Glenn Hauser's SW/DX Report
Continent of Media
Don Schimmel's Radio
Joe Carr's Tech Notes
Frequency vs. Wavelength
Modes and Modulation
Call Sign Prefixes
Introduction to Shortwave
Tuning 150 kHz to 30 MHz
Selecting a Shortwave Radio
Reporting and QSLs
Modern Shortwave Receiver Survey
Favorite Tube-Type Shortwave Receivers
Introducing the "Action
The World Above 30 MHz
Selecting a Scanner
National Scanner Frequency
Other Radio Hobbies
AM Band DXing
Top of Page
|General Coverage Broadcast Receiver
|Made In: England 1953-1960
||Voltages: 110/200/230 VAC or 110/200/230 VDC
|Coverage: 150-380, 540-30000 kHz.
|Circuit: Single Conversion Superheterodyne. 6 Tubes plus Semis.
Circuit Complement: UAF42 RF Amplifier, UCH42 Frequency Changer, UAF42 IF Amp/AGC, UAF42
Detector/Audio, UL41 Audio Output, DM70 Tuning Indicator plus a diode rectifier.
Features: • Speaker Output • Dial Lamp • Rack Handles • Tuning Indicator
• Speaker • Phono Input • Vernier Tuning • Log Scale 0-2500 • Tone • Flywheel Tuning
Accessories: 732 Mains Filter
|New Price: ?
||Used Price: £80-100
Comments: The 670 series was expressly designed for ship board cabin use. The 670A has five ranges: .15-.38, .54-1.5 3.7-10.6 and 10.5-30 MHz. The fifth "range" is marked "G" which is for a gramophone (phonograph) input. The broadcast bands are marked on the dial. The vernier tuning scale is a mechanical bandspread scheme that provides a quick and accurate means to return to a previously logged frequency. The tuning indicator (DM70) is a green fluorescent tube. With no signal the glow will extend to its full length. When a signal is received the glow contracts.
Variants: The earlier model 670 was introduced in 1948 (£37-40 new) and had 7 tubes. The original 670 had the medium wave scale marked in meters.
|General Coverage Communications Receiver
|Made In: England 1952-1962
||Voltages: 110/125 200/250 VAC
40-60 Hz 80W
|Coverage: 480 - 30000 kHz.
||Selectivity: 6/3/1.3 kHz -6dB.
|Circuit: Single Conversion Superheterodyne. 15 Tubes.
||Physical: 16.75x8.75x15" 47 Lbs.
426x222x381 mm 21.3 kg
Circuit Complement: 6BA6 RF Amp, 6BA6 RF Amp, 6BE6 Mixer, 8D3 Local Osc, 6BA6 IF, 6BA6 IF, 6AL5
Detector/AVC, 6BR7 AF, 6BR7 AF, 7D9 Audio Amp, 7D9 Audio Amp, 6BA6 BFO, 6AL5 S-Meter/NL, 5Z4QT Rectifier and VR150 Voltage Stabilizer. Two RF stages
and two IF stages. Crystal filter.
Features: • ¼" Head. Jack • S-Meter • Rack Handles • Calibrator 100 kHz
• RF Gain • BFO ±3 kHz • Mute • 140:1 Tune Ratio
• Standby • NL • Dial Lamp • Dimmer (back panel)
• AVC ON/OFF • Flywheel Tuning
Accessories: 812 Mounting Feet, 811 Diecast Speaker, 688 Speaker Black
|New Price: £106-140
||Used Price: £90-160
Comments: The 680X replaced the similar 680/2. The 680X has a 6BE6 for V3 rather than the
7S7 found in the 680. It also adds a crystal filter and product detector. Ranges: .48-1.12, 1.11-2.5, 2.5-5.7, 5.3-
12.5 and 12.3-30 MHz. Note headphone jack on the side.
Variants: Model 680X/RM is for rack mounting.
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