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Reviews Categories | Antenna Switching, Phasing, Controllers | MFJ-1708 RF Sense Transmit/Receive Switch Help

Reviews Summary for MFJ-1708 RF Sense Transmit/Receive Switch
Reviews: 5 Average rating: 4.6/5 MSRP: $79.00
Description: Automatically switches antenna between transmitter and
receiver when keyed.
Product is in production.
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You can write your own review of the MFJ-1708 RF Sense Transmit/Receive Switch.

NL7SX Rating: 4/5 Nov 5, 2017 09:37 Send this review to a friend
cheapest for the job  Time owned: 0 to 3 months
mis-labeled sockets. xceiver is middle socket. xmitant is left (first) socket. Right (last) socket is receiveant. Switching time is not fast, but might be faster with external control. Great for beverage receiving antenna. No switch to turn off unit when run on 12v.
DO9GB Rating: 4/5 Dec 29, 2014 14:01 Send this review to a friend
Good, but ...  Time owned: 0 to 3 months
Works pretty well on short wave. Use it to switch between SDR receive and FT-847 transmit.

Found no info about the supported frequency range, so I was hoping it works for 2m/70cm as well. But it does not. It switches ok, but insertion loss is tremendous.
WB0FDJ Rating: 5/5 Feb 10, 2014 20:37 Send this review to a friend
Works well and simple  Time owned: more than 12 months
I use mine for my QRP transmitter projects (think Two Tinned Tunas for example) and for running my EF Johnson Adventurer. Hook up is simple. Has never given me any trouble. I can key the relay with as little at 200 millwatts. Timing is adjustable and I'm not looking for full QSK here, just something that lets me hear between words. Relay is not too noisy at all. If you are going to run a seperate xmtr and rcvr, this is the gizmo that makes it easy.
WV4I Rating: 5/5 Nov 21, 2012 16:22 Send this review to a friend
works as advertised  Time owned: 0 to 3 months
Using this external T/R relay between an RFSpace SDR-IQ receiver and TS-590S for transmit. Its switching time is less than 25ms, which is setting for TS-590S to delay RF after PTT close. Am not getting any hint of RF back into SDR-IQ receiver (has overload light) or displayed on SDR waterfall, using SDR-Radio software. Have tested to 100W output.

Another convenient feature is this unit has an extra PTT output (RCA) that goes to ground on transmit, could be used to key amp downstream of relay, eliminate need for separate amp relay.

It is operated by RF sense or hard key PTT line.

Exactly what I needed to isolate transceiver for transmit and SDR for receive, on same antenna. (TS-590S is synched to SDR-Radio re freq and mode)
N4LQ Rating: 5/5 Mar 16, 2012 15:00 Send this review to a friend
Really works great  Time owned: 0 to 3 months
I'm using this with a DX-60 and HQ-150. I use the aux jack to mute the speaker. The response and change over time is so fast that no one detects any contact bounce or dit shortening. You can adjust the delay time down to zero so it's like QSK if you aren't bothered by relay noise. I usually leave enough delay to hold it between cw letters.
Isolation seems very good between rx and tx.
excellent product.

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