I highly recommend a re-read of Jeff AC0C's comments !!!!
Frying a rcvr is easier than most think !
iow I have been there and done that, most hard lessons are not easily
forgotten :)
Buy the INRAD Book and following the recommended steps
to understanding your dbm base line
cheers!
steve
http://www.KG5VK.com
My Ham Radio Friends
On Tue, Jun 16, 2015 at 5:14 PM, Jeff AC0C <keepwalking188@ac0c.com> wrote:
> The amount of work a guy may want to put into checking out the setup for
> isolation is in direct proportion to the cost of getting a potentially
> expensive RX repaired. My view is that until you have TESTED to BE SURE
> the isolation exists, you have to assume it's going to fry gear.
>
> And don't let the thought that "I'm only running 100W" be of any
> consideration. That's +50 dBm and you want to be very much under +20 dBm
> to avoid damage - and less than that in some cases. I think W2VJN
> recommends 0 dBm as the damage threshold target. That means you need 30-50
> dB of isolation, on every band and directional combo - something which
> takes time to check out. The isolation is easy to achieve with natural
> coupling loss and a stub.
>
> You really will probably not be happy if you just try it, trusting luck
> alone, only to find out luck ends up against you.
>
> 73/jeff/ac0c
> www.ac0c.com
> alpha-charlie-zero-charlie
>
> -----Original Message----- From: Jeff Stai
> Sent: Tuesday, June 16, 2015 12:31 PM
> To: Mike Smith VE9AA
> Cc: cq-contest
> Subject: Re: [CQ-Contest] LP SO2R with no filters?
>
>
> On Mon, Jun 15, 2015 at 2:53 PM, Mike Smith VE9AA <ve9aa@nbnet.nb.ca>
> wrote:
>
> Has anyone ever done SO2R with no bandpass filters?
>>
>
>
> Buy the W2VJN book from Inrad. It will explain everything:
>
> http://www.qth.com/inrad/book.htm
>
> But in a nutshell, just try it. It sounds like you have both horizontal and
> vertical antennas, which will give you 20dB of separation at the outset.
> That could very well be enough for your conditions. If you need more, stub
> filters can be very effective for the cost of some scrap coax.
>
> 73 jeff wk6i
>
> --
> Jeff Stai ~ wk6i.jeff@gmail.com
> Twisted Oak Winery ~ http://www.twistedoak.com/
> Facebook ~ http://www.facebook.com/twistedoak
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