Sunday, July 17, 2011

Belkin PureAV AVU 1500 pure sine wave UPS !!!

There it is, the pure sinewave power produced by the Belkin PureAV AVU 1500. Many have gotten cynical about the AC power generated by UPS's, having seen so many with horrible looking output. But in this case, the cynicism is not warranted, the Belkin generates pure sinewaves as claimed.

The above picture is driving a simulated audio AC power load. Actually it's a combination of three things totaling 0.7 amps, similar to the idle of my living room system. It's driving a Beringer DCX 2496 digital crossover, the charger for an Apple Macbook Pro (it needed some charging), and the Tektronix 465M itself which is displaying the sinewave. The scope seems to load much like a linear power supply (I'm not sure if it is though) and therefore simulates the load of a Class AB amplifier in idle. All 3 pieces of equipment are plugged into a power strip having no filtering or surge protection, which is then plugged into a single Belkin outlet from the Stage 2 digital filter bank. I have the Belkin itself plugged into another strip, and flip the switch temporarily for these tests. The UPS power kicks in seamlessly, though initially there is a bit of ripple. I also tried the State 1 High Current outlet, and it worked similarly.

Note that the Belkin actually generates balanced AC power, with out-of-polarity sinewaves on neutral and hot lines which add up to 120V RMS. That is typical and expected, sometimes considered "a feature," and similar to what you might get with an isolation transformer, though it could be undesireable with equipment having high neutral leakage (you shouldn't be using such equipment anyway). The above picture is the hot side, the neutral side looked identical on the scope for all tests. I was unable with my safety-oriented test setup to combine phases on the scope.

I couldn't scope the transfer point, but the transition to UPS power and back seemed seamless and didn't cause either the Behringer or a touchy GFCI power strip which drops on brownout to reset. I actually connected the scope input through a Tektronix 10x probe, a 1k resistor, a 1.5 amp fuse on the hot side in a convenient test box I made years ago, a GFCI power strip connected to the power strip the load equipment was tested to, then the Behringer output itself. Safety First!

Running just the digital gear, the Behringer and the Apple, and running the Tektronix scope from a real AC line, gives a slightly less pretty sinewave (because the scope load tends to smooth out the digital glitches), but similar to what you might get on ordinary unfiltered AC power driving digital gear (below).

Driving the most simple linear load at hand, an old fashioned transformer-based Tensor lamp, gave a nicer sinewave, though strangely not as nice as the top one.

Driving no load at all looked even better (unless I got these two pictures reversed). An unloaded test can often be the worst case, if the generator relies on the load to help with the smoothing. But here it does fine, perhaps the best of all.

I've actually been using an AVU 1500 on my living room system for almost a year now, taking on faith that it produces pure sinewaves as claimed. I've had no problem with it at all, even continued listening through Parasound HCA-1500A amplifier right through a blackout. (I was using the Parasound at that time and still now, I will certainly not plug my Krell into the Belkin.) But I bought two other units for Kitchen System and Computer Room, and wanted to run these tests before further deployments.

Further testing shows that under large current draw, the waveform does get worse.

That waveform was produced with 6.3 continuous amp draw, as indicated by the Belkin display. I was running scope, Behringer, and a 2507 DeLonghi heater on "min" (600w) setting.  The 6.3 amps (at 118V see below) suggests about 740W continuous nearly resistive load (dominated by the heater).
DELONGHI 2507 Portable Radiator and Heater

The above is waveform is a bit disappointing, but not a practical issue as I do not intend to plug in an equivalent Class A amplifier which is about the only thing that would draw that much continuous current.  And even the waveform above is fairly low harmonic, probably not harmful to most equipment.

The Belkin specs are a bit confusing.  They specify 1500VA and 1000W for input.  For output, they don't actually specify a wattage or VA capacity, merely 120V AC and 12.5 maximum amps, non-resistive load.  The 12.5 maximum amps must be "peak" amps, not RMS amps.  I would then guess the RMS amps maximum would be around (12.5/1.414) 8.8A (which fits nicely with 1000W) but even then probably not on a continuous basis.  So with my 740W mostly resistive load, I'm pretty close to maximum output on an actual continuous basis

When I plugged in heater and still with AC power input to the Belkin, indicated voltage already sagged to 114V as read on Belkin display.  I am using one of my usual lousy chained household circuits for all this testing, not my dedicated 20A audio power circuit, so quite a bit of sag is expected.  I checked Belkin output voltage with heater connected on the following afternoon.  When connected to AC power, the Belkin is now providing about 116V as measured by Fluke 8060A true RMS voltmeter (there is some sag in this AC powerline itself as just described).  But when I remove AC power, and run from UPS battery, the AC neutral-to-hot voltage actually rises a bit, to 118V.  So even with 740W continuous load, the Belkin UPS actually has stiffer power than my lossy AC powerline.  I bet it can't continue that much higher, at some point the UPS would shut down when the power line would keep chugging, and you can see from the deteriorating waveform that the UPS is already struggling.  It must have some sort of regulation or feedback that is keeping the voltage near optimal within its operating limits, and at 740W continuous load it pushes up against the limits of the inverter power supply, which would explain why the waveform deteriorates.  I do not intend to do destructive testing by seeing what happens when I turn heater to medium.  At best, it would shut down gracefully.  So 740W continuous is as high as I'm going to test.

Here are some real world tests on the AVU 1500 on my living room system.  This is what it looks like powering the entire system (Parasound HCA-1500A amp, SVS 1000W subwoofers, everything) with the highest continuous level of pink noise I feel comfortable with (Tact set to -10dB, source is Stereophile CD 2 with -20dB rms pink noise), plus 0.6 amps or so for the scope itself (which is actually more than the amplifiers are using continuously).  Total current shown is about 2.2 amps continuous.  Still looks very nice, nicer than lots of wall power, though you can see a bit of rounded clipping of the sine waves:

Now this is what it looks like doing the same thing with 42 inch Olevia LCD TV turned on.  Current is now shown as 3.3 amps:

Now this looks surprisingly similar to the 740W load above, even though it's not quite 400W.  Wall power is usually better than this, but not always, and I've seen worse.

Bottom line, the PureAV backup power is very pure sinewave as advertised up to 250 watts or so, and good enough for most audio uses I have with my current Class AB amplifiers, certainly good enough for keeping everything at idle.  It begins to show a bit of strain and loss of sinewave purity when big TV is running also, 400W and above, though still good enough, and even puts out a barely acceptable looking clipped sinewave at 740W with no voltage drop. 

Saturday, July 9, 2011

Blue Man Group "Complex" DVD-Audio

I love DVD-Audio recordings in general, and "Complex" is no exception, even though about 1/3 of the songs are pure dross.  The ones that have passion really do it.  Good luck finding one of these, it wasn't easy for me, and then I ended up with 2 because I started with a used copy, then finally found NOS.

This DVD-Audio has 3 modes, 5.1 DTS, 5.1 MLP, and 2 channel LPCM.  As I have my Oppo BDP-95 set to default to DVD-Audio, I get 5.1 MLP if I just insert and press enter.  Trying to select any other option is a puzzle box.

For example, to select DVD-Audio, you would think that you would press right, then up.   However, the correct sequence is right, then left.  Unfortunately, DVD-Audio's are almost always like this, each one is a unique puzzle box, especially to the dedicated 2 channel listener.  But fortunately since I've set DVD-Audio as default, all I really have to do is insert the disc and press Enter.  Play doesn't start the disc, you get an "invalid selection" icon if you try to press play.  Unfortunately DVD-Audio's usually assume you always have video turned on to see things like that.

Fortunately, there is a "Display" button on the Oppo which brings up a reassuring set of informational displays on the top and bottom of the screen.

Over on the right side, it shows the bitrate and audio selection.

Otherwise, I'd get a constantly nagging doubt that I didn't make the right audio selection.  The Denon 5900 shows channel information and some other information in the player window.

I can't even remember how I got to LPCM.

I seem to like the MLP 5.1 option best anyway.  Even though I listen in stereo only on Living Room system, the stereo outputs appear to do automatic downmixing of 5.1 content.  The stereo outputs are entirely separate from the 5.1 channel outputs...and it's much better that way.

Playing in either LPCM or DTS 5.1 sounds more harsh.  DTS 5.1 sounds particularly nasty, with what appears to be volume level compression as well, possibly a choice by the mastering engineer.  But one uncontrolled factor is that those two modes do play louder, perhaps 3dB louder, and for totally fair comparison I'd need to determine the exact level difference and compensate for it.

It generally has been my experience that the MLP choices, which usually offer the highest bitrate, sound better, despite worrisome downmixing in many cases like this one which has no dedicated 2 channel MLP mode.  Possibly I simply like a more blurred sound that may result from downmixing.  It does sound smoother, but equally if not more detailed.  It's like turning the "sharpness" control on many TV's (like by 34XBR960) to minimum.  Greater than zero "sharpness" is usually an artificial peaking which is a kind of picture distortion, though on some sets you do actually get artificial blurring below a certain setting.  You have to use a test disc to be sure.

Boy have these things gotten complicated.  And it's no wonder that DVD-Audio was never a big hit, for these.  But I try to scarf up all the DVD-Audio discs I can because they're usually great, except for the ones that only have DTS 5.1.

3 Hours Work, Now More Needed

I know it doesn't look like much, 8 holes drilled into the cover of a small Hammond box.  But that represents 3 hours of work, measuring, finding drill and bits, clearing off workbench, cleaning off full face respirator used for eye and lung protection, tapping holes, mounting, drilling pilot holes, finally drilling actual holes, filing rough edges, vacuuming, cleaning up afterwards, putting away tools.  Not counting blogging.

I drilled to the specification of 3/8 inch.  However, as I feared, some of the holes don't quite fit the isolation washer groove.  Only one of the two isolation washers is grooved, I prefer it when both are grooved because that way isolation is secure.  With groove on only one side, you need to make hole generously large to assure isolation.

One part of problem is that since I don't have or use a drill press, any slight deviation from exact trueness subtracts tiny amount from effective hole size.  I wouldn't mind having a drill press, but my garage is stuffed to the gills and doesn't have room for one now.  And I do park my nice car in there too.

I will attempt re-drilling to 3/8 + 1/32.  After doing one hole, I'll test.  Maybe it will need to be 3/8 + 1/16.  Yes, I should have done that the first time around.  But when I'm all geared to drill, after an hour of prep, I like to get on with it, and feel too dirty to mess with actual jacks.


Update: It turns out my drill bit set does not have 7/16, the next 1/16 up from 3/8.  But 7/16 bits are available.  13/32 may be somewhat rare.  This project will be resumed next weekend when I've picked up a 7/16 bit.  It will have to be compatible with my 3/8 drill.

Wednesday, July 6, 2011

Fixed Sonos input in Kitchen

The flaky one-channel-dropping problem resulted from an intermittent RCA terminated interconnect cable. It was NOT the cable from Dish to the 3-way selector.  It was the cable from selector box to Sonos box.

It was a typical cheap "throwaway" cable included with some piece of equipment I must have purchased.  I use such cables in non-critical places where the utmost fidelity need not be preserved.

I threw it in trash and replaced it with another throwaway cable for now.

My old standard for such applications was the cheapest variety of "shielded" Radio Shack intereconnect cables.  Radio Shack raised the price of those cables about 3x in the past 10 years, so I quit buying them so often.  Then they dropped the 3 foot stereo variety, then they added extra fat RCA plugs on the ends, which are clumsy and often difficult to insert in tight places.  You can still buy the famous old style cable in mono singles (rather than stereo pairs).  I just bought one pair of such 3' mono cables last week.  I think I'll get lots more, maybe do some tests first.  Belkin PureAV cables also have especially fat RCA fat and difficult to insert they are virtually useless.  I bought a bunch of those then regretted it.

Radio Shack now also pushes many different varieties of upgraded cables, but quite often Radio Shack branded upgraded cables often have plugs that are especially difficult to insert (I worry about damaging the jacks if it takes more than 5 pounds of force to insert), or cables that are especially stiff and difficult to use with lightweight equipment like a 5oz selector switchbox.  I bought a bunch of Radio Shack upgraded cables before I discovered these problems.

The nicely shielded interconnect cables from Blue Jeans come with nice Taversoe connectors (spring loaded connectors hold tight but not difficult to insert) but are especially stiff and heavy (and not cheap).

Two major objective standards for interconnect cables are shielding and capacitance.  I have meter for measuring capacitance, the old standard Radio Shack cables are OK in 6', but surprisingly the 3' variety had identical capacitance (around 220pF, IIRC, so that's <40pF/ft for the 6' cable, but <80pF/ft for the 3').  That's OK I think, though MANY cables have less capacitance (while some audiophile cables have far more).

Shielding is hard to measure, but I'd guess the cheapest Radio Shack cables have shielding that is mediocre at best.  Single very open braid, IIRC, little different from twisted pair.  But since I've never noticed noise relating to use of such cables, it's probably OK also.  Not great, but OK unless you notice hum/noise from using cable.  Virtually all hum comes either from power supplies in need of refurb, or ground loops, not the cables themselves.  I know people who used twisted pair, or even spaced wires (!) for interconnects, and swear by them as "the best".  A pair of spaced wires has virtually no shielding, in fact it's a loop antenna.

Another standard is dielectric quality, but you're not getting teflon (the best) without paying a lot, and second best polyethylene is generally only found in professional (e.g. Belden) cables or overpriced upgraded cables.  Recently I've been using mainly Blue Jeans cables for most critical audio applications, and they use polyethylene (and have multiple shields and low capacitance).

Tuesday, July 5, 2011

Sony XBR960 adjustments

The Sony 34XBR960 was the best consumer CRT television ever sold.  It has taken LCD televisions many years to catch up in color accuracy let alone black level (if they ever have).

Unlike my earlier 32XBR100 (the best consumer ntsc-only TV ever sold) , the '960 I got in 2005 was not greatly in need of ISF calibration, so I haven't done it.

Mine is still going strong.  But finally playing with my Dish box a lot over the 4th of July weekend, I noticed I had the settings for HDMI way off.

Here is an interesting thread on 34XBR960 adjustments.

Monday, July 4, 2011

YCbCr is native DVD format

As explained in this thread, YCbCr is native format to DVD (as 4:2:0).  Therefore that is usually the default default HDMI format choice for DVD player.  Some displays originated with RGB format and work better with RGB format HDMI.

With YCbCr, the menu option in Denon 2910 for "extended blacks" does nothing, since no mapping to another format is being done.  I was wondering why it seemed to do nothing.

I'm currently checking all my 3 displays with Video Essentials.  Blacker-than-black was visible on all of them.

Using HDMI for audio from video sources now

I've just about finished converting over to use HDMI for audio from video sources now.  In previous blog post, I discussed connecting bedroom TV to bedroom stereo.  Since then, I've also connected living room TV to living room system, also on the Tact Analog input 1 (in quick test, it didn't seem to need isolation transformer, I noticed also that TV is plugged into Belkin power conditioner same as audio equipment).  Then it turned out my DVD player was connected to master HDMI switch with a DVI cable.  So I used the very nice 15 foot HDMI cable I ordered with my Oppo BDP-95 to connect Denon 2910 to switch with HDMI.  I kept the DVI cable connected, and tied the HDMI to it with tie wraps, thus lessening the strain on the HDMI connector from the 5 foot drop to the floor.  I wish they had made HDMI a screw-on connector like DVI, those are more secure.

Now one source remains without audio, and that is my Sony RDR-HX900 hard drive and DVD recorder, one of the key players in my system.  It only has analog video outputs, currently the S-Video is connected to the DVDO scaler which converts to DVI.  But DVI doesn't include audio, and I was disappointed to find that the audio inputs on the scaler only work through a switch function to the audio output.

So what is needed is a DVI to HDMI converter with audio insertion.  These are amazingly hard to find.  Apparently some early models had trouble with the HDCP.  I don't need HDCP in this application, the output from my Sony HD recorder is analog and not copy protected.  All sorts of Google scanning could not find anything useful or still in stock.  Finally I searched on eBay and found what I needed, an Konig DVI to HDMI converter, catalog number KN-HDMICON30.  It is alleged to have fully working HDCP.  I could not find this unit at any US based seller, but it did turn up on Amazon in UK for a slightly lower price than what I'm getting on eBay.  But it could not be shipped to USA from Amazon in UK.  So I bought the one on eBay for the interesting price of $116.66.

More Dish Radio

Sunday night I listed to many Dish CD channels, as well as SirusXM on Dish.  For awhile I was definitely getting a rock-n-roll fix,   SiriusXM might have a better selection in various Rock and popular genres.  Downside with all SirusXM stations is that there are occasional announcements.  They don't seem as annoying as they did 8 years ago when I started listening to Sirius.  So far, Dish CD channels have been announcement-free.

Sometime before bedtime at 4:30am, I switched to Aura, which is a New Age Ambient-like mix, soft yet energetic.  Very very nice, similar to Low Mecury Groovera (one of my favorite internet stations for listening to late at night at work), but more energetic, and the sound quality seems better.

Background music is not the end-all for an audiophile, but it definitely can be helpful.  Few things make a house seem like a home so much as background music you enjoy.  And at times I've even sat down just to listen to Dish radio.

Worth remembering these channels (and maybe more):

977  CD 28 Aura
972  CD 23 Intermezzo (classical)
967  CD 18 Jazz Traditions (straight ahead Jazz)
6076 SXM  Symphony Hall (Sirius XM)

6090 last SiriuxXM channel
6002 first SiriusXM channel

981 CD 32 last CD channel
950 CD 1 first CD channel

Despite the huge numerical gap between 981 and 6002, there are just a few channels (for me) in that range, so I can browse from 950 upwards, or 6090 downwards.

If I do PIP, to keep the music going on one side, I can't tune the other side without switching audio over to that side.  I can browse the guide without interrupting music however.  And after selecting video channel to watch, I can resume listening to radio channel.

Sunday, July 3, 2011

Audio over HDMI

Since I had my Sonos network going (with occasional problems like Friday's power glitch) for several years before getting an OWLink HDMI network going, I haven't much used the HDMI's audio feature.

But this has always been a pain for several reasons.  One is that I have many possible audio sources in Kitchen, and Yamaha receiver doesn't output an analog tape out if the input is digital (such as from Dish box).  I have a small 3-way audio selector to select from receiver, Dish, or DVD player to go into the Kitchen Sonos box.  But if I am in bedroom, it's a pain to have to get out of bed and go to kitchen to change Sonos input source selection.  And worse if, as sometimes happens, a bad cable or such means I have to keep going back and forth to get problem debugged.  I think I had a bad cable problem this afternoon; after re-inserting the Dish cable into the selector box a formerly dead channel came back alive.  Or perhaps the problem is in the box itself...

In previous post I suggested boxes which can extract the audio from an HDMI signal.  But such a box isn't entirely needed, most TV's have audio output that can be connected to stereo.  (Yes, I can think of some advantages in having a separate box, but on with the story.)

So with Jazz Traditions from Dish playing, I finally had motivation to try the TV-to-stereo connection in bedroom.  That would also make showing movies and Dish in bedroom much easier.

But to be sure I wasn't introducing a ground loop, I needed to find an audio isolation transformer.  That meant digging in incredible snarled audio cable box, which took about 90 minutes.  As I pulled cables out, I re-wrapped them and used ties or size 33 rubber bands I recently purchased at Office Depot.  Until recently, I didn't have a good stash of rubber bands.  I always bought those "assorted" bags of rubber bands, which are worse than useless.  They always seem to be filled with the most useless sizes, with just a few of the right sizes.  As the right sizes get used up, you spend more and more time digging to find a useable rubber band or useable tie.  Now you see why my cable box was so disorganized.  Size 16 rubber bands look good also for heavier cables, and I got a bag of those too.

Finally I found a Radio Shack isolation transformer, which I put into service with a 6 foot Radio Shack audio cable, connecting the (Samsung 550 series) TV to my Tact analog input, removing the now unused FM tuner connection on Input 1.

I plugged in w/o attenuator first, and it was much louder than Sonos connection, so that worried me.  It doesn't say in Samsung manual what the audio output jack level is, I figured it might be 2V, and the Tact analog input only permits 1.6V (intended for old fashioned 1V sources) before clipping.  But all I could find were 3dB Harrison Labs attenuators, apparently all my 6dB attenuators are already in use.  Well 3dB would probably be enough, but to be sure I got out Fluke 86D peak holding multimeter and tried measuring.  On Jazz Traditions, the output wasn't getting much higher than 0.37V for awhile, so I tried some other Dish channels.  The loudest one seemed to be a Spanish speaking one, which hit 0.8V.

OK, so probably the output from the Samsung is 1V max, that's safe with older equipment.  But I thought it sounded better and more level matched with 3dB attenuators, so I kept them in.  From the TV, the signal goes through one 6' Radio Shack cable, an attenuator, a barrel connector, and then the cable for the Radio Shack isolation transformer.  The reduced level probably helps with the cheap isolation transformer.  It would be better with a Jensen isomax, but my only unused isomax is waiting to be used at work where my Mac Pro has already burned out an Radio Shack isolation transformer, but I figure the Jensen will be more robust.

Purist audiophiles would cringe at all of this, but I think it's adequate for satellite box or similar sources.  I thought it sounded quite good, at least as good as through Sonos which has to re-digitize analog inputs.

So I should get more 3dB and 6dB attenuators, and another Isomax.

Now I need to connect DVD player using HDMI instead of DVI, and connect living room TV to the stereo in living room in a similar way.  Then I won't have to fiddle with Sonos when watching satellite TV and DVD's.

Would be nice to split audio from HDMI

Rather than going through Sonos to listen to audio from Dish in other rooms, it would be nice to have HDMI-to-HDMI with audio output.  Because all the digital inputs for my Tact preamps in both living room and bedroom are full, it actually would be more convenient to get analog audio out, though normally I'd prefer SPDIF digital output.

Here's a nice looking unit from Octavia, a bit pricier than expected, with both analog and digital outputs, though (sigh) the digital output only supports 5.1.  The video is HDMI input to HDMI output, with proprietary equalization system (everyone has something like that).

Here's a unit from CYP with only SPDIF output, and has DVI-I output which would require simple DVD-HDMI adapter.  I first saw this one on eBay listed for $79.  But it requires adapter, and actually analog output would be better for me.

Sonos Reboot

Attempting to spread the joy of Jazz Traditions from Dish around the house through my Sonos system, I discovered that Sonos controller in living room was the only one showing on the controller there.  I figured it was the fault of the living room unit (wrong!) and rebooted that one to no effect.  Then I tried "adding" a new zone player from Mac controller (wrong!).

Finally I realized the problem was momentary power outage knocked off kitchen and bedroom players.  They must have come back up in their own universes.  So I rebooted each one by disconnecting from AC power for 30 sec, then plugging back in.  That brought them back online.  Apparently the living room unit was unaffected because it is the only one running from Belkin AVR UPS.

Physical design of notch-blend filter

A small Hammond box will have 4 pairs of RCA jacks.  The inputs and outputs will be on the ends of the top plate, most widely spaced apart.  Two pairs, slightly closer together, in the middle.

The inner pairs are control jacks for two possible blend circuits, only one will be implemented initially.  When you plug shorting plugs into one middle pair, that blend circuit is activated.  The active blend parts are strung between the "grounds" of the plugs.  All plugs are actually isolated from ground.  A separate ground lug on box portion connects to system grounding point.

To disconnect both blend circuits, shorting plugs can be removed entirely or plugged into alternate circuits.  Since neither circuit would be completed, both would be deactivated.

The plugs used with be gold plugs from Dayton audio, 091-1120.  I have tested, and unlike the claim of one reviewer, the ones in my possession are not attracted to magnet, even the tab washers.  They come with white insulating washers which feel like teflon or polyethylene for isolation.

An external blend circuit could be plugged into any middle pair, with no connection to the jack ground, for convenient testing.

Dish Network Music

I've had both Sirius and XM (with Polk player) satellite services.  When Dish Network started carrying Sirius channels, I found that Sirius sounded better on Dish than on my Jensen Sirius player.  I've heard the Dish network uses higher bitrate than the regular Sirius band, and gets Sirius channels upstream of the lossy compression used on the Sirus band.  It always sounded that way.

Tonight after hooking up HDMI player (and thereby finally liberating my Dish Network box) I've been enjoying CD18 on Dish Channel 967, "Jazz Traditions".  I love that traditional straight ahead Jazz, and it's been playing without announcers also, which makes it truly enjoyable.  I believe CD18 is a non-Sirius music channel.

I do like Dish network!  Only Dish has both FSTV and Link TV, and for that reason I would never get cable.

Remote extender to HDMI switch finally fixed

As anyone who has ever actually used the Radio Shack Remote Extenders (or any of a half dozen similar and virtually identical products) knows, they do not work across large distances as advertised in a typical home (maybe in an open field).  You are lucky to get 40 feet, 45 is very difficult if you have metal objects, computers, AV equipment, etc.

Last year I found a solution online but didn't really believe it.  You open up the receiver and you will find that the antenna isn't connected "directly".  Instead, the antenna is connected through one end of zip cord, and another end of zip cord actually connects to small circuit board inside.  The two sides of the zip cord overlap by an inch only.  I figured this was some kind of RFI fix, balun, or the like.  Possibly should be messed with.  However, what I ultimately did to get remote extender (RX) transmitter in bedroom to communicate with receiver in living room to control Sony XDR-F1HD tuner was fivefold.  First I located the receiver near another receiver which works in kitchen.  Second I took unit apart, and connected extension wire to the wire that actually connects to circuit board.  Third I ran the extension wire to removed antenna, and placed antenna very high inside void of kitchen cabinet.  Fourth I ran long zip cord carrying remote LED over doorway, around living room walls and near Sony FM tuner.  Fifth I connected zip wire at that point to LED.  Anything less than all that didn't work or didn't work consistently.  Boy did this turn out to be a big project.  Then as these things go I quit using modified Sony tuner shortly thereafter...

This year it's been important to control HDMI switch underneath kitchen table (my AV production center) from bedroom.  Actually, that's been important for at least two years, since I ran OWLink optical HDMI from kitchen into bedroom and living room so I could watch video on my Sony harddrive/DVD recorder, Dish network box, and Denon 2910).  I have other Denon DVD players in other rooms but primarily use them for SACD, DVD-Audio, and HDCD discs.  The video sources in kitchen are the "central" ones used all over house, distributed through two separate OWLink systems.  Since it's all digital, there is no loss whatever and OWLink has been rock solid (unlike 60 foot custom HDMI cables).

The HDMI switch is under kitchen table because that's where Dish box, DVDO iScan HD, HDMI switch, and Cables-R-Us HDMI 4 way distribution amplifier are.  The DVDO has the wonderful feature that it can convert analog sources to DVI-D (and then DVI can be connected to HDMI switch with adapter cable).

I thought of moving the switch to the main equipment rack where Yamaha HTR-5790, Sony RDR-HX900, Denon 2910, Sony SLV-R1000 VHS, and (yes!) Sony SL-HF900 Super Beta players are and McIntosh MR78, as well as tiny space for PlexiWriter Premium CD player used with Mac.  Problem is, if I moved the switch, I'd really have to move the distribution amp and DVDO as well, and there really isn't enough room in that rack, a Middle Atlantic 3' unit with the two videotape recorders piled on top.  The unit is already so jammed with stuff I worry about the Middle Atlantic rack, made mainly out of particle board, collapsing (most likely not straight down because of the metal rack rails, but to one side, going from rectangle to parallelogram) with more than 100 pounds of weight on it, about half piled on top.  And did I mention the equipment rack and everything sits atop a 2' authentic antique Coats & Clark spool cabinet where I store excess remote controls, manuals, and other stuff.  I think the 150 year old spool cabinet was made plenty strong. but it makes everything seem a bit teetering.  I recently removed 40 pound Kenwood 600T from pile on top, making it seem a bit less dangerous.

Well unfortunately underneath the table it proved nearly impossible to get any kind of remote extender to work down there, no help from the low elevation and piles of equipment down there.

But recently I figured I could put small antenna on top of the equipment rack (I had spare antenna from X10 compatible multihousecode remote receiver that I quite using) and run wires down to the remote extender.  I actually set this up in ad hoc way a few weeks ago.  I had the antenna base wedged below the VHS player and sticking out horizontally (so you might bump into it if going behind rack or to that corner of kitchen).  And I connected to stock remote extender with a sucession of 5 wire test clips, which connected to the black painted antenna of the RX receiver.

That worked sometimes, but other times not.  I was getting very annoyed.

So today, July 3, I finally got around to fixing it mostly right.  I screwed antenna base right into rack as if it were another piece of rack gear (see picture above).  Then I attached RG59 coax cable, in one 6' and one 3' length down below table (now secured with AV staple and wire tie) Then I connect just one test clip lead from antenna conductor to RX receiver.  I took RX apart, and separated the two unconnected sides of the zip cord, stripped one end of each, and twisted them together.  then I put unit back together.  Just putting modified unit under table didn't work at all.  Attaching clip lead from antenna cable worked unreliably.  The best fix was removing the antenna (which has black non-conductive coating).  It took about an hour to find the correct tiny phillips screwdriver to do it.  After an hour of moving everything in my computer room around, I found it right atop the mouse table where it would have been easy to find if not buried below papers.  I had used the screwdriver recently on my glasses.  After removing the antenna, I noticed that the threads where the screw went was the only part not coated with non-conductive material.  So I attached the clip lead right there.  And it works reliably now.

To be sure I didn't catch my arm on the RG59 cable and topple the middle atlantic rack, I got F-to-pushon adapter for the cable, so that it will easily pull off from antenna.

Then after this incredible project which took about 3 hours more than it should have, I spent about 90 minutes blogging about it.