AOR AR-900 Scanner

Handheld Amateur VHF/UHF Scanner / receiver

Specifications

Frequency range RX

• 27-54 / 108-174 / 406-512 / 830-950 MHz (USA)

Tuning steps

• 5 / 10 / 12.5 / 25 kHz

Modulations

• AM / FM

Sensitivity

• AM: 1 µV (10 dB S/N @ 118-136 & 220-380 MHz)
• FM: 0.5 µV (12 dB SINAD @ VHF)

Receiver system

• Double conversion

IF-frequencies

• 1st: 21.4/177 MHz
• 2nd: 455 kHz

Image rejection

• 30 dB @ 120 MHz
• 11 dB @ 935 MHz

Other

• Power requirements 4.8~6V DC (4×AA/R6)
• Memory of 100 channels in banks A - E

Quick Start

For those, and that is the vast majority of us, who want to listen to something immediately and read the Instruction Manual later, please carry out the following steps:-

1.Fit the thinner of the two aerials (push on and turn).

2.Turn squelch (SQ) control fully counterclockwise.

3. Turn volume (VOL) control clockwise to a comfortable listening level.

4. Turn squelch clockwise until the background noise stops.

5.Press the following keypad buttons in order

Search Progm. If the letters FM show in the middle right hand edge of the display, move to the next step, but if AM j shows press AMFM until FM shows.

Next step - press 9,3,6,ENT,PRY LUUL, 9, 4, 0, ENT, and then press LOCKOUT/INC until 12.5 shows at the top of the display slightly right of centre, ENT, SEARCH (NOT search progm). TheAR9ooUK should, if the battery is not flat, start searchingpart of the Cellular telephone band and you should hear signals. If the search stops on a signal which is unintelligible, pressing SEARCH (not search progm) will restart the search. If the AR9ooUK does not seem to be working properly, the battery may be flat - charging instructions follow a bit firrth er on, but be absolutely sure you have carried out the above instructions to the letter before giving up in despair.

INTRODUCTION.

The AR-900UK is manufactured by A.O.R. Limited" of Japan whose products, going back a long time, have gained a world-wide reputation for both performance and reliability second to none. It has been carefully engineered and manufactured to a rigid specification capable of giving satisfactory and dependable Operation for many years.

After unpacking, it is as well to keep the packing material in case it should ever be needed for remote operation, maintenance or service, and check that it is supplied with the following accessories:

1 - AC Adaptor/Charger. Input 24oVAC 5oHz 5W. Output 6VDC ZOOmA.

It will be necessary to attach a mains plug to this unit suitable for fitting into a standard domestic power socket.

2 - Flexible helical whip aerials, one slightly thicker than the other.

1 - Instruction Manual.

Before using the charger for the first time we recommend that the battery be fully discharged by switching on the dial light. When this goes out or the “bat low” warning appears on the display, switch it off, plug one end of the charger into the mains, the other end into the AR9ooUK charger socket marked “CHG DC6V”, and charge for 8-10 hours. The reason for this procedure is that

Nickel Cadmium (NiCad) batteries may acquire what has been described as a “memory” which subsequently gives rise to difficulty in charging them fully. This full discharge/charge cycle at the outset minimises this problem and ensures that optimum battery usage is achieved. Note that during the initial discharge you can use the ARQOOUIC but it will, in all probability soon start to die on you as the battery gets flatter and flatter. The same thing applies to the initial charge - it will take several minutes to start coming to life again, but after that there is no reason why you should not use it, but I would be inclined to leave the dial light 017'. One other thing to remember - if you use the AR9ooUK during the charging cycle, then the charging time should be increased to compensate. As overcharging: is not unduly harmful it is not necessary to set the alarm for 3 am. to switch the charger off - up to 16 hours once in a while will not hurt. Repeating this rapid discharge/full charge cycle three or four times is not a bad idea and results in the NiCads reaching their full capacity of 7 to 9 hours normal usage. Subsequently, an overnight charge or a charge while you are at work when the low battery (Bat-Low) warning appears on the display is all that is necessary. As for the total life of the NiCads - hard to say o depends not only on usage but many other factors, but I would be a bit disappointed if they only lasted a year and delighted if they lasted four. Fortunately they do not cost the earth to replace.

Operating modes

The AR9ooUK can be used in three different ways. In the MANUAL mode, any frequency within the tuning range may be entered into any of the 100 memory channels (Ao1 to E20) and,recalled by entering the appropriate channel number. Additionally, repeated pressing of MANUAL goes through the memories sequentially, tuning to the different frequencies in them. The second mode of operation is the SCAN facility whereby up to 100 frequencies are manually put in the memories and then rapidly scanned. Should there be a signal present, the AR9ooUK will stop scanning to permit the signal to be heard. The 100 memories are in 5 (A,B,C,D,and E) banks of 20 and any bank or combination of banks may be scanned. One popular method of use is to have local airfield and airways frequencies in one bank, Radio Amateurs in another, Private Mobile Radio in a third, cellular car' phones in a fourth and so on, scanning the bank. or banks of current interest. Should interest in one or more frequencies temporarily wane, that frequency or frequencies may be temporarily locked out by pressing the LOCKOUT/INC key. Pressing a second time brings the frequency back. into the scan. The SCAN operation presupposes that the user knows firstly what frequencies to put in the memories and secondly whether the transmission is AM or FM. There are several books which list various frequencies and your Dealer will be happy to advise. As to whether a transmission is AM or FM, a good general rule is that all airband, civil and military are AM, anything else is FM, but if in doubt, trying both will determine which is correct. For the beginner who has little or no idea of what frequencies are in general use in his area, the third mode of operation comes into its own. This is the search mode, and in this mode the AR9ooUK will scan between two programmable limits, stopping wherever there is a signal.An example of this mode of operation was given at the start of this manual. A good starting point is to consult the “Band Plan” listed further on and decide what you would like to listen to. Take a small portion of the band and search that portion noting any interesting frequencies or putting them directly into a memory bank by use of the HOLD facility described later. Having exhausted the possibilities of that particular portion, repeat over the next portion, and so on, not attempting to search more than a'1MHz portion at a time, otherwise there is a strong possibility that some transmissions will be missed. After 20 frequencies have been entered into a memory bank, it will, of course, be necessary to start a fresh bank.