Radiating Mast
Astel Comms carry a stock range of components which enables a simple tubular steel or tubular aluminium mast to be converted to a radiating mast for the 200kHz to 28MHz MF and HF bands. (Spot frequency or tunable with appropriate antenna matching unit).
Any of the masts described in our data sheets PA2 or TS series may be converted making a very versatile range of omni directional antennas from 6-30 metres in height, in 2”, 3” or 3½” diameters. For the lower frequencies (or where mast height is a consideration) a capacity hat arrangement may be included in the design for more efficient operation.
The Astel Comms PA2 series of portable aluminium masts are particularly suited to transportable, portable or permanent use with the appropriate fittings, and the TS series masts are normally for permanent Installation.
Tubular Steel Specs
| Specs | Information |
|---|---|
| Height | 6 - 30 metres, 3" or 3½" diameter |
| Stays | HT galvanised steel wire or to customers requirements, to 120' or 90' in plan |
| Stay insert insulators | Ceramic loop stay or egg type and number to design height and power rating |
| Base insulator | 35/65kv wet/dry flashover fitted lighting spark gap arrestor, dependent upon power rating |
| Capacity hat | Normally included in stays or can be supplied separately in cadmium copper |
| Feed point | Stainless steel |
| All other fittings | Galvanised steel |
| Capacity | 450 - 1500 PFD dependant upon height and capacity hat design |
| Input impedance | 2 - 10 ohm, 50 ohm for 1/4 wave height |
Radiating Mast – Aluminium Specs
| Specs | Information |
|---|---|
| Height | 4 - 18 rnetres |
| Mast diameter | 5Omm nominal |
| Stays | Normally 6mm diameter, pre-stretched polyester or galvanised steel with insulator inserts for permanent sites. Also available in Parafil, Keviar or Philistran |
| Base insulator | 15/30kv wet/dry flashover ceramic fitted lighting spark gap arrestor |
| Capacity hat | Included in top stay, hard drawn copper elements bordered to mast sections |
| HF feed point | Stainless steel |
| Capacity | 120 - 420 PFD |
| Input impedance | 2 - 10 ohm, 50 ohm for 114 wave height |
General Specs
| Specs | Information |
|---|---|
| Frequency range | 200kHz - 28MHz to design frequency or capacity |
| Bandwidth | Normally tuneable by antenna matching unit |
| Polarisation | Vertical |
| Radiator pattern H plane | Omni-directional |
| Input impedance | Normally in the range 2 - 10 ohm but 50 ohm for 1/4 wave height |
| Power handling | Up to 30kw |