The MFJ-1040B preselector boosts signals from 1.8 to 54 MHz. It utilizes
dual gate MOSFET, bipolar transistors for low noise and high gain.
Push-button switches provide for two receivers, two antennas, 20 dB
attenuator and ON/BYPASS. The band switch selects: 1.8-3, 3-6, 6-15 and
15-60 MHz. Controls for Delay, Gain, Band and Tune. Unlike most
preselectors, which are for receive-only, the MFJ-1040B may be used for
transceiver. It has a relay that automatically bypasses the amplifier when
transmitting. It can handle a transmit signal up to 350 watts PEP.

Rear panel jacks provide for the use of either RCA phono plugs or PL-259
connectors. Size: 6 x 2 x 6 inches. Comes with optional 12 VDC 300ma AC
Adapter.

Works perfectly but has some scratches on top. Asking $75 which includes
shipping to CONUS.

Radioman:
If you can deal with some questiosn from a neophyte SWL'er using a
TenTec RX 320

I am "apartmented" and am Using stealth antennas, short random wires,
slinkies, verticals, and wonder if such a device will be of benefit.

Is it redundant or conflict with with the active antenna of the RX 320
(I'm told it doesnt function unless RX 320 whip is in service...it isnt)

Current antenna uses home mande 9:1 balun ...will it have to be shunted
for the MFJ 1040B to work best?

My Goal to enhance signal strength and seperate overlapping signals

Yodar in orlando
(a LIVE one!)

Radioman wrote:
The MFJ-1040B preselector boosts signals from 1.8 to 54 MHz. It utilizes
dual gate MOSFET, bipolar transistors for low noise and high gain.
Push-button switches provide for two receivers, two antennas, 20 dB
attenuator and ON/BYPASS. The band switch selects: 1.8-3, 3-6, 6-15 and
15-60 MHz. Controls for Delay, Gain, Band and Tune. Unlike most
preselectors, which are for receive-only, the MFJ-1040B may be used for
transceiver. It has a relay that automatically bypasses the amplifier when
transmitting. It can handle a transmit signal up to 350 watts PEP.

Rear panel jacks provide for the use of either RCA phono plugs or PL-259
connectors. Size: 6 x 2 x 6 inches. Comes with optional 12 VDC 300ma AC
Adapter.

Works perfectly but has some scratches on top. Asking $75 which includes
shipping to CONUS.

"YODAR" wrote in message
news
Radioman:

My Goal to enhance signal strength and seperate overlapping signals

See if you can find my post about gain vs sensitivity from the other day. If
you're using substandard antennas, a preamplifier is probably only going to
increase the noise level as much as the signal level, giving you no net
gain. The idea is to separate the signals from the noise: Increase the
signal strength and at least keep the noise at the same level it was. The
preselector part of this unit isn't going to have enough selectivity to make
a noticeable difference in overall signal-to-noise ratio. A preselector is
handy when you have a receiver that picks up image responses due to poor
design. The extra tuned circuit between the antenna and the radio may help
there. Before you buy a preamp I would work on improving the antenna
situation. Frankly, your balun may not be helping very much. It may help cut
down common-mode noise, but so many of the gizmos offered to SWLs are snake
oil.

This preselector is not snake oil, and is being offered at a good price,
considering it comes with the ac adaptor. Someone interested in 13- or
11-meter (SWBC!) reception, but who is using an older, tube-type receiver,
might benefit, as would someone using a lossy antenna like a home-made loop
without built-in preamp or Beverage antenna. I'm sure someone who can
benefit from it will buy it.

You can gain as much real performance by amplifying at the audio level as at
the antenna, in many cases, and get better sound as well. Rf amplifiers are
prone to overload and, as I said, they amplify the noise as much as the
signal. If the signal is weak and noise is low, they are useful _sometimes_.
In your situation, I think you would be disappointed.

Any antenna you can get outside the apartment will be a big help. I'm using
the downspout at my condo and it works pretty well! I snuck out at night and
drilled a hole in the bottom of it, and attached a terminal lug. Inside the
porch, the wire is connected to an antenna tuner (I'm a ham) and I run
coaxial cable into the room. Cuts down on the computer hash, too.

"PM"