Product Details:

Scientific Radio Systems SR-204 Front Panel & Chassis Frame. This was the beginning of the assembly process for building a 100 watt, 1.6 to 30 MHz, 6 channel crystal controlled transceiver. Their beginning is your avenue to high power from your home brew or kit QRP rig to a professional looking rig. All the hard part of homebrewing is done. Just mount your board(s) in the frame and make interconnections to the front panel controls and rear panel connectors. Matching set of knobs included.

Included on the front panel are the controls, switches, jacks and a lighted 0 - 1 mA meter marked in "S" units and watts. An ancillary board for setting individual transmit audio levels for each channel is mounted and includes six 10k ohm trimpots and miscellaneous parts.

The complete receive audio board that takes output from the detector and boosts it to up to 6 watts out into the 4 ohm speaker is also mounted on the front panel and is included. No more headphones only listening. Also on this board are the transmit tone oscillator for tune up of an SSB transmitter, 2 matching line inputs from 600 ohm balanced feeds, one for transmit audio, the other for receive audio and the T/R relay driver.

Also in this frame is the majority of the high power RF deck. This deck was designed to use two 6LQ6 sweep tubes (not included) driven by an MJE340. The MJE340 was driven by a 2N1613 from another board (not included) which is a general purpose 1/2 to 3 watt transitor All parts for the RF deck are included except: two 6LQ6 tubes, 4PDT, 12 vdc, T/R relay and the tank circuit (coil and variable capacitors). It also includes a calibrated RF sampler used to drive the front panel meter through existing wiring on the chassis.

The front panel channel switch extends though the RF compartment and could be used to select pre-tuned tank circuit taps and capacitors. The switch is a 7 pole, 12 position switch with 3 poles in the RF compartment and 4 in the front panel compartment. An alternative is to remove the channel switch for a single band radio and mount the frequency tuning control in its place.

In the original design, this radio included the power supply in the frame to provide all required voltages from either 115 / 230 vac or 12 vdc. If you want to use the 6LQ6 finals, buy the optional power supply of your choice below. Or, gut the RF deck and install you own solid state PA - no power supply needed. A 3-5/8" externally mounted square fan is required for high power operation. A suitable unit is listed on our MUFFIN FANS page.

A full manual for the SR-204 is included with each unit.

Select from the SR-204 which has a gray silk screened front panel with handles or the SR-204D (below) which is olive drab with no handles. Internally they are the same.

• External dimensions: 13-3/8" wide x 15" deep x 4-1/4"H
• Internal dimensions:
  • Power Supply section: 6-1/4" x 6-1/4"
  • Receiver Section: 4" x 6-1/4"
  • PA Compartment: 6-1/4" x 6"
  • Exciter Section: 4" x 5"

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