Hills Prolink 1B TV distribution amplfier
Today, I bought a Hills Prolink 1B TV distribution amplifier made in 1992 and when I was testing it, I got a lot of hum.
So I decided to replace both electrolytic capacitors (the original 470uF/25V Samwha unit before the 12V regulator measured at about 49uF) with an upgrade of the 470uF/25V unit to a 2200uF/25V unit (it had a higher capacitance density than the original) along with the 10uF 35V low leakage unit on the 12V rail being replaced with a 22uF 16V tantalum unit.
This fixed the problem and the amplifier still has a good noise figure.
Could this unit have been in a hot area, such as in the roof space?
Heat apparently causes MATV equipment to fail, especially those with switching power supplies.
So I decided to replace both electrolytic capacitors (the original 470uF/25V Samwha unit before the 12V regulator measured at about 49uF) with an upgrade of the 470uF/25V unit to a 2200uF/25V unit (it had a higher capacitance density than the original) along with the 10uF 35V low leakage unit on the 12V rail being replaced with a 22uF 16V tantalum unit.
This fixed the problem and the amplifier still has a good noise figure.
Could this unit have been in a hot area, such as in the roof space?
Heat apparently causes MATV equipment to fail, especially those with switching power supplies.