Questions and Answers
How far will my HF radio transmit??
The short answer is from 20-20000km - I will offer an answer that relates to Aussie 4WD Networks-It is not an exact science though.
You may notice that most of the 4WD networks use a channel close to 8000Khz (8 Mhz) as their main frequency and 5000Khz (5MHz) as their secondary frequency. There is a reason for this --- 8 Mhz is a "good all round" channel during daylight hours, it will work up to about 30 km via groundwave and from 300-1000km via skywave. As for 5Mhz, this tends to be used for shorter skywave distances (Say 200-700 Km)-normally in the early morning or early evening. Note that you will normally have a " black hole" in the transmission range between 30km-200km. This hole is where the groundwave can't reach, and the skywave bounces straight over the top of you.
Most networks also have a 14Mhz channel--Not really practical for use at night but will usually work well from 1500-3000Km skywave during the middle of the day.
This is as a guide only-There are a lot of variables when it comes to HF communications...I recommend that you do some of your own homework to fully understand HF radio systems.
Which radio should I buy, Codan or Barrett??--What Model would suit me??
Barrett and Codan are both well built Aussie radios--It really is personal preference-You will, however, pay about 15% more for an equivalent Codan radio, purely because the Codan name is a little more popular.-All dates below are an approximate guide only.
Barrett Model Timeline:
~SB 220/225 1980-1990 -12 channel crystal locked radio.
~SB 250 1987-1993 - 250 channel with optional selcall-Optional telcall available on radios fitted with Ver. 4 or 5 firmware.
~BC 550 1993-1997 - 500 channel with selcall/telcall etc.
~BC 950 1997-2003 - 400 Channels, although the 950 has similar styling to the 550, it has very different internal hardware and added functionality.
~2050 2003-Current (As of 2020) - Easy to use a radio with pretty much all the bells and whistles.
~4050 2019-Current - A "SDR" (Software Defined Radio) with a large touch screen on the front panel - This front panel can even be extended to your IOS/Android/Microsoft device via the wifi adapter. One nice feature is the micro USB socket on the bottom of the handset. If the end user requires a channel profile alteration etc, the dealer can email through an updated profile which the customer can then upload directly into the handset.
Codan Model Timeline:
~6924/8121 "Lunchbox" Radio 1975-1985. - These popular 50-watt radios had a built in tuner, so basically, all you needed was a piece of wire to throw over a tree as an antenna / then "Tune Up" and you're ready to go. The early model had a few reliability problems, but the 6924 MKII and 8121(Marine version) were quite good.
~7727/6801/7515 and variants 1975-1985 - Normally a 10 channel/100W Crystal locked radio-The 7515 was a 6 channel/50W radio.
~8525A/B 1985-1992 - 99 channel EPROM programmable radio with optional selcall.
~8727 1985-1992 - 10 Channel Crystal locked radio with similar cosmetic styling to the 8525-No Selcall option.
~8528 1989-1995 - 400 channel with selcall/telcall--These radios are still sought after.-Amateur and TXE options available.
~X2 1990-2000 - Extremely well built "PC Programmable" 10 channel radio-No selcall option.
~9313/9480 1989-1994 - Basically a 15 channel version of the 8528 - Selcall only. The 9480 had the LSB option.-Generally these radios can be easily upgraded to a 8528 if you have access to a 8528 keypad & EPROM.
~9323/9360 1993-2003 - 400 channel with selcall/telcall etc. Widely considered in radio circles as the best 4WD HF radio ever built--Still very popular.
~9780 15 channel version of the 9323/9360.
~NGT 2001-2015 - Pretty much all the bells and whistles--Uses a "Mobile Phone" style of microphone with all operations made directly from the handset
~Envoy (X1/X2) 2013 - Current - A "SDR" (Software Defined Radio) with pretty much all the bells and whistles - Also uses a "Mobile Phone" style of mic / handset vaguely similar to the NGT. One nice feature of the Codan Envoy is the micro USB socket on the bottom of the handset. If the end user requires a channel profile alteration etc, the dealer can email through an updated profile which the customer can then upload directly into the handset.
What is a "Local" and what is a "Remote" head radio?
A "Local" radio is an "all in one" unit, whereby the front control panel and main radio transmitter box are one complete unit. This style of radio is quite popular for marine and home base use, but can sometimes be a little impractical for mobile 4WD use.
A "Remote head" radio has a relatively small control head, which attaches to the main transmitter box via an interface cable. This allows you to tuck the larg-ish main transmitter box under the seat etc, and mount the head on the dashboard/console etc.
Pretty much all Barrett and Codan models can be bought in either configuration.
What style of an antenna should I use?
There are two main styles of mobile antennas available-
Autotune and Multitap.
An Autotune basically does what the name implies--It automatically tunes itself to suit the frequency selected on the radio.
Advantage: -Makes life easy when swapping frequencies.
Disadvantage: -High Cost / Generally has to be reconditioned every 5 yrs or so.
A Multitap has to have the "wander lead" moved each time you change frequency.
Advantage: Low cost / Reliable-No servicing required
Disadvantage: Limits the amount of frequencies available on the radio / Have to manually change aerial tap.
Popular Models of autotunes:
Codan 8558--Requires an interface box or circuit board to operate---These antennas are pretty much at the end of their useful life---Not recommended.
Codan 9350 -Very popular--Will plug straight into 8525A/B, 8528, 9323, X2, NGT, & Envoy -- Note that the NGT uses a different antenna interface cable.--There are a few versions of these antennas (A to G-prefix), don't worry too much about the prefix, as long as it has been serviced over the last few years it will of had most of the upgrades anyway.
Codan 3040 - This antenna uses an electronic tuner rather than a stepper motor to drive the antenna. - The electrical connections are identical to the 9350, so it will happily work with the 85xx, 93xx, NGT, & Envoy series of radios. Note that although the stud on top of the autotuner has a 14mm thread, the spring supplied with the 3040 steps down to 12mm for the actual whip mount.
Codan 3042 - This system uses an electronic tuner similar to the 3040 matched up with a remote antenna whip - The electrical connections for the control cable are identical to the 9350, so it will happily work with the 85xx, 93xx, NGT & Envoy series of radios - Note that a "N Type" coaxial connector rather than the standard UHF connector is used on this system.
Codan 3046 - This system is a random length long wire (Base station / Marine) tuner similar in functionality to the Codan 9103 - The electrical connections for the control cable are identical to the 9350, so it will happily work with the 85xx, 93xx, NGT & Envoy series of radios - Note that a "N Type" coaxial connector rather than the standard UHF connector is used on this system.
Barrett 510/910 -Very popular---Just ensure that you get one with the mid to dark grey casing. The very early model 510 (off-white colour) has a tendency for the outer casing to crack.
Barrett 2019 -New- This very robust antenna, is quite sleek looking.---It can also be supplied with an internal GPS antenna/receiver. Note that although 2019 uses a different control lead to the 510/910, it is still "Plug and Play" compatible with the Barrett 530, 550, 930, 950, 2030, 2050 & 4050
What are Selcall, Telcall, Pagecall & GPS Call?
Selcall is a 4 digit calling system between radios:
When you sign up with a network, you will be given a 4 digit selcall number (normally the same 4 digit number as your callsign). Basically it's a signaling system, whereby you can call a base station or another network member. When the receiving station "gets a hit" on its selcall number, it transmits a short "Revertive Tone" across the channel, so that station sending the selcall knows that the receiving station has received the selcall. The radio that receives the selcall also starts "ringing" inside the car, and displays the selcall number of calling station.
The selcall system is widely used on all radio networks. Nowadays it is pretty much essential that you buy a radio with this option if it is to be used as a Land Mobile system (ie. fitted to your 4WD) .
Telcall is the ability to make outgoing phone calls from your HF Radio.
If your network supports telcall, you will be asked if you wish to use telephone interconnect when you sign up. This will allow you to make direct dial telephone calls via your HF radio to any Australian landline or mobile, 24 hrs a day. Call charges vary between HF Networks. Some networks offer a prepaid pay as you go system, and some have a fixed annual fee for unlimited calls. Note that Telcalls are generally restricted to about 6 minutes.
Pagecall is the ability to send and receive a short 64 Character message with another HF transceiver
Some Networks use this feature to allow you to send an SMS to a mobile phone or allow you to receive a message via an App or Email
GPS call is the ability to send and receive your GPS position with another HF Transceiver
Some network allow you log your GPS position which family and friends can access via an APP or webpage
Popular HF Network operators within Australia:
Aussie HF - Selcall, Telcall, GPS Call via Email, Send SMS, Receive short Emails
Austravel (VMD750) - Selcall, Telcall, GPS Call/tracking via APP , Send SMS, Receive short messages via APP
HF Radio Network (VKE237). - Selcall, Telcall, GPS Call via Email, Send SMS, Receive short Emails
Reids radio Data / Bush Telegraph (VMS469). - Selcall, Telcall
RFDS Network. - Selcall
VKS737 HF Radio Network / HF-Tel. - Selcall, Telcall
Annual license fees vary but range from about $40-150. No licensing test required on a 4WD network, just pay your money and away you go.
My HF radio is not "getting out" in my 4WD Vehicle-What could be the problem?-How can I test my antenna??
Firstly - Don't panic. In my experience, only about 1% of problems are actually bonafide faults within the radio or antenna system.
If I were to break it down, I would say that:
50% would be bad earthing of the antenna-Always earth the antenna base mounting bolt directly to the body of the car.-Dont just rely upon the bull bar mounting bolts as your aerial system earth. Never earth the antenna to the negative terminal of the car battery,
30% would be a faulty coax lead.-Always test for short circuits after fitting the coax connectors.
15% would be a bad power feed-Always use 4-6 mm2 cable, and a physically large 25-30 Amp fuse or circuit breaker.-Do not use a small glass(3AG) or spade fuse.
5% other misc faults.
Here is a little "ballpark" test of your Multi-tap antenna system-This has got me out of trouble many a time:
Set antenna and radio to the frequency you wish to test.-Turn up the radio to about 3/4 volume.
Unscrew coax connector from radio--you should now only hear some low level "hiss".
Plug the middle contact of the coax connector back into the radio-You don't want to push it all the way home-Only the centre pin must be connected, the outer screw thread must be clear from the radio.--Noise level through your speaker should jump dramatically. You should now hear plenty of loud static coming from the radio.
Now here is the important part-Now push the connector all the way home and touch the outer thread on the radio--If all is well, the static should get about 25% louder, if it gets a bit quieter your antenna is not set up properly--If it goes very quiet, you have a short circuit in your antenna or coax system.
This is only a general test only, but it may help you to troubleshoot your problem.
I can't seem to receive anything, All I can hear is "Hash & Noise".
Background "Noise and Hash" is quite normal on a HF radio receiver---The latest model Barrett (2050) & Codan (NGT) both have noise reduction systems which improve things a little, but are not a miracle cure.
If you can only receive a signal from a car basically parked 50 Metres from you, the problem will probably be:
*Short circuit in antenna or coax system. - Common Fault.
*External electronic noise generation--Common culprits are Battery Pulse, Antirust Systems, Cheaper Solar Regulators, and Fridges - All of these devices will need to have a switch fitted in line so they can be turned off while using the HF radio. - Common Fault.
If you can't receive a signal at all from a car parked 50 M from you, you probably have a faulty receiver.
Can you modify my radio to do.....??
Yes, I am happy to do firmware upgrades and other mods which keep the radio within it's ACMA type approval or Ctick specifications(ie keep it all legal for normal 4WD use).
There are some Amateur radio (opt A, TXE etc) options available which take the radio outside this guidelines.---I will need to see a copy of your relevant license if you wish to purchase one of these options....no exceptions!
Can you supply programming software to suit my radio?
I cannot supply radio programming software-It is not freeware, and the radio manufacturers closely guard their copyright of it.
