RF (Antenna) plumbing

In CATV it is called a 'Distribution Amplifer'. Here is an example of a one in, eight out remote powered DA for CATV:

I don't see a power supply with this listing, but new, sealed packages show up fairly often or you can make your own out of a wallwart and a chassis mount female F' connector.

The matching power supply is called 'ARPI-200M power inserter'.

I bought a used set for 99 cents plus shipping in July. I still need the large plastic junction box to mount it outside, and to replace some existing coax.

Good luck with those. I used to buy dead ones for 50 cents and replace the single transistor that died every time there was a nearbly lightning strike. They dropped like flies in Central Florida.

They are very easy to pry open, and quite often the back doesn't make good contact so stray RF can get into or out of the cheap stamped steel case. (Ingression or Radiation)

surplus for $1.99.

Try below 30 MHZ for standard systems. Some 'community loops' used mid split, so it was everything below about 75 MHz.

You need some 'DC Blocks' which are capacitors in the line to isolate the RF from the DC. The ones I built for Microdyne's in house use were flat to less than .1 dB from 100 KHz to 800 MHz and look very nice on the network analyzer. Some of the RF and video modules required them when being tested and we had to many variations so I built one with multiple capacitors in parallel, to improve the bandwidth. Somewhere, I should have a copy of the drawings and notes I submitted to get a test fixture number.

Or, install the injector further upstream -- closer to the amplifier (and "above" the splitter)

Cool! But, I don't see any mention of gain...?

(But even buying *15* of them would be pocket change...)

So, this addresses the splitter *and* buffers. Instead of inserting an amplifier upstream (to compensate for the insertion loss of the splitter), this gives me unity gain *across* the slit AND buffers each output (as Joerg has suggested)?

So, the only losses I have to deal with are the ~5dB in the cable "drops"?

Hacking together a small supply is never a problem.

Anything special about the box? Or, will any (suitably sized) box work?

(not a problem for my application)

OK, so roughly the same as DTV.

We don't use cable so its not an issue. I am more concerned to make sure the wiring scheme *can* accommodate CATV when/if the need arises.

Thanks!

--don

There is one TV jack. If the TV needs to be in another corner we'd just run a longer cable to it. After all, it's only for the duration of a sickness that might possibly strike some day.

Both have TV jacks. The back porch also has CAT-5 but normally unplugged for security reasons.

You must have built the house from scratch. There would be no way to get CAT-5 to all those places here.

The real AC is never on anymore because we have an evap cooler now. The time constant of that cooling is several hours, so we have a totally revolutionary control concept: Walk over there, reach over, turn big knob :-)

For some other stuff we have several handheld RF remotes.

We used to have X10 for all that, with a central controller that can be reached via any of the remotes. But the PLC part, comm standard, and the hardware are all of sub-par quality so I ripped most of it out again.

I dropped my efforts to do that. It's impossible in an existing house like this because there is no decent hardware at reasonable prices. Huge untapped market, the big players simply don't get it.

You'd probably have to sit down and rebuild a relay.

Well, yeah, one would never mount those out in the rain. Although there's cabinets if you had to. But the electrolytic in there would likely croak soon.

That's whar thems condensers were invented for :-)

One guy in this area had his roof starting to sag after that.

Beats me why many "RF designers" can't get it into their heads that the very first component in any RF amp after the coax jacks shall be a choke to ground.

In our case it's ok since they are inside and behind the preamp. But IIRC there's five transistors in each.

That's inexpensive indeed.

Different perspectives. A neighbor was bedridden for several years before just passing away. Another friend just diagnosed with ALS. I.e., it's not uncommon for people to spend considerable time "trapped" in a room.

Plus, a future owner would probably have kids and they would want media access in those rooms.

"Wire is cheap" :>

I just change the routing tables to prevent them from going anywhere.

We re-routed the HVAC supply ducts. At the time, that gave us easy access to many of the "interior" walls in the house. Birdboards give us (continued) access to one of the exterior walls. And, the "end" birdboards give us access to two of the other exterior walls.

In two places, I had to cut small holes in the ceiling to get the drop

The drops for the front porch are currently tucked up in the ceiling

We stopped using the cooler a few years ago. *I* prefer the moist air (at least during the dry part of Summer) but I only get one "vote".

But, the furnace and cooler are also controlled. I had hoped to install motorized skylights so the cooler/ACbrrr tradeoff could be dynamic and automated. But, with only that one vote... :>

Ive put reed switches on the floor to detect when the garage door is fully closed. A long-throw opto-interrupter to detect fully open. A sensor in the freezer to monitor temperature (and provisions to monitor the compressor therein -- is it running "a lot" yet failing to cool, adequately?). The same for the hot water heater (though waiting to replace it before instrumenting that control).

Other things are much easier to accommodate. E.g., the doorbell. There are "panic cords" in the bathrooms ("Help! I've fallen and I can't get up!" :> ). I also ran controls for a motorized projection screen in the living room (I consider the big TV's to be an eyesore -- much nicer if the "screen" disappeared into the ceiling).

Things like the thermostat and irrigation controller are a bit more involved because they need to operate in the absence of "supervisory control". I.e., if the automation server crashs, you don't want the house to heat up *or* cool off extraordinarily. So, (part of) the control loop has to reside in those "motes" -- not just the I/O's (as is the case for the garage door, etc.)

Again, in our case, we took advantage of the opportunity to run wire to all of those places. If we had an attic or basement, this would have been much easier.

Once you have wire in place, it becomes relatively easy to script many of these things:

for door in doors if (doorbell[door]) { announce_visitor(); locations = locate_occupants(); for l in locations route_video(l, door); }

The amplifier I have is intended to be outdoors. Presumably taking into account the fact that it rains AND the sun shines on it.

Yes but I wonder if they'd ever *notice*? This (partial) wall supports (part of) a 25' 4x12 that carries the living room ceiling. It also acts to psychologically isolate the living room from other arts of the house (by breaking sight lines). *They* obviously decided the wanted to *open* those sight lines -- without thinking about other reasons for the wall's presence! :-/

How are you combining the multiple sources at V? I'd pay some attention to dynamic range. If you have weak signals and strong signals, you may run out of it. I had a situation where I cascaded so many splitters that there wasn't enough signal. Adding an amplifier at the front end made the whole system worse cause it overloaded the front end of the less attenuated stuff. Using a distribution amplifier designed for the job and ditching most of the splitters helped a lot.

Having quality stuff everywhere helps, but I don't have any of that.

"V" is actually intended to be an antenna symbol: _ V |

There are two. Plus two CATV feeds. So, to answer your question: I'm *not* combining anything! The DTV antenna feeds a splitter that drives the drops intended for OTA reception. The FM antenna feeds a splitter that drives the drops that feed HiFi's. The CATV lines feed a splitter that ...

I'm more concerned about the way I've routed the cables and where I've decided (schematically and physically) o locate the various "components" involved. E.g., amp ahead of splitter -- instead of at the load end of a drop...

Well, I'm not breaking the bank with this (I had to buy some RG6Q F connectors is my biggest out-of-pocket) but don;t want to make any obvious mistakes. Opening up the ceiling again to fix something would be painful. OTOH, I could very easily convince myself to just

Ok, but that warrants a lot more changes and you might then throw in another wire drop. For example right now our master bedroom has no LAN. But it'll be easy to run if the need would arise.

That's what causes problems in a lot of kids these days. I am glad my parents did not allow that.

If it's a new house, yes, otherwise it can be a pain in the neck to fish it through. Fire stops are special fun.

Oh, I just hop into the basement. And while down there, I grab a nice bottle of Belgian Trappiste ale :-)

I was lucky. At frst my wife said "But I don't want an ugly monster like So-and-so has", referring to a friend who generally just kludges such stuff. So I promised her I'd do a really nice and clean install and now she loves it. I even made a winter cover that matches the wall. Beats me why the mfgs do not sell any, they are literally leaving money on the table.

Pretty impressive. Most stuff is automated here as well but it is not networked. Because I haven't found any reliable comms method that is reasonably priced. But I do not really central servers too much.

We have a Frank Lloyd Wright style house and retrofit runs are painful to impossible in most areas. You push into a ceiling and 4-5ft later ... thwock ... full impenetrable stop.

I'd do it without scripting. Plus 99.xx% of buyers are not programmers.

Ouch! That sounds like they wrecked the static integrity of their house.

I can crawl underneath ours and actually see where they are.