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#11
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"Pete KE9OA" wrote in message ... Hi Lucky, It was ok.................. not a lot of gain in the I.F. system, but it did have enough RF gain. It is probably a matter of preference, but I like my radios to have their gain distribution set up so that the I.F. strip provides most of the system gain. This way, you get a higher amount of headroom in the front end if the gain in that section of the receiver isn't too high. It did work better than any of the portables I have used. I bumped up the gain in the I.F. strip a little bit, and I was relatively happy with it. I ended up trading it off in a combination deal for a Yaesu FRG-100, which I ended up selling along with the optional CW filter and the FM board for 300 dollars. Some older fellow in one of the Carolinas bought it. Pete Hi Pete would you say it's more a portable wise type perfromance? What did you do with yours? Anything decent about it?? Lucky Well Pete, if you didn't end up keeping it that does say something about it. I just get a kick out of new radios especially foreign ones. Could they have improved them somewhat since you bought one? Was it the Lowe SRX-100 or the Nasa Target HF3? Lucky |
#12
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"Brian Denley" wrote in message ... Lucky wrote: Hi guys! I saw this term mentioned in the specs of a radio. What does it mean exactly? That if you hope and listen long enough you can convince yourself it's synchronous? Lucky I'm quasi-synchronous....sometimes! -- Brian Denley http://home.comcast.net/~b.denley/index.html I knew a guy who was Quasi-Moto Lucky |
#13
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jimg wrote:
in basic comm text books this is called is called 'coherent' detection. under certain conditions it can be demonstrated that the coherent demodulated snr is a 3-4 dB better than the "diode" (non-linear self-mixing) demod and a 3-5 dB worse than synchronous demodulation. under severe fading the coherent demod can actually underperform the diode demod depending upon the mixer/post-filter/etc. whereas the synchronous pll output can maintain the mixer input even if the signal disappears briefly (wrt the loop time constant and phase detector type) because of the fading performance, the ease creating high quality quadrature pll outputs, and the inherent input phase noise attenuation in the pll, it's (coherent demodulation) almost never used anymore in mixed signal designs... Hi guys! I saw this term mentioned in the specs of a radio. What does it mean exactly? That if you hope and listen long enough you can convince yourself it's synchronous? Lucky jimg Oregon USA |
#14
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A sync detector does not have to be a sideband-selectable type to be
a what would be referred to as a true type of sync detector. It does need to be a PLL type, though. Pete This is true, of course, but a sync. detector in modern equipment that is not sideband-selectable for the SW environment, where there's often so much adjacent channel interference, is a perversity. RK |
#15
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rkhalona wrote: A sync detector does not have to be a sideband-selectable type to be a what would be referred to as a true type of sync detector. It does need to be a PLL type, though. Pete This is true, of course, but a sync. detector in modern equipment that is not sideband-selectable for the SW environment, where there's often so much adjacent channel interference, is a perversity. You're a 'newbie'... right? My oh my, what did one ever do without 'synch'. dxAce Michigan USA |
#16
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True........most people are looking for that characteristic.
Pete "rkhalona" wrote in message oups.com... A sync detector does not have to be a sideband-selectable type to be a what would be referred to as a true type of sync detector. It does need to be a PLL type, though. Pete This is true, of course, but a sync. detector in modern equipment that is not sideband-selectable for the SW environment, where there's often so much adjacent channel interference, is a perversity. RK |
#17
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In article .com,
rkhalona wrote: A sync detector does not have to be a sideband-selectable type to be a what would be referred to as a true type of sync detector. It does need to be a PLL type, though. Pete This is true, of course, but a sync. detector in modern equipment that is not sideband-selectable for the SW environment, where there's often so much adjacent channel interference, is a perversity. Why is using an I/Q "Image reject" mixer better than just having a narrower filter? As I understand it, you're not going to get more than 50 dB rejection with an image reject mixer. Mark Zenier Washington State resident |
#18
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In article ,
Pete KE9OA wrote: "John S." wrote in message oups.com... Which radio...haven't heard that term. I believe that Kiwa detector that went on eBay recently was of this design. A guy I know who knows Craig a lot better than I do said that it used some chip designed for VCRs. (My wild ass guess would be a Philips video IF and detector chip with the synchro-phase circuit in it. TDA2540, TDA2541). Mark Zenier Washington State resident |
#19
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dxAce wrote:
You're a 'newbie'... right? LOL! If you only knew... RK |
#20
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rkhalona wrote: dxAce wrote: You're a 'newbie'... right? LOL! If you only knew... So tell me, tell us... No need to be a poseur. dxAce Michigan USA |
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