Yes, Frank did indeed tell me that, Mario.
I am not concerned in this case about damage to the receiver, which I am
dealing with otherwise. The problem I want to address is that when I
transmit on 20, the receiver on 10 is wall-to-wall with my own signals.
Same is true, I'm sure, on 40/20, 80/40 and 160/80. This prevents my
copying stations while I'm transmitting, causes Skimmer to spawn many
spurious decoders, and eventually results in spurious spots (mis-copies
of my call).
I've gotten a lot of helpful input from guys on this reflector. Thanks,
everyone, and let's let the reflector get back to its intended topics.
73, Pete N4ZR
The World Contest Station Database, updated daily at www.conteststations.com
The Reverse Beacon Network at http://reversebeacon.net, blog at
reversebeacon.blogspot.com,
spots at telnet.reversebeacon.net, port 7000
On 12/30/2010 7:31 PM, S56A wrote:
> N4ZR wrote: From what W3LPL has told me, I am pretty confident that I can
> simply parallel the output of the 6 filters, but can I also parallel the
> inputs?
>
> I very much doubt that W3LPL told you that! His BPF are triple tuned
> circuits with top capacitor coupling. They exhibit low impedance on the
> frequencies above bandpass. 10 m filter is coupled to 50 Ohms with 33 pF
> while 160 m has 719 pF. That gives 475 (square) power ratio or -27 dB
> loss.
>
> Only serial tuned circuits can be paralleled at 50 Ohms and even that
> becomes difficult beyond triplexer. Check http://www.nuhertz.tv/
>
> You don't need any BPF for QS1R, just band STOP filters to prevent input
> frying from nearby TX. ICE filters might be easily converted to band-stop
> with change of both inputs to serial notch and adding just one more small
> coil for parallel resonance (de)coupling.
>
> HNY& 73 de Mario, M/S56A from London
>
>
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>
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