|
|
 |
The R390A/URR |
|
Ultimate Performance, General Coverage AM & CW Receiver |
|
|
|
Home On the WWW |
|
|
|
|
R390A/URR Receiver Site Pages Accessible from Left Hand Navigation Bar |
|
Feeding the Antenna Input |
|
|
|
Connecting an Antenna to the Input of the R390A is a subject that comes up often. The R390A has two, rear mounted antenna inputs.
One is marked ``BALANCED" and the other, labeled ``UNBALANCED." Most new R390A users will choose to feed the antenna through the ``UNBALANCED" input. Unfortunately, the receiver suffers some loss of
sensitivity. The correct choice is to fed the receiver using the ``BALANCED" input. Unfortunately, the connectors to properly accommodate this a rare and when they are found, expensive.
However, there is an easy around this dilemma. |
|
The antenna is fed into the right side of the ``BALANCED" input with with center conductor of RG8X or RG-58/U. As shown in the picture to
the right, the left side of the antenna input is grounded VIA the red wire which is inserted into the left hand pin jack and the opposite end grounded VIA the one of the 4 antenna relay assy mounting screws,
located just below and to the left of the connector. In the case of RG8X, some of the center conductor strands, usually about 3, must be removed in order for the center conductor to fit into the small
antenna input pin-jack. The co-ax is then made up in an appropriate length and terminated in a PL-259 connector for easy connection to your antenna system. After installation, best peformance is
obtained when the receiver is also aligned using this input. |
|
|
|
|
|
|
|
|
The enterprising R390A owner who is also handy with sheet metal fabrication can add an SO-239 connector to the antenna input of their
receiver. The picture at the left is simply an appropriately drilled piece of sheet metal bent at a 90 degree angle then fitted with an SO-239 connector. A .01UV ceramic disc capacitor has also
been added to provide some measure of input DC isolation.Electrically, this input functions identical to the one described above. |
|
|
