This time HamTenna will see itself as a customer … with a project for the new station that will be born in 2021.
Let’s start with a BigBoy Prosistel rotator … an initial revision and a new pair of oversized gear wheels …
|Wind load area||4.1 m2||44.1 sq/ft|
|Rotating torque||3800 Kg/cm||3300 in/lb|
|Braking torque||29000 Kg/cm||2100 lb/ft
|Vertical load||850 Kg||1870 lb|
Work in progress: the rotator has been opened and I have checked the condition of the tapered bearing (perfect), the oil level and the condition of the seals.
No signs of wear were detected.
The external body of the engine and the transmission part was sandblasted, cleaned with a specific 3M product and painted with “thermo 800°C” paint, finally two coats of Plastidip spray were applied.
The pinion of the rotation plate has been greased abundantly and the old ring gear has been removed to be replaced with a larger one.
The electrical contact compartment has also been cleaned and all connections have been checked.
The old 7x1mm cable has been removed and will be replaced with a new fitting up to the control box located near the rotor.
BigBoy restored and tested :
What about antennas ?
The project will start with the HF Tower-1, a 9mh tower with coax elevator for EME 144MHz and a small tower for EME 430MHz.
Tower-1 will be 29mh base rotating and it will support the main antennas for 10/15/20m: a pair of 4/6/14 (4el @ 20m – 6el @ 15m – 14el @ 10m) with 15m boom eachone.
these yagis will be realized with 3 differend coax fed lines and stacked with 3 different stack matches.
At the top a 3 el full size for 30m band… In addition fo 17/12m a pair of 4/5 (4el @ 17m – 5el @ 12m) on 7.5m boom each.
Also this two yagis will be realized with 2 different feed lines and stacked with 2 different stack matches.
- 30m : 3 el fullsize yagi
- 20m : 4+4 el fullsize stacked, a stack-match will allow the selection A, B, A+B.
- 17m : 4+4 el fullsize stacked, a stack-match will allow the selection A, B, A+B.
- 15m : 6+6 el fullsize stacked, a stack-match will allow the selection A, B, A+B.
- 12m : 5+5 el fullsize stacked, a stack-match will allow the selection A, B, A+B.
- 10m : 14+14 el fullsize stacked, a stack-match will allow the selection A, B, A+B.
Tower-2 will be a 20mh fixed tower with top rotator and will keep at the top an Ultrabeam UB-50 for 6-40m.
It will be feeded by Cellflex 1/2″ until the top of the tower, then LMR-600 soft connection.
Tower-3 will be a 9mh elevator tower for 2m EME, will keep 4x 28el crossed yagis by Antennas-Amplifiers AZ+EL
It will be feeded by Cellflex 7/8″ until the top of the tower, then LMR-600 soft connection.
Tower-4 will be a 15mh tower for 144/430 tropo antennas: will keep 9+9 H @ 144 and 25+25 H @ 430