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Reviews For: Treetop Circuits SB 390 Product detector for R-390A

Category: Receivers: Amateur Radio

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Review Summary For : Treetop Circuits SB 390 Product detector for R-390A
Reviews: 1MSRP: 95
Description:
Similar to the SB-51, with wide dynamic range and a dual time constant AGC circuit. In AM mode, the adapter is switched out of the circuit entirely, so performance on AM is unchanged
Product is in production
More Info: http://treetopcircuits.com
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0015
K1QAR Rating: 2013-12-18
excellent piece of engineering Time Owned: more than 12 months.
Like the SB-51, this gives modern transceiver sideband performance. Installation is directly onto to the back terminal strip by replacing three screws with standoffs. Three wires are poked into the IF deck and soldered (Poke first, then strip), and two wires replace the AGC jumper on the back terminal strip. The radio can thus easily be returned to original.

As with the SB-51, sideband is tuned just like a modern transceiver, with the bandwidth set at 2Kc just tune for maximum noise, then adjust the BFO for intelligible audio.

For synch AM, I actually find temporary use of the limiter very handy for quickly finding zero beat, since it interacts with the BB-390 to somehow enhance the BFO tone.

In sum, by far the best single accessory/mod I've found for the legendary R-390A