Technical info.
A proposed QSO design by Jan
VK3NOV.
How Does A G5rv Work / Not Work??
For those who haven’t heard a G5RV consists of a 102
ft "dipole" fed with 300 ohm feeder (28 feet). Operation
is possible on 80metres through to 10 meters with an ATU – but
you can also squeeze 160m and 6m out if you try hard enough.
3.5Mhz – Each half of the dipole is used and around 17ft
of the feeder, functioning as a slightly folded up ½ wave dipole
7Mhz – Flat top is used along with 16 ft of the feeder –
this time as a partially folded "2 ½ waves in phase"
10 Mhz – two half waves in phase
14 Mhz – This is the band for which the antenna is truly
resonant as a three-half-wave long centre fed antenna
18 Mhz - Two full waves fed in phase
21 Mhz – long wire of five half-waves
24 Mhz – again a long wire of five-half-waves
28 Mhz – two "long wire" antenna, each of three
half-waves fed in phase.
So there you have it. Some people hate the G5RV, others swear by
it. You can read technical articles saying that any wire fed with
300 ohm ribbon will tune with an atu and the G5RV is not a multi-band
antenna at all, and just has 20 metre coverage. Personally I have
used many G5RV antenna’s and had lots of fun – so who cares what
the experts say! An antenna that radiates on all bands, tuning easily
with an ATU, costing less then $20 to build and taking minimal time
to construct has to be worth a try. 73 Phil vk3yb
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Connecting
Dc Power To A Yaesu Ft470 Handheld.
By John L Wickham VK3ZK
If you want to run a handheld of the same type as the
Yaesu FT-470 as a home base affair, and you are sick and tired of
the restrictions imposed by the charge capacity of the NiCd battery
pack, there is a way out if you have a dry-cell battery holder that
you are not using.
Observing the diagram , with a screwdriver open the dry-cell holder
and drill a hole in each half near the power connector tab. Place
a screw into both holes, mount an eye terminal onto each screw and
fasten with a suitable nut. Rotate the eye terminals so that their
tabs place sufficient pressure on the power connector tab and fully
tighten each nut. The object is to get a good electrical connection
as possible.
The power connector tabs appear to be made of aluminium, which
you cannot solder too, unless you have a special kind of solder.
Another eye terminal on the other side of the screw will permit
the connection of a lead to a power supply.
(Editors Comment. As with any installation incorrect operation
can damage your transceiver. Ensure you check the operating voltage
of your handheld and, if necessary install the appropriate regulator.
To save that sinking feeling fuses and a reverse protection diode
are also a very good idea. Proceed with caution – it is easier to
get the smoke out of the radio then to put it back in!)
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EXCITING NEW
CALIFORNIAN IRLP NODE
(by John L Wickham VK3ZK)
There is a new Californian
IRLP node, which covers the Sacremento area and surrounding districts
in Northern California. You will usually find yourself involved
in round table QSO’s on this node.
The node code number
is: 396
You will require a DTMF
touch-tone keypad system, with DTMF set to on. When entering node
code numbers, they must all be sent, usually in a four digit form.
For example, for the above Californian node, the first three digits
are the node code, or 396. The fourth digit must either be a "0"
or "1". 0 enables the node and 1 disables the node. So, first, enter
the appropriate node code for the node that you want, followed by
either a 0 or a 1.
When finishing your
QSO on a node that you enabled, you must shutdown the node…… Happy
IRLPing!
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HF BAND CONDITIONS
- April 2002
The HF bands
have been quite lively recently. If you get some time I would suggest
having a listen on 10 meters in the mornings for some impressive
stateside stations or on 17 metres in the late afternoons. 20 metres
also
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An FT817
As many of you will have heard or seen on air I purchased
a new radio recently. The radio is an FT817, that has an output
of 5 watts on all modes from 160m through to 70cm. Several months
ago I decided that at some stage I have to get one of these units.
It (supposedly) runs off either 8 AA cells, an internal nicad pack
or external DC. My main reason for one of these units was portable
vhf/uhf/shf operation. Prior to purchasing the ‘817 I had to pack
2 large (ft101 size) radio’s, a mobile for 2m and another 2m set
as the IF for the 1296 gear. This will do all of the above, while
also having hf to play on as well.
The size of this unit is about 14cm across and 21cm high – including
knobs and sockets – so it is very portable.
I had lots of people ask me before hand how I would go with only
5 watts. Well I already have amplifiers for 2m & 70cm – so that’s
not a problem. It is intended to replace the 6 metre base station
and five watts is perfect for driving the 1.2ghz transvertor!. HF
wasn’t the primary reason for getting the unit – but I have had
lots of fun with it anyway! They power difference between 5w and
1Kw equates to 4 S points – both theoretically and in practise.
So if you can hear an S9 station and he has less then a S5 noise
floor with QRM/QRN you stand a good chance of having a contact.
I have had some problems on 80m of an evening due to the high noise
levels.
So how does the radio stack up. One of the features that I liked
was the two antenna sockets – an so239 on the rear and a bnc on
the front. You can select which band you want to use which socket.
In this way I can run 2m & 70cm out the front, either into a
dual band antenna or split them with a diplexer, and 6m + HF out
the rear socket. This has worked out well both from home and mobile.
Forget trying to use the radio with Alkaline cells – you might
as well put your money straight in the bin. This said many people
are making up great internal packs with nicads, lithium and nickel
metal hydride cells. So far I have opted to use a 6Ah gell cell
through the 12v socket. At some stage I will either try the nicad
pack or build up an internal pack of some description. (if anyone
comes across surplus gell cells let me know!).
The radio seems very easy to use, has more memories then you can
ever fill, two vfo’s per band, inbuilt SWR & power meters and
most other big rig features. All in all I think it is excellent.
When I travel now rather then taking 2m/70cm fm in my case I will
be able to take HF, 6m, 2m & 70cm all mode for around the same
size – what more can I say!
It is very interesting to see comments on the internet from long
time amateurs on the internet who are having more fun on AR since
they have had this set then at any time in the last 20 years – and
I would put it all down to the number of bands and modes you can
put in a radio that can fit in you glovebox and run off two torch
batteries. Where shall we go today???
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Beacons
The beacon projects are nearly finished, we will have a 23cm beacon
on 1296.532 running about 5 watts.
The 2304.532 beacon will run around 10 watts due to the greater
path attenuation at this frequency.
All the beacons will be using ovenised oscillators to keep the
signal stable, 100hz drift at 10 Mhz 3D 2.4khz drift at 2400 , the
crystal references will be kept at 50 degrees Celsius using clip
on Murata heater units.
The beacons are to be mounted on a water storage tank located at
Bunarong Park, which is located in Frankston, this site will cover
most of Melboure with ease.
Antennas for 1296 will most likely be corner reflector types in
a
stacked arrangement to keep the beamwidth aimed at the horizon,
2403 could also be corner reflector types or even a small dish aimed
to the west and a waveguide vertical antenna for local signals.
Peter VK3KCG
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VHF
Gain
Over the Christmas break I was mentioned to Rex VK7MO
that I had been able to hear him on 2m SSB but not work him – and
yet a nearby amateur was working him on and off for several hours.
"he probably has 25db more gain then you though Phil",
was the answer. Now 25db is significant in anyones terms. Time to
start thinking about more gain. You can’’t work them if you can’t
hear them is a very true statement, so that is obviously the place
to start.
A well designed 6 el yagi will give 9.1dbd gain. The other "local"
station would have been using a bay of four yagi’s – probably of
14 elements. A single 14 el yagi has around 13.6 dbd. A stack of
four theoretically gives an extra 5.6 dbd, but we are going to loose
around 0.18dbd in the phasing – so we will settle on 19dbd. So we
have a handy 10db improvement already.
Why stacked? Figure one show’s gain verses boomlentgh
for a 2m yagi’s. You will note that the "bang for boom"
is in the 5 – 14 dbd area – after that you need a lot of metal to
get gain. The graph stops at a 37 metre boom – and we are yet to
reach 19db! 
Lets now through a pre-amp into the equation. The data I have handy
is for a vk5 preamp. Now the easiest option is to mount it in the
shack. You can expect around 5.2db improvement from a VK5 Preamp
in the shack. Putting the same preamp at the antenna, and assuming
3db cable loss, will give 8dbd improvement! To get the same improvement
over my 6 el yagi I would need either a bay of four 10 element yagi’s
or or a single 30 element yagi on a 21 metre boom!
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IRLP
stands for the Internet Radio Linking Project.
The aim of this project is to link radio systems separated by long
distance without the use of expensive leased lines, satellites,
or controllers.
The IRLP uses Voice-Over-IP software and the power of the Internet
to link your radio site to the world.
The system uses its own custom interface board and software suite
which makes interfacing your radio system to the world simple and
cost effective.
The IRLP runs a large network of dedicated servers and nodes to
offer the very best in voice communications.
The heart of the IRLP is its Amateur Radio network which reaches
hundreds of towns and cities across North America and the World,
linking them all with a full dynamic range, telephone quailty sound.
IRLP Nodes
Now Active! ( Feb. 2002)
Try These IRLP Nodes On VK3RGL
600 VK2RBM Sydney NSW
601 VK2RMP WollongongNSW
603 VK2RMR Riverview NSW
604 VK2RTZ Newcastle NSW
605 VK2RCZ Sydney NSW
606 VK2RAG Gosford NSW
610 VK6RNC Perth W.A.
620 VK6RFM Fremantle W.A.
621 VK2TTA Wahroonga NSW
622 VK2RIC Lismore NSW
626 VK2WAG Wagga NSW
630 VK3RGL Melbourne VIC
631 VK3HEG Ballarat VIC
632 VK3WRM Merbein VIC
633 VK3RPU Arthur™s Seat VIC
635 VK3RMH Melbourne VIC
639 VK3JED Experimental VIC
640 VK4BAB Ipswich QLD
648 VK4RCA Cairns QLD
650 VK5UJ Adelaide SA
660 VK6AMS Karratha W.A.
661 VK6RAL Albany WA
670 VK7AX Ulverstone TAS
680 VK8RTE Darwin NT
690 ZL3TMB Christchurch NZ
700 J73D Roseau Dominica
710 J73CS Roseau Dominica
712 9Z4CG Trinidad
750 9Y4AT Valsayn Trinidad
760 9Y4SRR Trinidad
888 KC4USV McMurdo Station
900 REF900 Vancouver BC
910 REF1 Toronto ON
920 REF2 Denver CO
921 REF921 Raleigh NC
925 REF925 Las Vegas NV
930 REF930 Saskatoon SK
931 REF931 Fredericton NB
940 REF4 YellowknifeNWT
950 REF5 Sydney NSW
100 VE7RHS Vancouver BC
101 VE7URG Vancouver BC
102 VE7RNA Chemainus BC
103 VE7VIC Victoria BC
104 VE7RMT Victoria BC
105 VE7RVN Vernon BC
106 VA7OKN Vernon BC
107 VE7MFS Coquitlam BC
108 VE7TSI Kamloops BC
109 VA7MAR Mackenzie BC
110 VE7RGF Grand Forks BC
111 VE7BHI Port Alberni BC
112 VE7KU Port Alberni BC
113 VA7LPG Nanoose Bay BC
115 VE7REE Penticton BC
116 VE7RAP Comox BC
117 VE7RIA Victoria BC
118 VE7PQD Parksville BC
119 VE7UHF Richmond BC
120 VE6RPT Calgary AB
121 VE7DQC Prince Rupert BC
122 VE6TE Red Deer AB
123 VE6ZV Calgary AB
124 VE6SBR Edmonton AB
125 VE7FFF Prince George BC
126 SARA Province WideAB
127 VA6IRL Lethbridge AB
128 VE6MPR Banff AB
129 VE6WRT Calgary AB
130 VE6TRC Ft. McMurray AB
139 VE7RJZ Invermere BC
140 VA7RDX Vanderhoof BC
141 VE7RTS Kamloops BC
142 VE7RAM Tappe
145 VE6PRR Peace
146 VE6LGL Grand
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