SOTA by Diana Eng, KC2UHB Here is a superb video article made by Diana Eng KC2UHB. Diana's video shows how to set up an Amateur Radio station for Summits On The Air (SOTA). Her video is also featured in the October issue of the online publication Make Magazine in an article titled 'How-To: Set up an HF portable radio while hiking' Watch the video: MAKE Magazine describes itself as the first magazine devoted entirely to DIY technology projects, it unites, inspires and informs a growing community of resourceful people who undertake amazing projects in their backyards, basements, and garages, see http://makezine.com/ Informational Videos by G3CWI of Sotabeams http://www.sotabeams.co.uk After viewing Diana's video I found these excellent videos too:
Diana Eng, KC2UHB's excellent video prompted me to find out more about what's required for /P. So here is a list of information that I compiled and have presented here in case it can help others too. PORTABLE EQUIPMENT A suitable Transceiver; Appropriate Aerials (h.f. / v.h.f. / u.h.f.); Support poles, Masting, Telescopic fibreglass fishing pole etc; Guy ropes and Pegs; Ground spike; Counterpoise wire(s); Feeder cables; ATU; VSWR meter; Patch Leads; Adapters - e.g. BNC to SMA, BNC to PL259, PL250 to N type or PL259 to SMA etc; Power - often in the form of a sealed lead acid Battery or Batteries or NiMH Battery Pack; Power Cables; Headphones; Morse Key; Tools needed for erecting aerials and adjusting aerial wires etc; Carrying Bag or Case; Map and Compass; Log Book; Check List. Other things: Perhaps something like a picnic table and chair to rest on; GPS / Satellite Navigation; Shelter - parasol / tent / car / van / caravan / motor home etc; suitable clothing - waterproofs, boots, jumper etc. TRANSCEIVER Perhaps the obvious first choice for simple lightweight portable operation might be a handheld transceiver such as a Yaesu FT-60, VX-6, VX-7 or, indeed, any other 'handie'. A handheld is inexpensive, small, lightweight and obviously easily transportable. Handies will often be dual band giving access to 2m and 70cm, but sometimes with the bonus of additional bands such as 6m or 23cm. Apart from only providing access the the VHF and UHF bands, the other limitation of handheld transceivers is that they only provide FM. SSB is far more efficient, especially for DX, and will also consume considerably less power than when operating using FM which is a very important consideration when operating /P in a remote location with a limited power supply. SSB will therefore enable the battery to last much longer. To work SSB a multi mode transceiver will be required, the transceiver will also need to be small and light enough to be carried around. Many small multi-mode protable and mobile transceivers will also give access to the HF bands - escaping the QRM of a populated area!  Yaesu FT-857D multi-mode, multi-band amateur radio transceiver The most popular transceiver for portable operations is possibly the FT-817 a QRP rig by Yaesu. The FT-817 provides 5 watts on HF, 6m, 2m and 70cm. Other mobile radios such as the Yaesu FT-857D, FT-897D and Icom IC-706mkIIg and IC-7200 are a little larger and heavier, of course, but are also attractive transceivers for portable operations. All these rigs offer the HF bands plus 6m, 2m and 70cm (except the IC-7200 which misses 2m and 70cm) and with much higher power capabilities than the FT-817. POWER  Power can be supplied from the car or van battery if working in close proximity to the vehicle, but this might not be the best solution since there is always the possibility of flattening the battery and getting stranded! It's not a good idea to flatten a car battery anyway as this can cause damage. For QRP operation many operators use a compact sealed lead acid battery known as a SLAB. Typically a SLAB will need to have a capacity of around 7 Amp hours to 12 AH to provide enough power for several hours work. The battery is charged at home using a mains charger. Power could also be derived from a pack of high capacity rechargeable NiMH cells, as is demonstrated in the video.  For longer or
higher power use a battery with higher capacity is needed. A
standard car battery is unsuitable for this type of use as it is not
designed to be fully discharged and re-charged repeatedly as this type
of treatment will damage the plates of an ordinary lead acid car
battery, a 'leisure battery' should be used.Leisure Batteries are also known as Marine or Motorhome Batteries and are designed with thicker plates that are more able to withstand being regularly discharged and recharged. Such a battery may have a capacity of around 75 to 110 AH. As with other rechargeable batteries a leisure battery would generally be recharged using a mains recharging system. A true Deep Cycle Battery is more substantial than a leisure battery and are even more able to withstand regular discharge and charge cycles. Polarity: Always take car with the polarity of power leads and connectors when using batteries - a simple rushed mistake can be VERY costly indeed! PORTABLE AERIALS Supports and Poles When operating /P a good lightweight pole or mast may be required to support the aerial. The simplest and most lightweight is probably going to be a telescopic fibreglass fishing pole somewhere between 7 and 10 metres long. The top two or three sections of a fishing will be too thin and flexible to support a substantial aerial such as a Sotabeam or centre of a wire dipole so, for example, a 7m long telescopic fishing pole will support a Sotabeam vhf/uhf aerial at about 4m a.g.l., while a 10 metre long fishing pole will support a Sotabeam vhf/uhf aerial at about 7m a.g.l. , while the full 10m length could be used to support a single vertical wire of a 1/4 wave ground plane antenna for HF work. Other options would include sturdier, but heavier, aluminium or fibreglass telescopic poles or, alternatively sectional swaged poles of either aluminium or fibreglass that may be bought from suppliers such as Sandpiper, Moonraker and other well known amateur radio suppliers. These will be strong enough to support standard type vhf and uhf beam aerials. Spiders or guy rings and guy ropes and pegs that are suitable for the supports being used will also be required. VHF and UHF AERIALS As usual, the convention is that vertical polarisation is generally used for FM while horizontal polarization is adopted for SSB working. Pretty much any typical 2m or 70cm aerial such as a dipole, yagi, ZL Special or 'slim jim' or other vertical etc could be used for portable operations as long as the size and weight can be accommodated. If walking, rather than driving, to a remote location such as a hill top, then a compact, easily dismantled and very lightweight aerial will be appreciated - there are some aerials that are specially designed for this purpose: Sotabeams: Perhaps the most famous lightweight portable aerial system is from Sotabeams - http://www.sotabeams.co.uk - the current version is the SB270 which is a 3 element beam for 2m with 6dBd gain and 6 element beam for 70cm with about 8dBd gain. The SB270 is designed to be mounted on a telescopic fibreglass fishing pole. The SB270 is a superb design that is very well engineered and produced. The SB270 is shown below. Sotabeams also produce a simple lightweight dipole called the Multi Function Dipole MFD for when very light weight portable working is required, without the need for a directional yagi. The MFD is also shown below.   SB270 from Sotabeams
http://www.sotabeams.co.uk  The Sotabeams Multi Function Dipole - MFD http://www.sotabeams.co.uk Sandpiper:
Sandpiper
Aerial
Technology
produce
a
huge
range of aerials, some of which are
especially suitable for portable work. Shown below is the Sandpiper 145
/ 435 Dual Band Yagi with 7.3 dBd gain on 2m and 8.9 dBd on 70cm.
Also shown are the Sandpiper Dual Band Portable and the Dual Band Open Sleeve Dipole:  Sandpiper 145 / 435 Dual Band Yagi http://www.sandpiperaerials.co.uk   Sandpiper Dual Band Portable Yagi and Dual Band Open Sleeve Dipole http://www.sandpiperaerials.co.uk  Lam
Fox
JS270
dual
band
2m
& 70 cms portable yagi aerial
uncannily similar to the Sandpiper yagi (could be made by Sandpiper?) http://www.lamcommunications.net SIMPLE H.F. AERIALS Norcal Doublet: A simple, easy to erect, portable HF antenna might be a doublet aerial, as described by the NORCAL QRP Club. This is a simple aerial fed from an ATU and balun via twin feeder for low loss. As described, the Norcal Doublet is 44 feet long i.e. 22 feet per leg. The Norcal Doublet is made from a length of 4 conductor computer cable, but other methods could be used. The ends could be supported by nearby trees, and/or the centrepiece could be supported by a lightweight fibreglass telescopic pole. If using a telescopic fibreglass fishing pole to support the centre of the aetial, fix the centre of the doublet at the bottom of the top section, or the bottom of the next section down for more stability and guy the pole using light tension so that the pole sections do not collapse.  The Norcal Doublet by Doug Hendricks KI6DS, Jim Duffey KK6MC/5 and Dennis Foster KK5PY  Norcal HF Doublet -
http://www.norcalqrp.org/norcaldoublet.htm
 The wire ends are
connected to the balanced line terminals on the
a.t.u. or to a separate balun Link or Fan Dipole: A lightweight Link Dipole or Fan Dipole could also be suspended with the help of a nice telescopic fibreglass pole, or other support, at its centre. If using a telescopic fibreglass fishing pole fix the centre of the dipole at the bottom of the top section, or the bottom of the next section down for more stability and guy the pole using light tension so that the pole sections do not collapse.  Multi Band Resonant
Link Dipole - very efficient and simple
Long Wire: A fibreglass telescopic fishing pole (Sota Pole) can be used to support a long wire, end fed, aerial. A wire that is a 3/8th wavelength for the lowest frequency of operation can be used as the radiator, fed against a counterpoise wire of the same length run out along the ground. The aerial wire is suspended in an inverted V shape, attached to the pole at the bottom of the top section, or the bottom of the next section down for more stability and guy the pole using light tension so that the pole sections do not collapse.  Sotabeams ( http://www.sotabeams.co.uk ) suggest that a wire of about 9 meters might be sufficient for this type of use. End Fed Half Wave Dipole Allan Copland, GM1SXX very helpfully comments: "....There are many choices and permutations, but in general, dipoles are centre fed at a point of current maximum (and minimum voltage). A normal dipole is current fed but of course can be voltage fed instead. This is what’s done in the End Fed Half Wave Antenna, or Fuchs aerial, where a resonant half wave wire is fed at one end (max voltage / min current) from an L/C tank, against a very short counterpoise wire. The End Fed Half Wave Antenna (EFHWA) is fed at a voltage node via a parallel resonant circuit against a ‘short counterpoise’, it is a favourite of backpackers and outdoor types. It can be considered as a half wave dipole that’s end-fed at a voltage node rather than the current node, as is more usual. This is a very handy arrangement for portable QRP work." EFHWA Link: http://www.aa5tb.com/efha.html W3EDP Antenna  The Tuning capacitor in the AMU can be a 365 - 500pF broadcast type or a miniature version is OK for QRP use. Counterpoise lengths: 3.5 & 7.0Mhz - 17ft ; 14Mhz - 6.5ft ; 28Mhz - none Tuning Unit: Values for coils in the unit, based on a 2 inch former and 16 swg wire: 3.5Mhz 21 turns ; 7.0Mhz 7 turns ; 14.0Mhz - 5 turns. K3HRN Notes: "Some folks have told me the modifications below make the antenna something other than a W3EDP. I can tell you that it works very well with 5 watts. Create a "bundle" of counterpoise wires, 1/4 wave length for each band you will use. Attach the bundle to the tuner in place of the counterpoise pictured above. Be cautious, 1/4 wave length elements can have high RF voltages present, even at QRP power levels. I've been able to work 160-10, including WARC bands with this type of antenna". Off
Centre
Fed
Dipole
(OCFD)
-
Windom Antenna
The "Windom Antenna" was described by Loren G. Windom W8GZ. It could be an ideal wire aerial for use in restricted spaces for multi-band operation. It may also be an good candidate for portable work. It is a wire antenna, similar to a dipole, but unlike a dipole or doublet which is fed at the exact centre, a Windom or Off Centre Fed Dipole, as the name suggests, has the feed point off center. Current versions of the Windom have a balun at the feed point which is fed with coaxial cable. As with all aerials the aerial should be as high as possible. With the feed point at between 20 and 40 feet above ground the typical claimed impedance will be somewhere in the region of 200 Ohms so a 4:1 balun will typically be required. At greater heights, and depending upon the exact position of the feed point, the impedance may be higher and a 5:1 or 6:1 balun might be a better choice although balun losses will be greater. The point at which a Windom is fed in the original design, which used an open wire to feed the aerial, was 15 percent off-centre. The current designs, which are fed with coaxial cable, are typically fed about 33 percent off centre, so one leg is 67 percent of the total length and the other leg is 33 percent of the overall length of the aerial. The bands that are covered depends upon the overall length of the aerial: 11 metres long (approx) should cover 20m, 15m and 10m and the WARC bands with a tuner. 21 metres long (approx) should cover 40m, 20m, 15m and the 10m bands and WARC with a tuner. 41 metres long (approx) should cover 80m, 40m, 20m, 15m and 10m and WARC with a tuner. 80 metres long (approx) should cover 160m, 80m, 40m, 20m, 15m and 10m and WARC with a tuner. Cut the aerial for the lowest band to be used. In imperial measurements using a familiar formula: The longer leg will be 468 divided by the frequency and multiplied by .67 = length in feet The shorter leg will be 468 divided by the frequency and multiplied by .36 = length in feet Given the fairly simple formula it should be quite easy to make an OCFD Windom - however a Windom can be purchased at very reasonable cost commercially, for example from M0CVO at http://m0cvoantennas.webs.com  Delta Loop: Using fibreglass fishing poles (Sota Poles) again. Two 7 metre long poles can be erected in an inverted V shape and used to support a 20 metre delta loop which will be useable on 20m to 10m and also adaptable for use on the 40 metre band. The two aerial wires used are connected directly to a 4:1 balun which is, in turn, connected to an ATU such as the Z-11 Pro or Z-100 via coaxial cable. See this page which shows the W6ZO delta loop to get for the general idea of what will be achieved. The finished aerial will be very much like the commercially available DMV-Pro.  Similarly a vertical aerial for the 14 MHz band would have a vertical radiator approximately 5.5 metres long and for the 18 MHz band the wire for the vertical radiator would be about 3.9 metres long etc. Maybe more ground radial wires could be used for a more affective ground-plane. Non-resonant broadband antenna? Alternatively a non-resonant design could be employed using a 10 metre radiator and 10 metre counterpoise fed to the ATU by a 9:1 unun at the aerial's base - commercial examples are available from GWhip Antenna Products and ProAntennas - similar to the non resonant Comet CHA250B design. This arrangement may not be as efficient as a resonant aerial due to quite considerable power losses on most bands, but at least it could get one on the air from 80m to 10m. (Martin G8JNJ, suggests that a slightly better way to home-brew a broadband HF aerial might be to cut a vertical aerial for about 8.5 MHz, i.e. not a resonant 1/4 wave on any amateur band, but optimised to present a moderate impedance on as many bands as possible. In which case the vertical wire would be about 8.8 metres long, working against the counterpoise, and fed to the a.t.u. via an unun - perhaps 6:1 or 9:1 - this is all open to further research and experimentation! See http://g8jnj.webs.com/currentprojects.htm). G0KYA has also written a couple of interesting pieces about using a 9:1 unun and a length of wire. He found that a wire length of 19.8 metres offered a good compromise for a multi band aerial. Read G0KYA's blog here: http://g0kya.blogspot.com/search/label/antennas Interestingly 2W0SAK of Snowdonia Radio Company (SRC) recommends an antenna wire length of 7.13 metres with their 9:1 unun - or for better efficiency a wire that is 19.8 metres long which would be run out as a horizontal wire. Both the 7.12 m and 19.8 metre lengths should cover the 80m to 10m bands. See http://www.snowdonia-radio-company.co.uk for their X65 Multi antenna and 9:1 Unun. Commercially Available Portable Antennas: Sandpiper Aerial Technology offer a huge range of aerials at a very reasonable cost such as the Sandpiper Buttie Pole or Walkabout MkII and others. Commercially made aerials can be very expensive indeed, but other options might include the TW2010 from Transworld Antennas, The Sigma 5 from Force12 and aerials from SuperAntennas. ProAntennas offer the interesting DMV-Pro and the I-Pro (similar to the Sigma5 and TW2010), or well known GWhip products for example. Many other portable antenna products are available - just check out your local ham radio emporium. I have put some links further down this page too. More Ideas: Field Deployable Antennas by Eric McFadden WD8RIF : http://home.frognet.net/~mcfadden/wd8rif/field-antennas.htm#w3edp A.T.U.  Examples include the LDG Z-11 Pro and LDG Z-100 Pro. Visit the LDG website at: http://www.ldgelectronics.com  Elecraft offer
the very compact T1 autotuner which measurs only 5 x 3 x 1 inches. The T1’s 7-inductor, 7-capacitor L-network provides a wide matching range, and its re-tune time from memory is just 1 to 2 seconds and can be used with any 0.5-W to 20-W transceiver covering bands in the 160-6 m range. This includes kits, home-built rigs, and commercial transceivers such as the FT-817, IC703, Ten-Tec Argonaut, SG2020, etc. More information from http://www.elecraft.com MFJ also produce some very small manual ATUs that are ideal for /P. Examples are the MFJ-901B, MFJ-904H, MFJ-941E, MFJ-945E. http://www.mfjenterprises.com Connectors - Feeder - Cable_- Other things Ensure that the necessary feeders and cables are available along with any adaptors that will be needed such as BNC to SMA, BNC to PL259, PL250 to N type or PL259 to SMA etc. Ground Spike, Counterpoise wires as necessary. Perhaps a VSWR / Power Meter if the a.t.u. does not have one. A Morse Key for CW. The necessary power cables. Log Book. Equipment Check List. Summits On The Air SOTA : http://www.sota.org.uk Line-Lok guy runners for support pole guy ropes by ClamCleats: http://www.clamcleat.com/cleats/cleats.asp?menuid=7 VHF / UHF Antennas SOTA Beams - portable VHF and UHF antennas.telescopic poles and useful amateur radio accessories: http://www.sotabeams.co.uk Sandpiper Aerial Technology offer various 2m, 4m, 6m and 70cms aerials including ZL Special: http://www.sandpiperaerials.co.uk Moonraker offer various aerials for 2m, 4m, 6m and 70cms including ZL Special aerials: http://www.moonrakerukltd.com Homebrew VHF antenna: http://www.vhfman.freeuk.com/radio/antennas.html Portable 2 metre - 145 MHz - Pocket Beam by Richard Price BSc, MSc, GW0VMW : http://mw0idx.co.uk/2mPortPockBeamGW0VMW.html Homebrew horizontally polarized 2 metre halo stack: http://www.kr1st.com/2mhalo.htm Homebrew horizontally polarized 70cms halo stack: http://www.kr1st.com/70cmstack.htm Poles and Supports Tecadi - for heavy duty fibreglass pole sets: http://www.tecadi.de Sandpiper Aerial Technology offer various supports: http://www.sandpiperaerials.co.uk Moonraker - a range of poles and tripods: http://www.moonrakerukltd.com Skyblue Leisure: http://www.skyblueleisure.co.uk/acatalog/Telescopic_Poles.html see: Bowmanarcher on ebay Portable HF Antennas LDG Auto Antenna Tuners + baluns etc: http://www.ldgelectronics.com Norcal Doublet Antenna: http://www.norcalqrp.org/norcaldoublet.htm Sandpiper Aerial Technology offer various portable antenna options: http://www.sandpiperaerials.co.uk Moonraker antennas: http://www.moonrakerukltd.com ProAntennas: http://www.proantennas.co.uk GWhip Antenna Products: http://www.gwhip.co.uk SRC - Snowdonia Radio Company: http://www.snowdonia-radio-company.co.uk ProWhip Antennas: http://www.prowhipantennas.co.uk/ N4JTE Ribbon (fan) Dipole Design: http://n4jte.blogspot.com/2009/04/n4jte-6-band-ribbon-antenna-35.html More ideas on the Antennas 4 page and more links on the links page here and here 4 Metre Transverters Spectrum Communications: http://www.spectrumcomms.co.uk
4 Metre Tranceivers GAREX - A British manufacturing company. Suppliers of transceivers, PMR radios plus Patch Leads, Components, Aerials, and VHF UHF Accessories. http://www.garex.co.uk Cables - Feeder - Patch Leads - Adapters W H Westlake: http://www.whwestlake.co.uk/ Portable Transceivers Yaesu FT-60, VX-6R, FT-817 or FT-857D or FT-897D etc: Yaesu UK: http://www.yaesu.co.uk Yaesu America: http://www.yaesu.com Vertex Standard Japan: http://www.vxstd.com Icom IC-E90, IC-703, IC-706mkIIG, IC-7200 etc: Icom UK: http://www.icomuk.co.uk Icom America: http://www.icomamerica.com Icom Japan: http://www.icom.co.jp Alinco: Alinco UK: http://www.alinco.co.uk Alinco USA: http://www.alinco.com Alinco Japan: http://www.alinco.com Kenwood: Kenwood UK: http://www.kenwood-electronics.co.uk Kenwood USA: http://www.kenwoodusa.com Elecraft: A range of high performance tranceivers: http://www.elecraft.com Portable Power Sealed Lead Acid Batteries and Deep Cycle Leisure Batteries MDS Battery: http://www.mdsbattery.co.uk Alternative Energy Store: http://www.alternativeenergystore.co.uk Tayna: http://www.tayna.co.uk Amateur Radio Dealers See our links page here: Suppliers Tents http://www.singersoutdoors.co.uk http://www.cheaptents.com http://www.worldoftents.co.uk http://www.millets.co.uk http://www.outdoorworld.co.uk http://www.tents-direct.co.uk |
||||||
Amateur Radio Page | My Station | Antennas
/ Aerials | Accessories
| Projects
& Kits | Data
Modes | Information |
QSL
| RSGB
|
|||||||
Mike Smith - MDS975.co.uk © 2003 - 2010
M0MTJ
Subjects covered on this page:
Amateur Radio; Ham Radio; Radio; Transceivers; HF; VHF; UHF; Data Modes; Morse Code; RTTY; PSK31; SSTV; FSTV; Amtor; Sitor
Antennas; Aerials; Cable; Coaxial Cable; Twin Lead; Masts; Poles; Propagation; Computer; PC; USB Computer Interface; Microphone
Loudspeaker; Filters; Noise Reuction; DSP; Digital Signal Processing; Morse Key; SWR ; Inverted L; Inverted V; Dipole; Doublet;