JingTong

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Jingtong is a Hong Kong based radio manufacturer. They have two main lines, the JT-208 and JT-308.


The User's Manual has some of the best examples of engrish ever made, so I'm going to have to re-write the manual here. (Look at http://www.freewebs.com/jingtong/usersmanual.htm to see the original)

Contents

Review

I got a Jingtong JT-308 transiver today in the mail. The first thing I noticed was that it was small. It easily fit in the palm of my hand, of course I have big hands.

The package I got contained a radio, antenna, 110V charger, belt clip, and wrist strap. Assembeling it was obvious, which was good 'cause they didn't actually give instructions for that. The wrist strap is hard to get on, but that's so common I almost didn't mention it. The belt clip is a peice of metal coated in black paint, not a peice of plastic. The radio included a detachable battery pack (which I'm told is filled with AAA's).

The antenna jack is a male SMA connector and really isn't very usefull if you want to put a diffrent antenna on it.

Next to the antenna, it has a squelch knob, a power/volume knob, and one LED which is red for TX and green for RX. The volume knob is very tight. Following the advice of a random web page, I used plyers to raise it a fraction of an inch to make it turn more easily.

This radio is a bit cryptic to use by modern standards. It has no menus, so you really have to read the manual. Most (all???) options are set by pressing the SET button and an other key, like 1, for example. None of the buttons are labeled with their options.

Once you get past the language barrier and know what you're doing, the radio is easy to program and use. Having a full numeric keypad to enter frequencies is nice, especially if your other radio has a full numeric keypad for DTMF but won't let you enter frequencies directly (*gives the HTX-252 the evil eye). When the backlight is on, the display is very easy to read, and it seems to have good signal.

The radio claims it's frequency rage is 400 MHz to 470MHz. I can punch in as high as 469.975, but I might get closer to 470 if I change the stepping. The radio claims to transmit at both of those frequencies (Well, the tx/rx light goes red, and if the repeater offset is 5MHz, it refuses to transmit outside of the 400-470MHz range). My understanding is that we are only licensed for 420MHz to 450MHz, so this radio allows out of band transmisions between 400 and 420MHz, and between 450 and 470MHz. I want to hook some test equipment to confirm this, but care should be taken to not transmit in these ranges! If you program one of these into memory, I suggest programming the transmit frequency to a frequency inside the ham band, such as 147.57MHz or another simplex frequency, so that if you accidentally transmit you will not be out of band.

The JT-208 is capable of transmitting and recieving on the marine VHF band, and the NOAA Weather Radio Frequencies.

While within the JT-308's frequency range, the Family radio's frequencies may be hard to recieve due to stepping problems. For example FRS channel 1 is 462.5625 MHz, while the JT-308 can be tuned to 462.560 or 462.565, being .0025MHz off. I have not been able to experiemnt with this because I do not have any family radio equipment.

The documentation says that it can store 15 channels, but it allows me to select slots numbered 1 to 30.

The charger says the output is DC7.2V, 100mA. I put the multimeter up to the charger, and on DC it say 12.30V, on AC it said 26V, and the oscilloscope said it was going 0 to 18V 60Hz (I wonder if it could be easily charged off 12VDC).

Overall, 7/10. It's a simple, basic radio, at simple basic radio prices.


  • * * July, 21 Update * *

I got my 2-Meter version (JT-208) today. It works exactly like the other one. This version has a frequency range of 136MHz to 174MHz. This one came with a 220V charger (it was listed that way in the auction, so it's not "Get a random battery charger"). I opened it up and decided to create a 12V Jing Tong Battery Pack Charger.

Pros

  • $20 +s/h, total of $45US
  • comes with rechargeable batteries and charger
  • 2.5 Watts

Cons

  • Illegable manual
  • shipped from the far east, shipping takes a fortnight
  • No DTMF
  • CTCSS codes are table based, so you have to referance the manual.
  • Not faceplate comes off easily.
  • The earphone jack isn't 1/4 inch.
  • 2.5 Watts
  • Allows out of band transmitting.
  • can't disable the power up beep sequence. (seven assending tones at full volume)
  • Not FCC approved (of marginal importance to the ham community)

User's Manual

This is my re-write of the manual, so it'll make sense to me later.

General Use

Power

Turn the PWR/VOL knob clockwise to power on the device. You should hear a series of tones to indicate that it has been activated.

Repeater Offset

  • To select positive or negative offset, Press SET-6. This will cycle through +, -, and no offset.
  • To set the frequency diffrence, press SET-7, then input the diffrence. For example, 5MHz offset would be 0 5 0. When you have finished entering the number, press SET again to save and return from this submenu.

Modes

This radio has two modes: VFO mode and memory mode (VFO mode is called Whole frequency working mode in the manual). In VFO mode, you can directly enter a frequency, while in memory mode, you can select frequencies that have previously been stored in memory. This radio has 30 channels to store frequencies in.

  • To select VFO mode: Press SET 1
  • To select Memory mode: Press SET 2
  • To select Memory mode, but also display the frequency, Press SET 3

CTCSS

The JT radios have three modes of CTCSS (Called VF in the manual): Send and receive, Send Only, and disabled.

In Send and receive mode, the radio will send the selected tone when you transmit and will supress any signal you recieve that does not have that tone. To select this mode, press SET 8 until CODE CT is indicated in the upper left hand corner of the display.

In Send only off, the radio will send the selected tone when you transmit, but will not supress a incoming signal. To set this mode, press SET 0 until CODE CT is indicated and a image of a bell is indicated in the upper right hand corner of the display.

To disable CTCSS, press either SET 0 or SET 8 until the display does not have CODE CT in the upper left hand corner.

To select which CTCSS tone to use, Press SET 9, then use the ^ and v keys to select the code that coresponds to the CTCSS frequency you need. Refer to the CTCSS Codes table here or in your manual.

Memory

To store a frequency:

  1. Set the RX frequancy, including setting any CTCSS tones
  2. Press B
  3. Press ^ and v to select the channel number to store it at.
  4. Press C to store the RX frequancy

To set a specific TX Frequency, other then the normal offset:

  1. Enter the TX frequancy
  2. Press B
  3. Press ^ and v to select the channel number to store it at.
  4. Press D to store the TX frequancy

To change the CTCSS mode or tone for a single channel, go to memory mode, select the channel you want to change, and change the value.

To delete a frequency: No way is known to delete a single channel at this time.


To clear all of the memory:

  1. Turn off the radio.
  2. Press and hold SET
  3. Turn on the radio
  4. wait for the power-on tones to finish
  5. release SET

To use stored frequencies, switch to memory mode.

Tables

Summery of Set Commands

Most of the time, simply typing the frequancy will tune to it.

Most settings are set by pressing SET followed by a number. Here is the table of options:

Set Function
1 Switch to VFO Mode
2 Switch to Memory Mode
3 Switch to Memory Mode, but still display the frequency.
4 Set stepping
5 Scan
6 Set repeater offset direction
7 Set repeater offset's frequency diffrence
8 Toggle CTCSS(pl) tone for sending and receiving
9 Set CTCSS tone
0 Toggle CTCSS tone for sending only.
* Lock/Unlock the keypad
A Scan

CTCSS Codes

1 2 3 4 5 6 7 8
67 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

See Also

Pictures

Projects and Hacks

External Links

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