Radio Frequencies of Interest
to Telephone Experimenters
by THE RESEARCHER
(Updated 03/01/87)
Be advised that since I originally wrote this article, a new Electronic
Communications Privacy Act (ECPA) has been passed by that mistress of Big
Money, the U.S. Congress. It is now illegal to monitor cellular or conventional
mobile telephone calls.
A lot of technically oriented telephone experimenters are finding out
about an exiting world of telephone activity in the radio spectrum. Most of you
are probably acquainted with mobile telephone channels in the VHF band and know
that these conversations can be monitored. Frequencies have been allocated in
the VHF and UHF bands for use by land mobile, marine and air-ground stations.
Another fascinating group of frequencies are the high seas channels in the high
frequency short wave band. I have spent many hours listening to ship to shore
telephone calls from ocean liners on the Atlantic.
Scanner radios are used to monitor the VHF/UHF channels. To listen to the
high seas channels you will need a short wave receiver capable of copying
single sideband transmissions. Nearly all high seas calls are transmitted on
upper sideband.
The new cellular telephone channels lie between 825-845 MHz and 870-890
MHz. There are 666 of these spaced 30 kHz apart. I am aware of three
manufacturers who make scanners capable of receiving these frequencies.
They are ICOM America (IC-R7000), Yaesu Electronics Corp. (FRG-9600) and Ace
Communications (AR-2002). Ads for all these can be found in "Popular
Communications". These are professional quality communications receivers and
are expensive. There are converters available from Hamtronics, inc. and others
which permit most scanners to tune these frequencies. Hamtronics' address
is 65-B Moul Road, Hilton, NY 14468-9535. Phone: 716-392-9430. The cost is
$88.00 plus $3.00 shipping and handling.
Mobile Telephone Frequencies
VHF Low Band (Freq. in MHz)
Channel Base Mobile
------- ---- ------
ZO 35.26 43.26
ZF 35.30 43.30
ZH 35.34 43.34
ZM 35.38 43.38
ZA 35.42 43.42
ZY 35.46 43.46
ZR 35.50 43.50
ZB 35.54 43.54
ZW 35.62 43.62
ZL 35.66 43.66
---------------------------
VHF High Band
1 454.95 459.95
2 454.9 459.9
3 454.85 459.85
4 454.8 459.8
5 454.75 459.75
6 454.7 459.7
7 454.725 459.725
8 454.775 459.775
9 454.825 459.825
10 454.875 459.875
11 454.925 459.925
12 454.975 459.975
Signaling 454.675
---------------------------
The following is a list of the channels used for high seas phone calls.
As a rule, the 4 MHz band comes in best at night while the higher channels are
best received during daylight hours. All frequencies are in kilohertz.
(Editorial Note From Scan_Man: These frequencies have been monitored by phreaks
for the purpose of getting calling card numbers. Since the person making the
call must pay for it, its either cash (not in most cases) or most likely a
calling card. In the case of the calling card, the ship operator must read
the calling card number over the air to the coastal operator. Im surprised
more people havnt thought of this)!
