Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
Ron Hardin schrieb:
Is the 7030 any better than the R8B in suppressing a loud MW station 10 kHz away, when listening to the distant sideband of the wanted station? It should be, particularly when using the 2.something kHz (SSB) filter. The 4 kHz filter with some offset via the PBS should also work quite nicely, though. (IIRC it's a rather good Murata CFK filter, the wider ones are rather ordinary CFWs. They do, however, benefit from cascading.) The R8B gets its agc hit by the unwanted station (which is really really strong) in this situation and so makes the wanted station unlistenable. So the synch selects one sideband but the AGC reacts because the signal is still within the filter passband... kinda the problem a 7600G has in SSB when a stronger station is talking on the other sideband. I can't null the unwanted station because it lines up with the desired station exactly. A little better tails on the passband might fix it. We're talking about ripples I think, and how far down they really are. The Radio Netherlands review states a rejection of 99 dB @ 10 kHz distance for the 2.1 kHz filter, unfortunately there are no measurements for the 4 kHz in the "Plus" but the 5.4 kHz filter (which in itself is not too exciting) already obtained 65 dB. (Due to its cascaded filters and low-noise oscillator, the AR7030 excels in terms of filters, no doubt. The Drake uses coil filters at a 50 kHz IF, which are certainly quite good but probably can't keep up with that kind of performance.) Should things get really hairy, you can still manually adjust the AGC. Stephan (whose AR7030+ still needs a Decent Antenna[tm]) -- Meine Andere Seite: http://stephan.win31.de/ PC#6: i440BX, 2xCel300A, 512 MiB, 18+80 GB, ATI AGP 32 MiB, 110W This is a SCSI-inside, Legacy-plus, TCPA-free computer ![]() Reply to newsgroup only. | See home page for working e-mail address. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Passband tuning or IF shift? | Shortwave | |||
What is Passband Tuning? | Shortwave |