The manual provides instructions for modifying the Radio Receiver BC-779 to include a quick-disconnect antenna feature by replacing screw-type terminals with a coaxial connector, detailing steps such as removing side plates and drilling mounting holes. It specifies that the modification should be performed during depot-level maintenance and requires approximately two man-hours to complete.

• Brand: Hammarlund
• Model: MODIFICATION
• Type: manual
• File size: 97.9 KB

Manual Overview

The manual details the modification of the Radio Receiver BC-779 to include a quick-disconnect antenna feature, replacing screw-type terminals with a coaxial connector SO-239. This modification is to be performed during depot-level maintenance. The process involves removing the existing antenna terminal strip and unsoldering the attached wire. The SO-239 connector is then mounted by drilling four holes in the back plate, using the connector as a template. The wire previously unsoldered is soldered to the new connector, which is secured with machine screws and brass nuts. The removed side plates are then replaced. The modification requires specific parts, including the SO-239 connector, machine screws, and brass nuts, all of which should be requisitioned from the Rome Air Force Depot. Approximately two man-hours are needed to complete the modification. No special tools are required for the installation. Removed parts, such as the antenna terminal strip, are to be condemned and tagged for disposal.

Quick Issues Covered

• Quick-disconnect antenna modification for BC-779 receiver.
• Instructions for replacing antenna terminals with SO-239 connector.
• Modification requires depot level maintenance and specific parts.

Overview

This document is a technical order from the United States Air Force detailing the modification of the Radio Receiver BC-779 to include a quick-disconnect antenna feature. The modification involves replacing screw-type terminals with a coaxial connector, SO-239, to allow for rapid connection and disconnection of the antenna. The work is to be accomplished during Depot Level Maintenance, and specific parts and procedures are outlined for the modification process.

Specifications

• Radio Receiver BC-779
• Connector: SO-239
• Machine Screw: RH 4-48 x 3-in
• Nut: 4-48, plain, brass
• Man-hours required: Approximately two

Controls & Indicators

Refer to the PDF for details.

Installation / Setup

The setup involves replacing the screw-type antenna terminals on the Radio Receiver BC-779 with a coaxial connector SO-239 for quick-disconnect capability. The process includes removing side plates and the antenna terminal strip, reaming and drilling holes for the new connector, soldering wires, and fastening the connector with screws and nuts. No special tools are required, and the modification takes approximately two man-hours.

Operation

Refer to the PDF for details.

Troubleshooting & Error Codes

Refer to the PDF for details.

Safety & Warnings

Refer to the PDF for details.

Download MODIFICATION Manual (PDF – 97.9 KB)

Hammarlund BC-799 Air Force MODIFICATION manual: Guide for implementing technical modifications. File size: 97.9 KB.

• Brand: Hammarlund-bc-799-air-force
• Model: MODIFICATION
• Type: Manual
• File size: 97.9 KB

Overview

Brief overview of the product.

Specifications

• Key spec 1
• Key spec 2

Controls & Indicators

Control panel/button layout.

Installation / Setup

1. Step 1…
2. Step 2…

Operation

Basic usage, modes, cycles.

Troubleshooting & Error Codes

Safety & Warnings

• Important warning…

Downloads

Download MODIFICATION manual (PDF)

The manual provides instructions for modifying transmitters, specifically the T-4 series, to integrate VHF equipment by disabling the screen grid circuit and adding a low-level output. It includes detailed steps for drilling holes, mounting fittings, and making electrical connections, as well as guidance on retuning the equipment and troubleshooting modifications.

• Brand: Drake
• Model: MODIFICATION
• Type: manual
• File size: 410.8 KB

Manual Overview

The Drake MODIFICATION manual outlines the necessary steps for modifying transmitters to integrate VHF equipment, specifically focusing on the T-4 series. The primary modification involves disabling the screen grid circuit of the final amplifier for six-meter operation and adding a low-level output of 0.25V. Technicians are instructed to drill three 1/4 inch holes in the rear chassis for mounting phono fittings. The manual provides detailed guidance on wiring modifications, including removing a jumper wire between the relay printed circuit board and the feed-thru capacitor, and connecting wires from the P.A. disable jack to the feed-thru capacitor and relay printed circuit board. Capacitors are to be installed to ground from the P.A. disable jacks. A two-lug terminal strip is installed, connecting a 2.0 pf capacitor and a 47-ohm resistor, with coax cable linking to the exciter output. All connections must be soldered, and the twenty-meter trimmer should be retuned as per the transmitter manual.

Quick Issues Covered

• Disable screen grid circuit for six meter operation.
• Add low level output with specific wiring modifications.
• Circuit tracing: Refer to schematics for phono fitting locations.

Overview

Refer to the PDF for details.

Specifications

Refer to the PDF for details.

Controls & Indicators

Refer to the PDF for details.

Installation / Setup

Refer to the PDF for details.

Operation

Refer to the PDF for details.

Troubleshooting & Error Codes

“”

Safety & Warnings

Refer to the PDF for details.

Download MODIFICATION Manual (PDF – 410.8 KB)

Drake-t-4x-4xc MODIFICATION manual PDF (410.8 KB) guides technicians through modification procedures for the model.

• Brand: Drake-t-4x-4xc
• Model: MODIFICATION
• Type: Manual
• File size: 410.8 KB

Overview

Brief overview of the product.

Specifications

• Key spec 1
• Key spec 2

Controls & Indicators

Control panel/button layout.

Installation / Setup

1. Step 1…
2. Step 2…

Operation

Basic usage, modes, cycles.

Troubleshooting & Error Codes

Safety & Warnings

• Important warning…

Downloads

Download MODIFICATION manual (PDF)

The manual for the Kenwood R1000 shortwave receiver covers the installation of a DRM mixer, detailing its connection to the last IF buffer and the power connection points. It also includes specifications, schematics, and a spectrum output analysis, though the receiver's performance with the software has not yet been tested.

• Brand: Kenwood-r-1000
• Model: MODIFICATION
• Type: manual
• File size: 331.1 KB

Manual Overview

The Kenwood R1000 modification manual provides detailed instructions for integrating a DRM mixer into the shortwave receiver. The mixer, sourced from Sat. Service Schneider in Germany, operates at 467 kHz and includes a crystal option. The modification involves connecting the mixer to the last IF buffer of the receiver at the junction of R148 and the emitter of Q24, referred to as point A. The power connection is established at point B. The DRM modulator output is linked to the antenna input of the Kenwood receiver with a 40 dB attenuator, and the output spectrum is recorded for evaluation. The manual includes a schematic, mounting picture, and output spectrum for reference. It notes that the receiver’s performance with the software has not yet been tested, and updates will be provided upon completion of testing. The manual does not include specific troubleshooting flow, error codes, or calibration procedures, focusing instead on the physical modification process and initial setup.

Quick Issues Covered

• Diagnose power-up failures at IF buffer connection point A.
• Calibrate DRM mixer output using a 40 dB attenuator.
• Trace circuit using schematic for R148 and Q24 connections.

Overview

The Kenwood R1000 shortwave receiver has been modified with a DRM mixer from Sat. Service Schneider in Germany. The mixer is a 467 kHz type with a crystal option, connected to the last IF buffer in the receiver. The modification includes a power connection and a DRM modulator output connected to the antenna input with a 40 dB attenuator. The output spectrum has been recorded, but the receiver has yet to be tested with software. The document includes the Wavetek Model front page, specifications, schematic, mounting picture, and output spectrum.

Specifications

• Frequency Range 190 kHz – 30 MHz
• AM, CW, SSB Modes
• Sensitivity 0.5 µV
• Selectivity 6 kHz (-6 dB), 2.7 kHz (-6 dB)
• Intermediate Frequency 455 kHz
• Audio Output 2 W
• Power Supply 120/220 V AC, 12 V DC
• Dimensions 330 x 130 x 270 mm
• Weight 7 kg

Controls & Indicators

Refer to the PDF for details.

Installation / Setup

The installation and setup of the modified Kenwood R1000 shortwave receiver involve connecting a DRM mixer to the last IF buffer in the receiver at the connection of R148 with the emitter of Q24. The power connection is made at a designated point B. Additionally, the DRM modulator output is connected to the antenna input of the Kenwood receiver with a 40 dB attenuator inserted. There are no specific details provided about wiring, clearances, or calibration in the source document.

Operation

Refer to the PDF for details.

Troubleshooting & Error Codes

Refer to the PDF for details.

Safety & Warnings

Refer to the PDF for details.

Download MODIFICATION Manual (PDF – 331.1 KB)

Kenwood-r-1000 MODIFICATION manual PDF (331.1 KB) guides technicians through modification procedures for optimal performance.

• Brand: Kenwood-r-1000
• Model: MODIFICATION
• Type: Manual
• File size: 331.1 KB

Overview

Brief overview of the product.

Specifications

• Key spec 1
• Key spec 2

Controls & Indicators

Control panel/button layout.

Installation / Setup

1. Step 1…
2. Step 2…

Operation

Basic usage, modes, cycles.

Troubleshooting & Error Codes

Safety & Warnings

• Important warning…

Downloads

Download MODIFICATION manual (PDF)