That is a very good tip, Carl.
Reminds me of the old Johnson T/R switch I used 50 years ago (hi).
My only comment is, one should absolutely NOT use the RF sense for switching
when working in CW.
That could end up being too slow and blow the 2nd RX.
It is fine for SSB using PTT.
Not sure how it would be using SSB and VOX.
I guess that would depend on how loud you say your first "uuuhhh".
With any of the late model Ten-Tec transceivers (ORION, OM7, Eagle), the
delay after keying the PTT is plenty long to allow the 1708 to switch.
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Carl
Moreschi
Sent: Sunday, November 09, 2014 4:26 AM
To: Don Rasmussen; Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] OT: Holiday SDR Project
What radio are you using? Many radios have an easy way to share antennas.
If that's not an easy solution then the MFJ1708 can do the job. See below.
The solution to share antennas is to add an MFJ-1708 T/R switch. This
unit will automatically sense RF from the transmitter and then remove
the panadapter radio from the receive antenna connection. But the MFJ
switch will also remove the transceiver from the transmit connection
while in receive. So the MFJ switch needs a very simple mod. You
must solder a 14 gauge wire between the transmit and antenna SO-239
connections. This will then make the switch operate properly for this
use. Additionally, you can wire the relay to energize from your
radio's amp key line for faster and safer switching.
Carl Moreschi N4PY
58 Hogwood Rd
Louisburg, NC 27549
www.n4py.com
On 11/7/2014 5:45 PM, Don Rasmussen via TenTec wrote:
>
>
> That sounds great Carl, the transceiver and SDR can both be tuned by the
main tuning knob of the transceiver.
>
> Anyone have suggestions on sharing the antenna?
>
> The second receiver needs to have it's input grounded before the
transceiver puts RF on the line.
>
> =======================================================
>
> That will work well for you. My N4PY software can provide everything you
need to keep the softrock and your transceiver on the same frequency.
> Carl Moreschi N4PY
> 58 Hogwood Rd
> Louisburg, NC 27549
> www.n4py.com On 11/5/2014 11:34 AM, Don Rasmussen via TenTec wrote:
> After all this talk about the new Flex Series and peripherals it seems
> all of my objections have melted away except for the oldest one -
> cost! Flex 6300 with FX-PAD and TMate2 are outside of my ham radio
> budget but only because I have that amount of money tied up in
> existing gear that I enjoy. I did decide to take a look at what Tony
> Parks has been up to and found a very inexpensive SDR project for the
> holidays. I can enjoy the build and then mess with the software. The
> 1.8-30Mhz receiver is $68 and the option cabinet is $20.
> http://tinyurl.com/qx4ha8p
>>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
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