Re: Front End (TUNER)

Rich Grise wrote:

On Sun, 25 Mar 2007 04:04:38 +0000, Joerg wrote:

Frank Raffaeli wrote:

On Mar 24, 7:19 pm, "Phil Allison" <philalli...@xxxxxxxxxx> wrote:

"Joerg"

Phil Allison wrote:

<insulting garbage, as usual>
[lot of snip]

[more snip]

But what really miffed me was this: Placed the antenna on a mast after
re-roofing the house. So, I equipped it with a nice preamp, splitter,
postamps with eight outputs .....

[still more snip]
I presume you meant to say that the performance of most preamps would
limit linearity, and would dominate IP3, etc. over the tuner. That's
true, although I've seen some that don't ... I've designed some that
don't; maybe Joerg used a commercial model.

Well, yeah. If a lab grade receiver works just fine and the TV on the same antenna is turning into a hopeless pile of intermodulation it's pretty clear that the TV isn't up to snuff. Which didn't surprise me. I just didn't expect it to be this bad.


Did you try an attenuator? Every TV I've had had an exquisitely sensitive
front end - it's almost amazing what an ordinary $39.00 table model can pluck out of the noise. I can see how shoving the output of an antenna
preamp or distribution amp into it could overwhelm it.


That's what I ended up doing, losing a few channels :-(

Thing is, the old ones didn't need that yet were sensitive enough to recognize the noise increase when an antenna was connected. That's how it ought to be but is no more.

BTW it's the same with radios. Two classic examples: My old Becker car radio always worked. Good old dial with string and pulleys. Then I bought an Audi and it had their, ahem, high-end radio (called "Gamma"). Horrible. In half of our town all you heard was "deedle dit deeee deedle dee". The newly installed paging system, on every FM channel. Yuck.

The other was here in the office. Nice "modern" stereo fell apart every night on the AM band. A cacophony of noise. Out it went. In came ye olde tube radio from the 50's and it works just fine, night and day. Oh, Phil, you'd like this: The well-performing tube radio was made in Australia, it's an Astor BPJ. The enclosure is IMHO ugly but it sure works nicely.

--
Regards, Joerg

http://www.analogconsultants.com
.

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