Post Number: 6384
|Posted on Wednesday, July 20, 2005 - 12:21 am: ||
The COBRA 150 GTL DX
AM/FM 10 METER MOBILE AMATEUR TRANSCIEVER
Complete Specifications, Modifications, and Non - Technical Review.
Lon ~ Tech808 ~ N9OSN ~ CEF808
|Emission Modes||AM/FM |
|Antenna Impedance||50 ohms |
|Antenna Connector||Standard SO-239 type |
|Microphone||Cobra M73SL (Plug-in dynamic with Press-To-Talk switch and coiled cord |
|Frequency Range Stock||28.0 to 29.7 MHz |
|Frequency Range (after conversion)||26.065 to 29.695 |
|Frequency Control||Phase-Lock Loop (PLL) Synthesizer |
|Frequency Stability||0.005% |
|Operating Temperature Range||-22 F to 122 F (-6 C to +50 C) |
|Input Voltage||13.8 V DC nominal / 15.9V max Positive or Negative Ground |
|Currant Drain||Transmit: 3.0A / Receive (squelched) 0.5A / Receive (maximum audio output) 1/2A |
|Dimensions / Size||2-3/8 (H) x 7-7/8 (W) x 9-3/4 (D) |
|Meter||(3 in 1)Illuminated-indicates relative output power / received signal strength and SWR |
|Built in Speaker||4 watts|
|Power Output||Low ~ 4 watts / High ~ 15 Watts |
|Final Transistors||Mitsubishi RD16HHF1 Silicon Mos Fet (x2) Rated at 16 watts at 30 MHz |
|Frequency Tolerance||500Hz |
|Frequency Response||300 to 3000 Hz |
|Transmit Distortion||2% |
|Spurious Harmonic Emission||-65dB |
|Output Indicators||Meter shows relative RF output power and SWR. Transmit LED glows red when transmitter is in operation |
|Antenna Warning LED||Glows red when SWR is greater than 3.0|
|Sensitivity||AM:0.5 µV for 10dB S/N, FM:025 µV for 12 dB S/N |
|Audio Frequency Response||300 to 3000 Hz |
|Maximum Signal to Noise Ratio||45dB |
|Image Rejection||75 dB |
|Adjacent Channel Rejection||65 dB |
|RF Gain Control (AGC)||40 dB - adjustable for optimum signal rejection |
|Squelch||Adjustable - threshold less than 0.5µV |
|Automatic Noise Limiter (ANL)||Switchable |
|Noise Blanker (NB)||Switchable |
|Receive Indicators||Meter shows relative signal strength / Receive LED glows green when receiving a signal.|
|Power Output||4 watts into PA speaker |
|Speaker for PA (Not Supplied)||8 ohms|
|Power Output||4 watts into a PA speaker |
|External Speaker(Not Supplied)||8 ohms|
Standard Features / Controls / Connectors on Radio.
* Analog Meter
* PA/AM/FM Control Selector Control
* Band A/B/C/D/ Slector Control
* RF Power Hi/Low Switch
* +10kHz / Off Switch
* NB/ANL Off Switch
* Dual 7 Segment Frequency Display
* Microphone Connector (Standard 4 Pin)
* Off/On Volume Control (Center Knob) / Squelch
* Microphone Gain (Center Knob) / RF Gain (Outer Ring)
* Talk Back (Center Knob) / Echo (Outer Ring)
* Dim (Center Knob) NightWatch & Meter / Not Channel Display / SWR Cal (Outer Ring)
* Antenna Warning Indicator
* Frequency Selector
* External Speaker Connector
* 2 Wire T-Fitting Power Cord Connector Wire
(No Standard Plug in Type Connector)
* SO-239 / Antenna Connector
* Frequency Counter Connector (FC390 / FC347 Type)
The Cobra 150 GTL DX is programmed for the 10 Meter Amateur Band out of the box, and covers a range of 28.000 - 29.700 MHz.
The frequency range can be extended for Export Use in 4 Band segments each containing 80 Channels except Band D which will contain 76 Channels.
Stock 10 Meter Frequency Coverage:
This mode is pre-set to 4 Bands with coverage of the 10 Meter Band from 28.000 MHz to 29.700 MHz.
A-Band ~ Channels 1 thru 49 = 28.000 thru 28.495
B-Band ~ Channels 50 thru 99 = 28.500 thru 28.995
C-Band Channels 00 thru 49 = 29.000 thru 29.495
D-Band ~ Channels 50 thru 70 = 29.500 thru 29.700
Export / Converted Frequency Coverage:
The Channel Display has visual indicators located on each side of the Channel Number/Display to indicate the Band Segments and the "A / Alpha" Channels.
The Band Segment Dot is displayed to the LEFT of the Channel Display and the A / Alpha Channel Dot is displayed to the RIGHT of the Channel Display and will look like this: .20.
This mode has 8 Bands divided into 4 Bands with switch positions on the radio marked A/B/C/D
Each band has two (2) 45 channel frequency blocks for each letter A/B/C/D
For example: Band "A" would start on the lower frequency segment 1~40 and then continue to the next segment when channel 40 is passed.
The channel display will show a small Red (.) dot on the Left Side of the Channel Display indicating that the radio is in the UPPER SEGMENT of the 2 Bands.
The Channel Display will look like this ~ .20
The Cobra 150 GTL DX also has "Continuous" coverage of each Band by NOT skipping the "A" channels between channel 3, 7, 11, 15, and 19.
As you reach Channel 3 the next Channel up will display the number 3 again with a small dot on the RIGHT SIDE of the 3.
The Channel Display will look like this: 3.
This will represent Channel: 3A
After Conversion Frequency Coverage:
A-Band- 26.065 - 26.505
.A-Band- 26.515 - 26.955
B-Band- 26.965 - 27.405
.B-Band- 27.415 - 27.855
C-Band- 27.865 - 28.305
.C-Band- 28.315 - 28.755
D-Band- 28.765 - 29.295
.D-Band-29.305 - 29.695
Pin #1 ~ Ground
Pin #2 ~ Microphone Audio
Pin #3 ~ Transmit
Pin #4 ~ Receive
I have added the Tune-Up Information that I have to the Copper Modification List.
At the time of my writing this Review I know of No Other Modifications for this radio.
Should any Modifications or Tips become avialiable I will keep everyone updated.
PROS & CONS
* Limited 2 Year Factory Warranty
* 2 ~ Mitsubishi RD16HHF1 Silicon MOSFET Power Transistors: Rated: Pout>16W, Gp>16dB @Vdd=12.5V,f=30MHz (Replaces older style 1969 finals.)
* Power in bench testing with power switch set to HI produced a 15 watt dead key swinging to 50 watts PEP.
* Toshiba 80 Pin TMP87PP21DF Microprocessor.
* Super Heavy Duty 10 gauge Power Cord with Automotive 10 Amp large blade type fuse.
* 2-1/8" x 3" x 7-3/4" Single Piece Solid Aluminum Heat Sink.
* SMT Components.
* PFM-0089A-BB Mother Board
* External Frequency Counter Connector located on back panel (ie: FC347 / FC-390 Type) Located under SO-239 conector.
* Style Cobra M73SL Microphone (Stainless Grill)
* 1/4" Larger / Taller Analog Meter
* This radio should be called an 8 Band Radio as you will have 8 Bands/Groups of channels after Conversion.
You will have 2 Bands/Groups of channels on each of the 4 Bands A thru D.
* No Variable Power Control just a High/Low Power Switch.
While this Cobra 150 GTL DX looks larger than the older cobras it is the same size as only the SWR/Watt Meter is slightly larger with new style control knobs.
I would personally suggest adding a FC347 or FC390 Frequency Counter as the Frequencies / Channels do not match the standard 3/6/8/10 or 12 band Frequency/Channel Charts.