Electra Bearcat 101

The Bearcat 101 is a unique "synthesized" automatic scanning monitor receiver for home, office or mobile use. Through the use of advanced computer technology, Electra has designed exclusive frequency synthesis integrated circuits which provide "crystal controlled" operation of over 15,000 frequencies without the expense of crystals. Changing frequencies is achieved simply from the front panel as explained in the Programming Section.

The Bearcat 101 will monitor any 16 frequencies desired in any order and band combinations. Each individual channel may be changed by "programming" it with a new frequency code. By combining the advantages of "track tuning" (full band coverage) and "frequency synthesis," the Bearcat 101 receives thousands more frequencies than any other scanning monitor available.

You can find out more about professional and hobby scanning in the following books: (click on the title for additional information)

• Specifications
• Operating Instructions
• Programming the BC-101
• The EASY Approach to Programming!

• Common Use Frequencies
• NOAA Weather Channels

• Out of Band Frequency Programming

• Corrections

GENERAL DESCRIPTION
The Bearcat 101 will monitor any 16 frequencies desired in any order and band combinations. Each individual channel may be changed by "programming" it with a new frequency code. Through the use of advanced computer technology, Electra has designed exclusive frequency synthesis integrated circuits which provide "crystal controlled" operation of over 15,000 frequencies without the expense of crystals. Changing frequencies is achieved simply from the front panel as explained in the Programming Section. By combining the advantages of "track tuning" (full band coverage) and "frequency synthesis," the Bearcat 101 receives thousands more frequencies than any other scanning monitor available.

• 16 Reprogrammable Channels.
• Unique circuits permit instant selection from more than 6,000 frequencies.
• No channel crystals required.
• "Remembers" frequencies without batteries even when unplugged.
• Exclusive "auxiliary memory" can be programmed for selective scan delay or external control of accessories on desired channels.
• Exclusive five band coverage:
  1. Low Band 30-50MHz, total spread 20MHz
  2. 2-Meter HAM 146-148MHz, total spread 2MHz
  3. VHF High-band 148-174MHz, total spread 26MHz
  4. UHF-band 450-470MHz, total spread 20MHz
  5. UHF "T" band 470-512MHz (TV Band), total spread 42MHz
  Plus: UHF-band 416-450MHz (Goverment Band), total spread 34MHz
  
  
  Actual receive frequency range is believed to be:
  Low band: 10.745 to 51.701 MHz
  Hi band: 143.745 to 184.701 MHz
  U & T band: 409.6625 to 512.001 MHz
  NOTE: Sensitivity quickly drops off outside the published frequency limits.
  
  
  Sensitivity: H and L bands: readable at .25 microvolt for +/- 5KHz deviation, .6 microvolt for 20db signal-to-noise ratio: U/T band slightly less.
  
  Audio Output: 3W RMS
  
  Scan Rate: Approximately 20 channels per second.
  
  Frequency Selection: New frequencies are entered simply from the front panel. No plug-in crystals required.
  
  Frequency Retention or "Memory": Without batteries or other power.
  
  Bearcat 101 Coverage:

            Band     Frequency Spacing     No. of Frequencies
            30-50             10kc               2,000  
           146-148             5kc                 400
           148-174             5kc               5,000
           416-450          12.5kc               2,720  
           450-470          12.5kc               1,600
           470-512          12.5kc               3,360
                                                 -----
                                                15,080
  

SELECTIVE RESCAN DELAY FEATURE
Some communications systems ("simplex") use a common frequency for both base station and mobiles. On these channels, it is desirable for a scanning monitor to pause for about one second after a transmission for a possible reply before resuming scanning. Other systems (duplex) use separate frequencies for base and mobiles. Rescan delay is undesirable on these channels as the delay is unnecessary and may result in missed communications.

BC-101 provides selective rescan delay which can be used only on those channels where it is desirable. Rescan delay is selected at the time a channel is programmed by placing the #16 programming switch in the UP position (step #7 of programming instructions).

ACCESSORY CONTROL FEATURE
Available from Electra dealers is an adapter which allows the BC-101 to control an external device such as an alarm, external speaker or tape recorder. The adapter, ACA-402, connects to TB1 on the back panel of the receiver and is programmed just as rescan delay is programmed. Then, when the receiver stops on a channel which has been programmed for accessory control, the accessory will operate. The ACA-402 provides single-pole, double-throw contacts which can switch up to .5 Amps and 40V. To avoid personal injury, DO NOT CONNECT HAZARDOUS VOLTAGES (Greater than 40V) to the ACA-402.

Accessory control and rescan delay cannot be used together. Connecting the ACA-402 automatically disables rescan delay.

This receiver is shipped complete with telescoping antenna and programming instructions allowing full-band, all-band coverage of signals in fair-to-good signal-strength areas.

1. With the power cable and antenna properly connected, turn the receiver ON by rotating the "VOLUME" control clockwise.
2. Place the 16-channel switches in the up (ON) position.
3. Set the "MANUAL-SCAN" switch on "MANUAL."
4. Adjust the "SQUELCH" control clockwise until a rushing noise is heard. Then adjust the "SQUELCH" control counterclockwise until the rushing noise disappears.
5. Press the "MANUAL-SCAN" switch downward and continue to step through all channels. If the noise should reappear or "break the squelch" on any channel, adjust the squelch control counterclockwise again slightly, to quiet the receiver. THIS MUST BE DONE BETWEEN STATION TRANSMISSIONS.
6. If your receiver has been programmed to receive your local frequencies, it is now ready for operation. If not, follow instructions in the Programming Section.
7. The "MANUAL-SCAN" switch may now be used to select and monitor any desired channel.
8. To sample all channels automatically, return the "MANUAL-SCAN" switch to "SCAN." Any channel may be omitted as desired by moving the individual channel switch downward (OFF).

By simple front panel programming, any frequencies in the bands shown can be selected from the code table and put into the 16 channels in any desired order. Having determined the frequencies you wish to receive, follow the programming instructions listed below.

In step #1 when the "ready" switch is pushed down, the 16 channel switches are changed from their normal lock-out function to become "data entry" switches. When the "enter" switch is actuated, an automatic cycle begins which erases any previous data in the memory for that channel and "enters" the new data (or frequency) then set up by the 16 switches.

PROGRAMMING INSTRUCTIONS
To program a channel frequency:

1. Move "READY" switch to "DOWN" position (Program indicator will light).
   
2. Move all of the 16 lever switches to the down position.
   
3. Manually step channel indicator to channel number to be programmed.
   
4. Determine exact frequency you wish to receive on that channel.
   
5. Find the frequency in the "look-up" chart. If the desired frequency is not in the chart, refer to Programming by Formula.
   
6. The number alongside the frequency in the look-up chart indicate which lever switches should be moved to the "UP" position. Move indicated switches to the "UP" position. Recheck the numbers and switch positions to be sure they are correct.
   
7. If you desire "rescan delay" on this channel, move lever switch #16 to the "UP" position.
   
8. Move the momentary contact (spring return) "ENTER" switch to the "DOWN" position and release. Channel indicator will turn off for about one second. This channel is now programmed.
   
9. Repeat steps 2 thru 8 for each frequency to be programmed.
   
10. When programming is complete, return the "READY" switch to the "UP" position ("program" indicator light will go off). The 16 switches now function as channel lock-out switches again.

How to calculate switch positions from frequencies not listed in the look-up Table - select from the following frequency ranges:

PROGRAMMIMG BY FORMULA
• VHF LOW-BAND Frequencies (30 - 50 MHz)
• VHF HIGH-BAND Frequencies (146 - 174 MHz)
• UHF-BAND Frequencies (416 - 512 MHz)
• See a Programming Example

Low-Band: (30-50MHz)
To determine the switch settings for a LOW-BAND frequency:

A. Multiply the frequency by 200 and round off to the nearest whole number.
B. Subtract the number obtained in step A from 10340. Call the result "M."
C. Next we must mark the numbers shown below which will add up to exactly M. This is easily done by the following step-by-step procedure:


1. Place an "X" in the square corresponding to the largest number which is less than or equal to M.



4096	2048	1024	512	256	128	64	32	16	8	4	2	1	U	V	D
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16


2. Subtract the number corresponding to this column from M.
3. Repeat steps 1 and 2 until M = 0.
4. To check the program, add all of the numbers marked by an X. The sum should equal M.


D. Place an X in columns 14 & 15.
E. If rescan delay is desired on this channel, place an X in column 16.
F. The Columns with X's denote channel switches to be placed in the UP position. The columns without an X denote channel switches to be placed in the DOWN position.

See example below

High-Band: (146-174MHz)
To determine the switch settings for a HIGH-BAND frequency:

A. Multiply the frequency by 200 and round off to the nearest whole number.
B. Subtract the number obtained in step A from 36940. Call the result "M."
C. Next we must mark the numbers shown below which will add up to exactly M. This is easily done by the following step-by-step procedure:


1. Place an "X" in the square corresponding to the largest number which is less than or equal to M.



4096	2048	1024	512	256	128	64	32	16	8	4	2	1	U	V	D
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16


2. Subtract the number corresponding to this column from M.
3. Repeat steps 1 and 2 until M = 0.
4. To check the program, add all of the numbers marked by an X. The sum should equal M.


D. Place an X in column 15.
E. If rescan delay is desired on this channel, place an X in column 16.
F. The Columns with X's denote channel switches to be placed in the UP position. The columns without an X denote channel switches to be placed in the DOWN position.

See example below

U & T Bands: (416-512MHz)
To determine the switch settings for U and T BAND frequencies:

A. Multiply the frequency by 80 and round off to the nearest whole number.
B. Subtract the number obtain in step A from 40964. Call the result "M."
C. Next we must mark the numbers shown below which will add up to exactly M. This is easily done by the following step-by-step procedure:


1. Place an "X" in the square corresponding to the largest number which is less than or equal to M.



4096	2048	1024	512	256	128	64	32	16	8	4	2	1	U	V	D
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16


2. Subtract the number corresponding to this column from M.
3. Repeat steps 1 and 2 until M = 0.
4. To check the program, add all of the numbers marked by an X. The sum should equal M.


D. Place an X in column 14.
E. If rescan delay is desired on this channel, place an X in column 16.
F. The Columns with X's denote channel switches to be placed in the UP position. The columns without an X denote channel switches to be placed in the DOWN position.

See example below

To program a LOW BAND frequency of 40.000MHz:

A. 40 x 200 = 8000
B. 10340 - 8000 = 2340 = M


4096
2048
1024
512
256
128
64
32
16
8
4
2
1
U
V
D
 
X
 
 
X
 
 
X
 
 
X
 
 
X
X
X
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16


                                     Check
C.      M = 2340                      2048
           -2048  =   Sw 2             256
           -----                        32
             292                     +   4
           - 256  =   Sw 5           -----
           -----                      2340 = M
              36
             -32  =   Sw 8
           -----
               4
             - 4  =   Sw 11
           -----
               0

D. X in columns 14 and 15.
E. Rescan delay is desired for this channel so an X is placed in
   column 16.
F. To program this channel for 40.000MHz, switches 2, 5, 
   8, 11, 14, 15 and 16 must be UP on the radio while 
   programming.

Freq     Service          Switch Configuration
MHz      Name             01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
162.550  NOAA Weather 1   UP DN DN DN UP DN UP DN DN UP UP UP DN DN UP DN 
162.400  NOAA Weather 2   UP DN DN DN UP DN UP UP DN UP UP DN DN DN UP DN
162.475  NOAA Weather 3   UP DN DN DN UP DN UP DN UP UP UP DN UP DN UP DN
162.425  NOAA Weather 4   UP DN DN DN UP DN UP UP DN DN UP UP UP DN UP DN
162.450  NOAA Weather 5   UP DN DN DN UP DN UP UP DN DN DN UP DN DN UP DN
162.500  NOAA Weather 6   UP DN DN DN UP DN UP DN UP UP DN DN DN DN UP DN
162.525  NOAA Weather 7   UP DN DN DN UP DN UP DN UP DN DN UP UP DN UP DN

Bill Petrowsky, has written a program that generates the frequency codes necessary to program the following vintage scanners: Electra's Bearcat 101, Radio Shack's Realistic COMP-100, Regency ACT-W10 (Whamo 10), Sears 5 Band Cardomatic, Tennelec MS-1 (and MS-2), and SBE Optiscan. The Optiscan portion of the program is courtesy of Gary Jacek. Instructions and a screen capture program (to save your results) are included in the SCANPROG zip file available on Bill's webpage.

There is also BCProg written by Ken Harris "Crossfire905" that will generate the switch positions.... it even features a reverse lookup that turns switch sequences back into frequencies. The user interface is graphical; it is a DOS-native application and can be download here... BCProg

Please note that this document is provided for information purposes only: there is no warranty expressed or implied.

All items listed here may be subject to change at any time. Thus, some items MAY be inaccurate.