| Home |
| Search |
| Today's Posts |
|
#16
June 14th 09, 12:22 AM
posted to rec.radio.amateur.antenna
|
|||
|
|||
Cassegrain Antenna Development
"Emanuele Colucci" wrote in message ... Thanks to James for the advices and to Jerry and Jim for the news. Jerry: I'd like to know more about your solution, if you agree.  Jim Lux ha scritto: There's a set of articles in IEEE Antennas and Propagation Magazine (not the transactions) a few years back that has all the equations and design rules for all of the various reflector configurations. Where I can find these articles? Best wishes, Emanuele Colucci Hi Emanuele I submit that, if you intend to actually build an antenna for L-Band and are restricting its diameter to 3 meters, you need not consider a cassegrain feed. The reflector at the focus is too small to allow the primary feed to illuminate it with a high percentage of the available source at the rear of the dish. For one example, let the cassegrain reflector be 1/2 meter diameter and be spaced 1meter from the apex of the dish. Wouldnt that suggest that the primary beam, from behind the dish will have a beamwidth of about 30 degrees (at -3dB)?? If the cassegrain reflector is made bigger, that blocks more of the parabolic dish apperature. If the cassegrain reflector is made smaller, that increases the need for a high gain primary feed. It is my contention that, if you want to research Cassegrain antennas, that is a worthy project. If you want to build a functing L-Band telescope with 3 meter dishes, dont include cassegrain feeds in the project. Jerry KD6JDJ |
| Thread Tools | Search this Thread |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Forum | |||
| Cassegrain Antenna development | Homebrew | |||
| Software Development Questions | Scanner | |||
| Development of APRS | Digital | |||
| Development of APRS | Digital | |||
| Subreflector of Cassegrain dish | Antenna | |||
![Jerry[_5_] is offline](https://www.radiobanter.com/images/SultanThemeVB3R/statusicon/user_offline.gif)
Threaded Mode
