On 9/23/2020 3:06 AM, Pimpom wrote:
On 9/23/2020 1:02 PM, Pimpom wrote:
On 9/23/2020 3:26 AM, Dave Platt wrote:
Stu jaxonÂ* wrote:
Hi Group, can someone help please, I have an antenna booster that
requires a power supply of 6v 100ma, can i use a
variable power supply 6v 300ma???

Assuming that they're both DC supplies, and assuming that you get the
polarity correct (positive-supply to positive-load, negative-supply to
negative-load), and assuming that you're careful to not turn the
variable power supply up to higher than 6 volts... yes, it should
work.Â* The 300 mA capacity of the variable supply is greater than the
100 mA which the booster will draw, and that's OK.Â* However, turning
up the supply to above 6 volts may damage the booster.Â* I'd recommend
checking the supply voltage with a voltmeter before you connect it to
the booster.

Do be aware that "antenna booster" amplifiers can cause more problems
than they solve.Â* In most cases you'll get better results by improving
your antenna setup.

Agreed on all points except that, in certain situations, using an
antenna booster is the only way to get an acceptable reception.

TV came to this remote corner of India in 1980 when some army
people discovered that it was possible to receive stations in
neighbouring Bangladesh. Due to the very hilly terrain, reception
varied from fair to unusable within tens of meters, all with
outdoor yagi antennas. Antenna boosters were a must.

The boosters were all alike, made up of 4 or 5 bjt amplifier
stages. Power was fed to the booster via twin 300-ohm cable from
an indoor 12V AC supply and gain was adjusted by means of a
series potentiometer.

I was the local "expert" and I experimented with different
antenna types, including yagi arrays and helical antennas with a
6-foot plane reflector. Some people claimed that reception was
noticeably improved by hanging aluminium pans on their yagis.

Once I even rigged up a passive re-radiator with a back-to-back pair of
yagis on a hilltop for a client who had no reception at all in his house
which was located on the blind side of the hill. It worked somewhat but
was not really satisfactory.

What I couldn't really explain was that reception slowly but steadily
degraded in the decade from 1980 to 1990 (when cable TV arrived). In
1980, I could often get excellent reception in my house with literally
an aluminium coat hanger plugged into the antenna socket. By contrast, I
could watch the 1990 FIFA World Cup only with an array of four yagis
*and* an antenna booster.

Is it possible there was construction going on somewhere between the
source antenna and your work?