I am not sure if this is the Best Forum for this. I have a Scott 340(A) receiver and a 30 foot Water Tank(I don't own the Tank). I would like to see the best way to point an Antenna, by seeing the multipath(no I can't afford a McIntosh Performance Indicator). I found a reference to hooking up a X-Y Scope to "the output from audio detector" and the other lead to "AGC gain control signal. I prefer not to make the Electronics Illustrated(Jan-72) Multipath Scope for Stereo FM if I can just use a X-Y Scope(smallish). Question is just what bandwidth is ok?Could I use one of the chinese (board scope kits on EBay?). The above Electronics Illustrated scope uses an obsolete CA3000 chip! By way of perspective, I have years of assembly/build experience(no RF) and am not an EE. Any ideas, Thank you
The scope just needs to cover from DC to audio bandwidth. 50kHz will be fine; more does no harm.
I seem to recall answering an almost identical question within the last week or so, but I can't remember if it was on this site or elsewhere. Do a search.
I seem to recall answering an almost identical question within the last week or so, but I can't remember if it was on this site or elsewhere. Do a search.
Great, that confirms my initial "guess." But I like to run ideas by someone more skilled. I will try a search as well. Thanks for your help!!
Quadrature
Yes, thanks, I was looking at this before, but I think this is for Solid State and Ham Radios? I figured I need something closer to my equipment(tube & FM). Thanks.
Yes, thanks, I was looking at this before, but I think this is for Solid State and Ham Radios? I figured I need something closer to my equipment(tube & FM). Thanks.
HAM radio amateurs (like myself) are absolutely not interested in multipath reception. Unless it extends the range. And the principle of multipath is identical for both solid- and void state technologies.
That link tells you the principles. You just have to apply them to your particular receiver. If you don't understand the principles then you probably won't understand the 'scope trace.
I see, perhaps I remembered something about it in an ARRL Handbook? While the world of RF is not my area(just haven't gotten into it), looks like "it" has found me. I'm more into audio/test equip/power supplies etc.
The ARRL Radio Amateur Handbook has a nice writeup on wave propagation. If I remember correctly it also touches on multiple paths. Which would cause fading in the received signal. This is annoying but also a fact of life. Even on a short, 8km link (2m, 70cm) to a HAM friend I experience massive fading caused by propagation differences. Multipath reception with a broadcast FM signal can introduce severe distortion in the stereo image. A multipath display will aid in adjusting the receiving antenna to optimize reception.
Multipath
I now have a greater repect for people working in RF area. It makes the audio freq. range look like simple stuff.
I now have a greater repect for people working in RF area. It makes the audio freq. range look like simple stuff.
Yes, audio is mostly simple stuff. The snag is that the valves don't know they are only supposed to amplify audio, so audio builders often need to know a bit about RF anyway.
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