BRIAN SMITH G1EIO : Amateur Radio.

BRIAN SMITH G1EIO
Amateur Radio.

Problems with your Studies

If your doing the

Foundation Course

and you finding it a little hard to understand

then take a look at this

Comic Book

"THE ADVENTURES

OF ZACK AND MACX"

BY ICOM

Download it

http://www.freewebs.com/g1eioxyz/adventuresofZackandMax.pdf

****************

Questions for Radio Amateurs

UK licences

International Exam

Sample question

Links

Program notes
Program QADV contains multiple choice questions to help students revise for the Advanced exam that qualifies radio amateurs for a Full UK Licence.
It is also suitable for students of the International exam (HAREC).

All the questions have been specially written for this program, to the same format as used in the exam. They are not questions from past exam papers.

Many local amateur radio clubs run courses for the exam. This program is designed to supplement such courses. It enabled students to consolidated topics they have learnt and to identify any topics that need further study.
And, because it's fun to do, it provides motivation.
Questions can be selected from one or more parts of the syllabus.

Program QADV last updated
16 May 2007

Site last updated
16 May 2007 A new version of QADV uploaded on 17 May 2007

zipqadv.exe is the zipped (compressed) file that contains program QADV.
It is about 2.5MB in size.    Downloading is automatic; and once downloaded, it will unzip automatically.

If you have a previous version of QADV, do not install the new version in the same location before deleting the old one.

Click zipqadv.exe and follow the instruction on the screen.
The process normally goes smoothly; but if it doesn't, see Program notes.

To run 1. Click the Start button
             2. Choose Programs
             3. Click QADV.

Many of the features in this program have been suggested by users. So feedback is always welcome.    Queries?   Corrections?   Comments?    Problems with downloading?
Please email me.

"It [QADV] has proved invaluable for Worthing RC's training programme. Well thought out and very easy to use."
                                 Denzil Roden G3KXF,   Course Tutor,   Worthing Radio Club

http://freespace.virgin.net/murray.g3kzb/

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OHM'S LAW

Basic Ohm's Law

Here we'll attempt to explain Ohm's law basics!

Ohm's law can be very difficult to understand by anyone who has never had any basic understanding or training in basic electricity. We'll assume that you have some knowledge of basic electricity. We'll explain it in terms of water flow! DON'T GET WET!

What is Ohm’s Law:

Ohm's Law is made from 3 mathematical equations that shows the relationship between electric voltage, current and resistance.
What is voltage? An anology would be a huge water tank filled with thousands of gallons of water high on a hill.
The difference between the pressure of water in the tank and the water that comes out of a pipe connected at the bottom leading to a faucet is determined by the size of the pipe and the size of the outlet of the faucet. This difference of pressure between the two can be thought of as potential Voltage.
What is current? An analogy would be the amount of flow determined by the pressure (voltage) of the water thru the pipes leading to a faucet. The term current refers to the quantity, volume or intensity of electrical flow, as opposed to voltage, which refers to the force or "pressure" causing the current flow.
What is resistance? An analogy would be the size of the water pipes and the size of the faucet. The larger the pipe and the faucet (less resistance), the more water that comes out! The smaller the pipe and faucet, (more resistance), the less water that comes out! This can be thought of as resistance to the flow of the water current.
All three of these: voltage, current and resistance directly interact in Ohm's law. Change any two of them and you effect the third.
Info:

Ohm’s Law was named after Bavarian mathematician and physicist Georg Ohm. Ohm’s Law can be stated as mathematical equations, all derived from the same principle. In the following equations,

V is voltage measured in volts (the size of the water tank),

I is current measured in amperes (related to the pressure

(Voltage) of water thru the pipes and faucet) and

R is resistance measured in ohms as related to the size of the pipes and faucet:

V = I x R (Voltage = Current multiplied by Resistance)

R = V / I (Resistance = Voltage divided by Current)

I = V / R (Current = Voltage Divided by Resistance)

Knowing any two of the values of a circuit, one can determine (calculate) the third, using Ohm’s Law.
For example, to find the Voltage in a circuit:
If the circuit has a current of 2 amperes, and a resistance of 1 ohm, (< these are the two "knowns"), then according to Ohms Law and the formulas above, voltage equals current multiplied by resistance:
(V = 2 amperes x 1 ohm = 2 volts).
To find the current in the same circuit above assuming we did not know it but we know the voltage and resistance:
I = 2 volts divided by the resistance 1 ohm = 2 amperes.
In this third example we know the current (2 amperes) and the voltage (2 volts)....what is the resistance?
Substituting the formula:
R = Volts divided by the current (2 volts divided by 2 amperes = 1 ohm
Sometimes it's very helpful to associate these formulas Visually.

The Ohms Law "wheels" and graphics below can be a very useful tool to jog your memory and help you to understand their relationship.

The wheel above is divided into three sections:

Volts V (on top of the dividing line)
Amps (amperes) I (lower left below the dividing line)
Resistance R (lower right below the dividing line)
X represents the (multiply by sign)
Memorize this wheel To use, just cover the unknown quantity you need with your minds eye and what is left is the formula to find the unknown.

Example:

To find the current of a circuit (I), just cover the I or Amps section in your mines eye and what remains is the V volts above the dividing line and the R ohms (resistance) below it. Now substitute the known values. Just divided the known volts by the known resistance.Your answer will be the current in the circuit.
The same procedure is used to find the volts or resistance of a circuit!

Here is another example:

You know the current and the resistance in a circuit but you want to find out the voltage.

Just cover the voltage section with your minds eye... what's left is the I X R sections.

Just multiply the I value times the R value to get your answer!

Practice with the wheel and you'll be surprised at how well it works to help you remember the formulas without trying!

This Ohm' Law Triangle graphic is also helpful to learn the formulas. Just cover the unknown value and follow the graphic as in the yellow wheel examples above.You'll have to insert the X between the I and R in the graphic and imagine the horizontal divide line but the principal is just the same.

In the above Ohm's law wheel you'll notice that is has an added section (P) for Power and the letter E* has been used instead of the letter V for voltage. This wheel is used in the exact same fashion as the other wheels and graphics above.
You will also notice in the blue/green areas there are only two known values with theunknown value in the yellow sections. The red bars separate the four units of interest.
An example of the use of this wheel is:
Let's say that you know the power and the current in a circuit and want to know the voltage.

Find your unknown value in the yellow areas (V or E* in this wheel) and just look outward and pick the values that you do know.

These would be the P and the I. Substitute your values in the formula, (P divided by I) do the math and you have your answer!

Info: Typically, Ohm’s Law is only applied to DC circuits and not AC circuits.
* The letter “E” is sometimes used in representations

of Ohm’s Law for voltage instead of the “V” as in the wheel above.

AHARS - JINGTONG JT-208 / 308 Short Form Users Manual

Common Features:-

• 30 Channels

• 3 operating modes

o Direct frequency entry via keypad

o Memory mode by channel number

o Memory mode by frequency

• Programmable repeater shift

• Programmable repeater offset

• Split frequency operation for Tx / Rx

• Selectable frequency steps of 5/10/12.5/25Khz

• CTCSS operation with 1 of 38 codes on Tx /Rx

• Inbuilt battery saver when muted

• External earphone & microphone operation.

General Specifications :-

• Frequency Range

JT-208 136-174 Mhz

JT-308 400-470 Mhz

• Voltage – 7.2V NiMH rechargeable battery

• Channels – 30

• Antenna Impedance 50 Ohms

• Modes – Simplex, Repeater, Split Tx/Rx

• TX Output Power 1.8 – 2.5 Watts RX sensitivity < 0.16 uV (12dB Sinad)

• Modulation FM =< 5Khz Deviation Mute sensitivity < 0.2 uV

• Spurious emission <-60dB Mute sensitivity < 0.2 uV

• Current on TX =< 600 mA Intermod rejection 50dB

• Negative Ground Audio Power > 300mW

• Dimensions 100 x 50 x 30 mm RX current =< 100 mA – muted 20 mA

Power / Volume control :

Turn clockwise to switch on power, and adjust control for suitable volume level.

Mute Control :

Turn anti-clockwise to un-mute & clockwise to mute receiver.

LED indicator :

When unit is muted the LED is not lit, when receiving a signal the LED will be green and in transmit mode will indicate red.

Setting Frequency Step size : (DF mode)

This function sets the size of the frequency step when using the up / down keys under the LCD display. Before the step size can be set the unit needs to be in the ‘direct frequency’ mode (DF) by pressing [SET] [1] (this should be the default).

To change the step size press [SET] [4] . Continue to press [4] and you will see the step size changing in the following rolling sequence :-

25 125 10 5

Select the step size you require – the default 25 Khz will be adequate for setting most repeater channels. When you have selected the required step size push [EXIT] button.

Setting Repeater Offset : (DF mode)

• The repeater offset function is accessed by pushing [SET] [7]. The frequency of offset is then entered as follows :-

• For 600 Khz (JT-208 VHF) from the keypad enter 0060 – the unit will beep and display the offset as 0 0. 600 - To exit press [EXIT].

• For 6 Mhz (JT-308 UHF) from the keypad enter 0600 – the unit will beep and display the offset as 0 6.000 - To exit press [EXIT].

Turning Repeater Offset on/off : (DF mode)

• This function toggles the repeater offset on or off, as well as setting the direction of the shift positive or negative. To activate push [SET] [6], you will see the LCD display indicate a positive shift by a very small ‘+’ sign to the immediate upper left of the frequency readout. To set to negative offset repeat the sequence [SET] [6] and you will see the sign change to a ‘--‘ sign. To turn the repeater offset off, repeat the sequence [SET] [6] and it will be observed that the symbol has disappeared.

• With the offset turned on the unit will now transmit at a frequency ± the offset entered, the frequency being displayed on the LCD display. This is function is very useful in setting up the memory channels (see section on storing frequencies), but must be turned off for simplex channels.

Setting Frequencies : (DF mode)

In this mode the frequency can be directly entered from the keypad or with a combination of keypad and [+M / –M ] & the [up/down ↑↓ ] keys.

• To enter a frequency (for example 146.525Mhz), the frequency may be entered by keying in 1,4,6,5,2,5 at which time the unit will beep indicating frequency has been entered. the LCD will display 146.525 . The unit will now transmit and receive on that frequency (provided the Offset is switched off).

• The frequency may also be altered to another frequency by using the following keys – [+M] will increment the Mhz display by 1 Mhz for each push of the key, similarly the frequency may also be decremented by pushing [–M] key.

• The Khz section can be altered by using the [UP ↑ ] and [DN ↓ ] keys, and will increment or decrement by the Frequency Step value set previously. If the buttons are held down for more than 3 seconds the display will increment or decrement at the step rate until the button is released.

Storing Frequencies to Memory Channels : (DF mode)

• The unit has 30 memory channels that may be used for storing commonly used frequencies and repeater channels, complete with offset information or with odd transmit and receive frequencies. The procedure is as follows :-

Storing Repeater Frequencies : (offset on)

• Set unit to DF mode with [SET] [1], turn repeater offset on [SET] [6], [SET] [6] to set negative offset mode. Enter the required RX frequency (example 147.000Mhz) by entering 1,4,7,0,0,0 unit will beep, then push [B] key, this will bring up a flashing 2 digit channel number in the right hand side of the LCD. Select your required channel / memory location with the [ ↑ ] and [ ↓ ] keys, then press [C] and the frequency and offset will be stored.

• Repeat this sequence until you have entered all required repeater frequencies then turn off the repeater offset off by [SET] [6] (no ± displayed).

Storing Repeater or odd splits : (offset off)

• Frequencies may also be entered into memory locations without using the Repeater Shift function, which also allows odd frequency splits to be entered as well. An example may be making a memory location for a reverse repeater channel, this is accomplished by the following sequence. Using our above example, entering the reverse channel for Adelaide VK5RAD repeater, the TX / RX frequencies are reversed, the RX will be 146.400Mhz and the TX will be 147.000Mhz.

• Enter from the keypad 1,4,6,4,0,0 then push key [B], the channel number will flash, select desired channel with [ ↑ ] and [ ↓ ] keys, then push [C] key. Then enter 1,4,7,0,0,0 from the keypad and again push the [B] key then push [D] key, which writes the frequency to the transmit register. This is also the method of programming odd TX/RX splits if required.

Using & Recalling Memory Channels : (Memory Mode 1&2)

The JT-208/308 units have two modes for using the memory channels, whilst selecting the required channel for both modes is done by the [ ↑ ] and [ ↓ ] keys, the readout is different. The two modes are set by the following sequences.

• Mode 1 : Channel Display

o This is set by keying in [SET] [2] The display will show CH-01 to CH-30 if all 30 channels are programmed. Note – only the programmed channels will be displayed.

• Mode 2 : Frequency Display

o This is set by keying in [SET] [3] The display will show the frequency programmed into the channel, in our example the LCD will show 147.000 with the channel number displayed as CH-01 in the upper right hand corner of the display, again only the programmed channels will be displayed.

Note that on the channels that have been setup as repeater channels with the offset programmed in the ‘--‘ symbol is displayed as well, where as the simplex and split channels should have no symbol indicated. Note also that direct frequency entry is not possible from channel mode, you must return to DF mode [SET] [1].

Deleting Channels :

To delete all channels and setting press and hold the [SET] key and switch on the unit, the unit will beep and display on the LCD cli - - -

An individual channel may be overwritten by reprogramming a new frequency and storing it as per the above section on storing frequencies.

Scanning :

The units have a scan mode which can scan the whole or part of the frequency range or just the channels. In the DF Mode, a frequency may be entered from the keypad as the start frequency – say 144.000Mhz, then the [A] key is held down for approximately 3 seconds at which time the scanning will start, stepping at the rate set in ‘Step Size’. Scanning will continue until a signal breaks the mute or the [A] key is pressed again, or the PTT is operated.

When in memory mode (1 or 2), the scanning function is limited to the programmed channels and loops from the highest channel back to the lowest channel continuously until mute is broken or [A] key is pushed.

Sub Audible Tones : CTCSS

The units can be setup for CTCSS operation individually or both on TX and RX. Some repeaters use CTCSS tones to help prevent interference from adjacent services from holding the transmitter on, or you may have a favourite channel that you use with someone else and you do not want to hear other traffic on that particular channel. The tones may also be stored into individual channels.

There are 38 standard tones available as shown in the table at the end of this guide and they can be set as follows :

Setting the CTCSS frequency and activating :

• Press [SET] [9] the LCD display shows cr-01

• Use the [ ↑ ] and [ ↓ ] keys to select the required tone from the chart, for example if a sub-tone of 141.3Hz is required, then key up to ‘22’, the display will show cr-22 , then push the [EXIT] key.

• The tone may assigned to the TX function by [SET] [0] to turn it on or off, or to the RX function by [SET] [8] to turn it on or off (toggle).

• The tone will be sent when ever the PTT is pushed for the duration of the transmission, similarly, the mute will only be broken when receiving a signal with correct CTCSS tone.

It is recommended that the CTCSS tones be only put on stored channels, otherwise it will affect the operation of DF mode operation.

Table of CTCSS frequencies (Select in grey – Tone in Hz clear)

1	2	3	4	5	6	7	8
87	71.9	74.4	77	79.7	82.5	85.4	88.5
9	10	11	12	13	14	15	16
91.5	94.8	97.4	100	103.5	107.2	110.9	114.8
17	18	19	20	21	22	23	24
118.8	123	127.3	131.8	136.5	141.3	146.2	151.4
25	26	27	28	29	30	31	32
156.7	162.2	167.9	173.8	179.9	186.2	192.8	203.5
33	34	35	36	37	38
210.7	218.1	225.7	233.6	241.8	250.3

Locking the Keypad :

The keypad may be locked to prevent accidental operation of the keys by [SET] [*]

Jingtong Transceiver Key Functions
Function	Keys	Function	Keys
Lock keypad on/off	*[SET] []**	Start scan mode	[A] or [SET][5]
Direct Frequency Mode	[SET] [1]	Store frequency to memory	[B] select channel [C]
Memory Mode (Channels)	[SET] [2]	Store TX frequency to memory	[B] select channel [D]
Memory Mode (Frequencies)	[SET] [3]
Set step size	[SET] [4]
Repeater shift on/off	[SET] [6]	Unknown ? turns ‘R’ off in LCD	[SET] [#]
Set repeater shift	[SET] [7] enter shift
CTCSS transmit on/off	[SET] [0]
CTCSS mute on/off	[SET] [8]	Clear all memories	Press [SET] while turning on the transceiver
Set CTCSS Frequency	[SET] [9] select code	Clear all memories	Press [SET] while turning on the transceiver

This table courtesy of G4ILO

Adelaide Hills Amateur Radio Society – mailing address P.O. Box 401, Blackwood, South Australia 5051, AUSTRALIA or via e-mail to vk5bar@qsl.net

THE JINGTONGS 208 & 308 HANDIES

OUR GUIDE

User Guide

Understandable English

Jingtong Transceiver Key Functions
Function	Keys	Function	Keys
Lock keypad on/off	*[SET] []**	Start scan mode	[A] or [SET] [5]
Direct frequency mode	[SET] [1]	Store frequency to memory	[B] <select channel> [C]
Memory mode (channels)	[SET] [2]	Store TX frequency to memory	[B] <select channel> [D]
Memory mode (frequencies)	[SET] [3]
Set step size	[SET] [4]
Repeater shift on/off	[SET] [6]
Set repeater shift	[SET] [7] <enter shift>
CTCSS transmit on/off	[SET] [0]
CTCSS squelch on/off	[SET] [8]	Clear all memories	Press [SET] while turning on the transceiver
Set CTCSS frequency	[SET] [9] <select code>	Clear all memories	Press [SET] while turning on the transceiver

JINGTONG Review by G4ILO

The Jingtong JT-208 VHF HT

The Jingtong JT-208 VHF transceiver is a VHF hand-held made in China. (There is also a UHF model, the JT-308.) The principal attraction of these transceivers is that they are very cheap. They can be had for as little as £30 on eBay, and the cost comes down to nearer £20 if you club together with some friends and buy several of them at a time. This was a bargain I found impossible to resist. So what you are probably interested to know is, are they any good, and why are they so cheap?

The reason why they are so cheap isn't hard to guess. China is a vast country with a booming economy, and there is a lot of construction and large-scale manufacturing going on. Workers on construction and factory sites use radios like this to keep in contact. The Jingtong transceivers are not made specifically for the amateur bands, but cover a frequency range that happens to include the 2m band (or the 70cm band in the case of the JT-308.) These radios are probably manufactured in tens if not hundreds of thousands. The low price is due to the economics of producing things in large volumes in China, plus the fact that these radios are not sold by ham radio dealers who exploit the fact that it's a hobby purchase to sell at a huge profit.

I ordered my radio direct from the UK importer, and it arrived the next morning by Royal Mail. In the box was the radio, a short (11cm long) helical "rubber duck" antenna, a drop-in battery charger designed for 220V, 50Hz, a belt clamp and an instruction book. The battery pack was already installed in the radio, and is a 7.2V 60mAH NiCd pack (despite the manual and some ads claiming it is NiMH.) I also purchased one of the optional headsets, which is almost identical to a mobile phone hands-free kit that I have.

The antenna connector is an SMA, but it is an SMA connector with a centre pin, the reverse of all the small amateur band hand-helds I've seen. You may find a BNC adapter hard to obtain. Maplin didn't seem to list one, but I was kindly sent one by Dave, G3VFP, which allowed me to connect the radio to a power meter and an external antenna.

The output power is specified at 1.8W - 2.5W. My radio gave 2.4W output. There is no low power setting.

Receive sensitivity appears to be only slightly less sensitive than my FT-817, but that is more than adequate for the power. The receive audio quality is very good considering the size of the speaker, and there is plenty of it - enough to be heard clearly on a noisy Chinese building site. There is no signal strength meter: the bar graph on the display is absent when the receiver is squelched, and full scale when a signal is present.

On the air

The receiver audio quality may be good, but the transmitted audio is another matter. Using the built-in microphone, it is a bit bassy and muffled (hear a sample). This is a shame, as the radio itself is capable of producing superb audio. I was lucky enough to run across an Internet newsgroup posting mentioning the muffled audio, which also mentioned that the audio was much better using the accessory headset. I ordered one of these with the radio, and the result is a big improvement (hear a sample).

I have seen it mentioned that these Jingtong radios will accept Kenwood headsets (and presumably speaker/mics) but I can't verify this. The connector is a 2.1mm diameter stereo jack. The speaker is connected between the outer ring and the centre connector, and the mic, in series with the PTT, between the outer and the tip. I have wired up a cheap Watson speaker mic and it works fine.

The standard 11cm long rubber duck antenna is, unsurprisingly, not very efficient. So far, I haven't managed to make any contacts using it. I haven't tried any of the accessory antennas sold by the importer. They are cheap enough, however the telescopic whip that is offered is about three inches too short for a quarter wave at 145MHz.

An interesting possible use of this receiver, given its wide band coverage, is as a receiver for APT weather satellites. You couldn't buy a decent receive-only scanner for this price, and the receivers of the cheaper VHF scanners are unlikely to be this good. As with any VHF transceiver, the IF bandwidth is too narrow for optimum reception of APT weather satellites, but I have received usable images using my FT-817 and the filters in the Jingtong JT-208 don't seem to be quite so sharp. I haven't tried feeding the received audio into the computer to see what the results would be like, but I would expect it to be possible to decode it using WXtoImg which is more tolerant of narrow band signals than other APT decoding software.

Conclusion

The Jingtong JT-208 is a real bargain that's hard to resist. It's an inexpensive toy for the individual radio amateur, but it has obvious potential too for emergency communications groups, who could equip the entire group for a small cost. The radio is small, attractively styled and quite ruggedly built. It has all the features you need to operate on the 2m amateur band, and none of the frills you can manage without, which makes it nice and simple to use. The transmit audio could be better, but apart from that, it's hard to think of a reason not to buy one!

Jintong Review by G3VFP

JINGTONG

JT308 UHF FM Or JT208 VHF FM Handi Talky

Not a technical assesment, but more of an overview:

Well here we are witnessing the incursion of cheap transceivers into the hitherto expensive radio amateur market place....Sounds good, well it is not the perfect scenario as yet because these transceivers or handy talkies are really a basic concept when compared to the likes of Alinco, Icom, Kenwood, and Yaesu Vertec.

They have a good sensitivity, and the receiver performs as well as any of the above with a spec sensitivity of less than 0.16uV for 12dB SINAD, the transmitter has 2.5W maximum output at 5Khz deviation reputedly. I say reputably because the one I purchased only exhibited a maximum of 1.5Khz, and had quite a low frequency audio response ( not that I wanted 5Khz anyhow :-) ). In fact I think I can say the transmitted audio was rubbish, and had a permanent hiss in the background.

The unit covers from 400 Mhz to 470Mhz in either 5, 10, 12.5 or 25Khz steps. It has only 15 memory channels which are saved and indicated as CH1 etc rather than by frequency. It has a basic scan facility of these channels, and that works okay. The frequency entry is direct from the keypad, and in normal mode does in fact display the actual frequency. You can program shifts into the tx and rx, so it should be okay for repeater use.

It has upto 38 CTCSS selectable tones, but no DTMF, or tone burst.

The mechanics of the unit are quite sound, the case being quite a sturdy ABS, and the main chassis is aluminium upon which the two pcbs are sat. The display is lcd of course, with a blue led backlight.I think it would sustain quite a few knocks, and certainly does not give the impression of a cheap build. The squelch and volume controls are okay for purpose, but it does have an annoying musical string on switch on.

You will find the user manual amusing, as it is directly converted Chinese to English, not to say you can't follow what it is telling you though :-). Forget about a schematic diagram, or any technical assistance concerning it's design, as the importer told me that the manufacturer has no intention of releasing any schematics, or in depth technical info for that matter. At this moment I am unsure as to whether the deviation level is software controlled, or a fixed gain circuit. For sure there are no user pre set resistors for either mic gain, or deviation level, or anything else, so it would appear there may be a master setup sequence contained within it's cpu.

There are two models in this Chinese manufacturers arsenal, the JT208 covers from 136 to 174 Mhz, and the JT308 as above. The UK importer has spare cases, batteries, pcb's, a remote headphone and mic, and alternative antennas than the tiny helical supplied, and their response to questions by email is quite okay. They are advertised as being proffesional pieces of equipment, but in reality I doubt any of us would consider them as being that. But hey!, the price is low, and for thirty or so pounds for a one off, they are worth playing with, as for that price you get a battery, a rubber duck, and a charger, together with a UK converter plug as well :-). The down side may be that because of their cheap price, and ready availability to anyone on the planet, we may find people using them within our two metre, or seventy centimetre bands who do not possess a radio amateur licence, but then there is nothing new about that is there :-). There seems to be an abscence of either any CE or FCC marking, so I think we can take it, that it has not been presented for approval yet.

If you have any other information to impart for me to include, then please email me. Below there are a couple of pictures. The first showing the unit with a hole cut through to improve the output from the electret mic. The second is a wiring diagram of the 2.5mm stereo jack so you can use a seperate headphone, and electret insert...or a modified Nokia type hands free unit.

Regards,

Dave G3VFP

These components can be obtained from

Modern Radio (Bolton)

Tele: 01204 526916

General Radio Support Issues

Jingtong Transceivers

If you are having a problem with either of our Transceivers this is the place to be!

Here is a few basic instructions on how to use the features of the transceiver:

To lock the Keys press "Set" then *, to unlock do the same.
To Scan through all the frequencies press the "A" Button.

To Store a Channel:

Press 'B'
Select Channel using the up and down arrow keys (on the right above the main keypad)
Type in frequency required using the number keypad (i.e. 144.570)
Press 'C' to store

To retrieve or scan Stored Channels

Press 'Set' then '2' to enter channel mode
Use arrow keys to browse stored channels.
Press 'A' to scan stored channels.
To return to Frequency mode press 'Set' then '1'

If you just want to listen to a particular frequency all you do is type it in.

To Enter CTCSS Mode Press "Set" then "0", press the same keys again to return to normal mode.

To set CTCSS Code Press "Set" then "9" and use the arrow keys to select the number required.

To Change the Frequency step (5/10/125/25KHz) Press "Set" then 4, keep pressing 4 until the desired step is shown on screen then press "Exit".

To Transmit and receive on different frequencies you must first subtract the lower frequency number from the higher frequency number to give you the amount in MHz difference between the 2.

For Example. Transmit on 452.000, Receive on 458.000.
458.000 - 452.000 = 6.000 so there is a 6.000 MHz difference between them. To Set the difference press "Set" then "7" and enter the difference then press "Set" again. To check it has entered press "Set" then "7" again and it will show the difference.
To set the radio to use this code press "set" then "6", a small plus will show at the top of the display. The example I have given above shows that the transmission frequency is set lower than the receive frequency so we need to press "Set" then "7" again so a minus sign shows. The unit is now set up all you have to do is enter the receive frequency (458.000) and when you transmit you will see the screen change to the transmission frequency (452.000). To turn the Feature off press "Set" Then "7", repeat until no plus/minus sign shows.

F.A.Q's

Q. Why is there is no sound coming from my transceiver?
A. Please check the squelch is correctly set and the volume is up. If these are correct it may have entered "CTCSS" Mode, Press "Set" then "0" to return to normal mode.

Q. Why does the he charger have a 2 pin plug?
A. We buy these in massive bulk from Asia to offer the best price (Asia - 2 pin plug). We supply an adaptor for use in the UK. If using in Europe you may need to purchase an adaptor. Alternatively it is very easy to fit a 13 amp plug.

Q. What if I need to buy a spare battery?
A. No problem UK2Way stock replacement batteries as well as a range of spare parts and accessories.

Q. What if I have a problem with it in the first year?
A. We offer a years warranty against manufacturing faults so you can send it back for repair/replacement. However if the item is damaged due to misuse then this is not covered by our warranty.

Q. Do I need a license to use these?
A. It is best to check with your local authority whether a license is required. The units do cover a lot of frequencies including amateur Radio bands. You do need a license to use these units on the amateur radio frequencies.

Q. Can I use this unit to listen to frequencies like a Scanner?
A. Yes you can! However these units can receive certain emergency services such as the Police, Please bear in mind that it is ILLEGAL to listen to such frequencies.

AMATEUR CONVERSION INFORMATION

Key Radio KM Series
Amateur Conversion Information

by Tom Grady G6IGA keyradio@superiorsignals.co.uk copyright 1998-2005

All registered trademarks are acknowledged

Key KM150 (KG105) Radio

The Key (Kyodo) Radio is an extremely versatile PMR or trunked radio set, which can be converted and utilised for many amateur radio bands (70cm,2m,4m).

Identifying the Key set you have

Located on the back left of the set near the speaker socket, is a small sticker located on the PA heatsink. This helps identify the type of radio and its suitability for use, of course it should have a serial number plate on the right hand side, saying what it is, but this is not always the case.
Key Stickers on PA

Yellow centre then white with outer blue ring KM450 (KG105) UHF 430-470MHz - suitable for 70cms use.

White only KM225 BAND3 177-207MHz trunking radio - important characteristic - no squelch pot. Not used directly for amateur conversion, but the 40 channel head, chassis, PLL Board, Mic and interface board can be transplanted onto one of the other types of set. Important the RF Board, PA, VCO and trunking signalling board cannot be used for amateur conversion.

Blue centre then white with outer purple ring KM150 (KG105) HIGH BAND 136-174MHz - suitable for 2metre use.

No sticker but 'short' half the normal length PA - KM80 LOW BAND 70-87.5