Message-ID: <002201ccef1c$c8321570$0401a8c0@xphd97xgq27nyf>
From: "mal hamilton" <g3kevmal@talktalk.net>
To: <rsgb_lf_group@blacksheep.org>
References: <002a01ccee25$c2416cd0$0401a8c0@xphd97xgq27nyf> <4F3F800B.2000201@xs4all.nl> <003e01ccee2d$49b17f50$0401a8c0@xphd97xgq27nyf> <E37CC80D85414760A1480FEB7A8F1113@AGB> <007f01ccee6c$3eca0f50$0401a8c0@xphd97xgq27nyf> <6ADDBBA8CD0B4DC38D7950C75294B505@AGB> <004601cceee8$7566da80$0401a8c0@xphd97xgq27nyf> <2AB0A82B2A6F4A0ABCD855D8AB420777@lindavideo> <000f01cceef9$bbcbe130$0401a8c0@xphd97xgq27nyf> <843575FA34474CE38D153A1E6BAB30B9@JimPC>
Date: Sun, 19 Feb 2012 15:40:17 -0000
MIME-Version: 1.0
Subject: Re: LF: opera 500
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Jim es Co
I have made no effort so far to investigate the problem since I do not use
Opera much. I do have plenty of decoupling both in the OSC/DIVIDER stages
also the LT es HT supplies to the TX MODULE.
I have several cables running into the shack from various antennas which are
quite a distance away and it could well be that one is picking up the RF
even at a vy low level and leaking it into the modem.
The modem recovers quickly after a transmission but seemingly not quick
enough to get a result from the database. It looks like this needs an
immediate response during transmission or immediately afterwards. It means I
cannot see who has copied my transmission when I stop.
I did think of putting the divider es driver into a screened box with all
power leads going to es from decoupled. That might cure it. The osc running
at 5 Mhz (Kenwood VFO 520)  is in a screened box and not a problem.

 73 de mal/g3kev


----- Original Message -----
From: "James Moritz" <james.moritz@btopenworld.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Sunday, February 19, 2012 1:48 PM
Subject: Re: LF: opera 500


> Dear Mal, LF Group,
>
> If the internet connection falls over when only the PA driver is operating
> as you descibed, the modem must be extraordinarily EMI-sensitive. I would
> suspect there is some problem with cabling and/or decoupling of the TX in
> order to cause this kind of failure. Since Opera is just a variant of QRSS
> as far as the radiated signal goes, you would certainly expect similar
> behaviour when transmitting QRSS.  But you don't seem to have much trouble
> downloading pictures of your QRSS signal from all the various grabbers and
> uploading them to this reflector, so I wonder if the problem really is RF
> related?
>
> Cheers, Jim Moritz
> 73 de M0BMU
>
>