Description & Specification
The MC-750 is a 7-50MHz, 100-WATT GP antenna designed for portable applications.
For frequencies above 14MHz, it is used as a full-size (1/4 wavelength) antenna. A coil is used for 7MHz operation.
All components are packed in a 65CM x 9CM x 7CM carry bag, making it convenient for field operations.
Image Description: A blue carry bag containing the disassembled JNCRadio MC-750 antenna components, including the whip, coil, counterpoise wires, and ground rod.
Specifications
| FREQUENCY RANGE | 7MHz-50MHz |
| POWER | 100 WATTS PEP |
| IMPEDANCE | 50 OHMS |
| COUNTERPOISE | 4 X 3.5M |
| WEIGHT(KG) | 1.8 |
| DIMENSION(CM) | 65X9X7 |
WARNING: Do not power the antenna more than its PEP power ratings.
Part List
- 1 X GROUND ROD (ANT BASE ATTACHED)
- 1 X 7MHZ COIL
- 1 X 50CM ANT ARM
- 1 X 5.6M WHIP
- 4 X COUNTERPOISE WIRES (radials)
- 1 X WIRE COLLECTOR BOARD
- 1 X CARRY BAG
Installation Guide
- Connect the 50CM antenna arm to the ground rod (antenna base attached).
- Insert the ground rod into the ground, as deep as possible.
- Insert the 4 counterpoise wires into the 4 holes at the antenna base and spread them at different angles.
- For 7MHz band: Connect the 7MHz coil to the antenna arm. Skip this step if not using 7MHz.
- Connect the 5.6M whip to the antenna arm (on top of the 7MHz coil if operating on 7MHz).
Whip Adjustment: Reference marking points are printed on the whip antenna. Adjust the length of the whip to meet your desired frequency according to these markings. Sections above the mark should be fully extended, and sections below the mark should be fully collapsed. The supplied coil must be used for 7MHz band operation.
Image Description (Top): The base of the antenna showing the ground rod inserted into the ground, with the antenna arm attached and counterpoise wires connected to the base.
Image Description (Bottom Left): A close-up of the antenna whip showing a label indicating "7MHz coil needed".
Advanced Tuning and Usage
Fine adjustments to the whip antenna length may be necessary to achieve optimal VSWR readings, using an in/external VSWR meter, VNA, or antenna analyzer.
The MC-750 can be used for 10MHz and 50MHz frequencies, although markings are not provided on the whip for these bands.
- For 10MHz: Use the 7MHz coil. Fully extend the last four sections of the telescoping whip plus an additional 15cm of the fifth section. Keep the remaining sections collapsed.
- For 50MHz: Do not use the 7MHz coil. Fully extend only the last section of the whip. Keep the remaining sections collapsed.
Image Description (10MHz): Diagram showing the antenna whip extended to a specific length (indicated as 15cm) for 10MHz operation, with lower sections collapsed.
Image Description (50MHz): Diagram showing the antenna whip fully extended for 50MHz operation, with lower sections collapsed.
Important Notes on Whip Usage
- Product Quality: Each whip section is carefully printed with measurements and undergoes stretching checks. The possibility of quality issues is very low. A final inspection is conducted before shipment.
- Correct Usage Instructions:
- The whips should be attached to the antenna before extending them.
- When extending the whip, start with the thinnest section first, then gradually move to the thicker sections.
- When collapsing the whip, start with the thickest section, then move to the thinner sections, and finally collapse the thinnest section.
- Note: The whip is the most brittle part of the antenna system and requires proper protection.
Recommendations on Accessories
- It is recommended to have an antenna analyzer or VNA to read the parameters of the antenna setup.
- An antenna tuner can also be beneficial.
Support
For any problems or inquiries, please contact Chelegance support at: support@chelegance.com
HAVE FUN WITH MC-750, 73!
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