FM - TV - DX

Antenniasiaa => kaikki antenneista => Aiheen aloitti: OH5YW - Elokuu 21, 2013, 07:58:04

Otsikko: LogPer 88-108
Kirjoitti: OH5YW - Elokuu 21, 2013, 07:58:04
(http://peditio.net/dx/lp1.jpg)

(http://peditio.net/dx/lp5.jpg)

(http://peditio.net/dx/lp6.jpg)

(http://peditio.net/dx/lp7.jpg)

"The boom is constructed of two isolated square tubes, each 14mm thick. They are exactly 89 cm long. Spacing is 10mm.

On the front side (towards transmitter), there is an F-plug for the coax cable (grounding goes to the lower boom tube, inner goes to the upper tube).

On the back side, there is a small coil (without core) soldered between the two tubes: 12 windings of enameled copper wire, 10,2 mm long (0,8mm wire diameter) and 6mm coil inner diameter. Inside the coil is a resistor in parallel to the coil, so it is not possible to measure it (without de-mounting). I can barely see the colors, they are orange-blue-orange-yellow or yellow-orange-blue-orange ("orange" might also be "brown"). I suppose this resistor is for discharging static electricity.

Now to the elements:
Spacing on the booms (from the longest to the shortest element):
1: 3,5 cm from the coil end of booms (longest)
2: 29 cm
3: 51 cm
4: 70 cm
5: 86,5 cm (shortest)

Length of elements:
1: 84,5 cm
2: 72,5 cm
3: 62,3 cm
4: 53.5 cm
5: 45.9 cm

The elements are fixed on the boom by means of squeezed screws (without head = threaded bar) of 8mm diameter which is 2 cm long outside of the element. They go through the boom and the screw nut is fixed on the other side of the boom.

73
Udo, HB9ERD"
Otsikko: Vs: LogPer 88-108
Kirjoitti: OH5YW - Lokakuu 19, 2013, 07:44:37
Tässä toinen kaupallinen:

(http://www.rescueelectronics.com/sitebuilder/images/log1-775x545.jpg)

http://www.rescueelectronics.com/FM_Antennas.html