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Reviews Categories | Receive Pre-amps | J-TEC ASAP-2 Antenna Switch and Preamp Help


Reviews Summary for J-TEC ASAP-2 Antenna Switch and Preamp
J-TEC ASAP-2 Antenna Switch and Preamp Reviews: 1 Average rating: 5.0/5 MSRP: $149 shipped
Description: The ASAP-2 provides the user the ability to select 1 of 5 different receive antennas and adjust the signal gain to suit most HF band conditions over the 1.8-30 MHz range.
Product is in production.
More info: http://www.j-tecradio.com
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K8AC Rating: 5/5 Dec 25, 2005 06:45 Send this review to a friend
Unique combination of features  Time owned: 0 to 3 months
This is an interesting unit, in that it combines a receive preamp and the ability to connect up to 4 different receive antennas to a transceiver that doesn't provide for a separate receive antenna. It is designed to connect between the HF transceiver antenna connector and transmit antenna and includes a T/R relay so that the selected receive antenna and preamp are in the line on receive, but the transmit antenna is inline on transmit. If you use an HF amp, then the unit goes between the transceiver and amp input.

The preamp has a three position gain switch (+20dB, 0 dB, -20dB) to accomodate the characteristics of the receive antenna in use. The preamp can even be used with the transmit antenna, providing some needed gain on the higher bands (up to 10 meters) for those older transceivers that don't have a built-in preamp (the Drake TR-7 for example). If your transceiver does have a connection for a receive antenna, this unit could be installed there.

The unit is housed in a plastic case, not my first choice for circuitry that's carrying the transmitted signal, but I've not noticed any problems attributed to that. The ASAP-2 requires a connection to your transceiver's PTT line so it can switch the transceiver output to the transmit antenna on transmit. Should you happen to NOT provide that connection and transmit into the ASAP-2, you could zap the preamp. Thorough testing of the operation prior to applying transmit RF is in order and a TX LED on the front panel informs you of proper operation of the PTT line.

Note that the preamp in the ASAP-2 has a low noise figure and functions from 1.8 - 30 MHz (100KHz to 35 MHz at reduced specs) so it's very useful just as a preamp on the higher HF bands. I've found that it provides improved S/N ratio for my Drake TR-7 on 20 through 10 meters as the TR-7 doesn't have a preamp.

My unit developed a problem in the relay circuit after a few minutes of operation and I had to return it to the manufacturer. It was back in my hands in just 8 days (including shipping time) and has since worked perfectly. Another piece of station gear had to be returned for service to another manufacturer on the same day and I've not heard from them yet (10 days later!).
 


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