Friday, January 18, 2013

Hickok Tube Testers

I have two Hickok tube testers, a Cardmatic model 123A, which has been my old standby since 1980, and a Model 6000, which I've never used (because I have the Cardmatic, which is cooler).

Unfortunately, my 123A has several problems.  It has a horrible AC leakage problem, I get around this by connecting it to a GFCI strip and not connecting the ground.  If I forget it's leaky and touch any  metal part, the GFCI triggers instantly.

I should get that fixed...

But right now the problem is that it stinks.  It has some kind of mold problem, or cat spray, or dead rat inside, or something.  I've moved it to my new very well sealed and climate controlled storage building, and I was able to keep it from stinking up the place by putting a blanket over it.  But eventually the blanket will pick up the smell, and then....

Girlfriend immediately says "get rid of it."  I try to explain how important a piece of gear this is.   I say "in top shape it would be worth $1000 or more."  Unfortunately, in the shape mine is in now, it might not be worth much for sale.

But arguably I might do fine by selling the 123A as-is on ebay and just using the 6000.  I bought the 6000, in fact, as a backup unit.


Sunday, December 30, 2012

Adapter required for Euro L-1000T

The European Kenwood L-1000T (and I get the feeling that most of them sold in Europe, as FM was out-of-fashion when the fantastic L-1000T was introduced) requires this particular adapter, or so it seems right now:

PAL Male to F-Connector (Coax) Female
Radio Shack #278-261

"PAL adapter" for short.

Unfortunately, after adding a second adapter to the B input, the B input still cannot be selected.  I'm not sure if this is because I don't have the correct remote, I was thinking it would auto-select the B input if stronger, but I couldn't find any station where that happened.


Wednesday, December 26, 2012

Remote Control for FM in every room



When my 4 day Chrismas holiday began, I had only one remote for controlling my wonderful Kenwood L-1000T FM tuner, and it only worked in the living room aimed in a very tricky way at the actual L-1000T because of how it is tucked behind the speaker.  I had to reach and wave the remote until it finally worked.  I did have a learning programmable remote control that I had never gotten to work, and another brand name programmable remote still in it's packaging.  Without remote control, it's is not desireable to scan FM channels but rather simply to keep it fixed to just one favorite, which can get boring particularly over a Christmas holiday...

Now I have easy remote control of the L-1000T in the living room, and in the bedroom and kitchen as well, through my network of remote control extenders.  Remote control extenders receive a remote control infrared signal in one room, send it via radio signals to another room, and then transmit the infrared signal toward the equipment that is to be controlled.  Most of the ones I use are from Radio Shack and they are small black rounded pyramids with short antennas.

And now I also have two working remotes, one being the Sony RM-VL610 learning programmable remote that had never worked before (now I can't find the unopened one).  I've spent much time listening to different stations in bedroom and kitchen.  With just one control, it is almost always in the wrong room, but with two remote controls I can have one in kitchen and one in bedroom, so they are always there, I don't have to remember to carry it with me.

The trick was finding the instruction manual to the Sony learning remote, and successfully getting it to learn the L-1000t remote codes.  Even with the instructions, it was tricky because the instructions themselves are not very clear in parts.  It's often unclear when you simply press buttons as opposed to holding them, or vice versa, and when you are supposed to let go.  In fact, in one particular case, you are supposed to hold a button, and the manual just says "press" and not "press and hold" but if you read to the end of the section, in the Notes section it tells you that you are really supposed to "press and hold".  Actually, it works either way, most of the time, which makes things even more confusing.

Once I had programmed the remote, which I was doing in the kitchen, I found it worked through the kitchen wireless remote receiver.  And then I tested it using the bedroom, and voila, the programmable remote actually worked better in the bedroom than the actual Kenwood remote.  So I could use the Kenwood remote in the Kitchen (or living room) and the Sony in the bedroom.  I then found I could program buttons on the Sony to control the HDMI switch in the kitchen (something that I had tried but never been able to do before) and also the Samsung TV in the bedroom (another thing that I had tried but was never able to do before).  So I'm on my way toward being able to use this programmable remote to control many things, making bedroom remote control life in bed far easier.

One other thing I had to do before I made any progress was to re-orient the remote control transmitter in front of the L-1000T.  The current orientation of the L-1000T and the remote extender are shown in the photo above, the remote extender is in the lower left corner on top of a pile of collectable Allied Radio catalogs which boosts it to the correct height.  Sometime in the past few weeks I had been trying to remote control the L-1000T directly, thinking the remote extenders were not letting me get at all the obscure functions.  So I had angled the L-1000T badly for the remote transmitter so it was not working at all.  So I had to do a lot of fiddling with the angle of the Kenwood and the angle of the remote transmitter to get it to work again.  It mostly didn't work from the bedroom, but it did work from the kitchen, after much fiddling.  I tried attaching a bunch of tie slips to the antenna on the transmitter to make it work better in the bedroom, but that approach didn't help.  I was finding I could use the Kenwood remote in the bedroom so long as I as standing right next to the bedstand light in a particular spot.  As inconvenient as this was, at least it verified that the remote control extenders were working correctly.  It took using the Sony programmable remote for reliable and easy bedroom operation.  One can guess that the Sony programmable remote puts out a higher signal level than the Kenwood remote, and that makes it work better through wireless extenders.  Or, perhaps it puts out a "clarified" signal with exaggerated on/off edges, the kind of thing you get when you use a "sharpness" control on some TV's.

A learning programmable remote is absolutely required for this application.  Programmable remote controls with a bunch of presets never or almost never have settings for extremely rare components like the Kenwood L-1000T tuner.  But since preset types are much easier to use than learning types, preset remotes have mostly driven learning remotes off the shelves.



Monday, December 24, 2012

making more of the L-1000T

In the early hours of December 24, I finally hooked up the Lavry AD10 digitizer to the Behringer DEQ 2496 which applies EQ correction for my European L-1000T.  I used a Monster Standard 8 foot optical cable.  With that digital connection, I was able to bypass the inferior digitizer at the input of the Behringer itself, and therefore enjoy the benefits of the better Lavry digitizer in other rooms, when listening to the L-1000T remotely using my Sonos system.  It also allows me to select the L-1000T in the living room without having to change the EQ mode of the DCX crossover, which can also perform the EQ correction, and yet still enjoy the benefits of the Lavry front end.

The benefits of this change seemed clearly audible in other rooms, which previously could not enjoy the benefits of the Lavry at all.  In the living room, I could previously, and can still, listen straight from the Lavry into the AES input of my Tact.  When I listen that way, I have to get up and turn the EQ mode of the crossover from OFF to ON.  That setup still seems to provide the last nth degree of performance, seeming to have slightly better incredibly real 3D imaging.  But it's a pain to get up and turn the EQ mode of the crossover on and off, far simpler just to switch inputs on the Tact, where I can select the digital output of the DEQ as input.

As compared with using the digital input of the Behringer, using the Lavry provides an especially musical sound, with utterly transparent but non-electronic sounding midrange.  By comparison, the Behringer has a slightly etched sounding midrange that sounds like hifi reproduction, not real music.

It's funny how (or if) I can hear this even going through a second level of digitization in the Sonos system itself.  Sonos lets me listen to line inputs from every room having a Sonos box.  The Sonos line input must be an analog input, which is then digitized to 44.1khz by the box and transmitted through digital signals on the CAT-5 cables that connect all rooms in my house.  Each other Sonos box can pick up this signal and play it back through a digital output which gets fed into the Tact preamps in living room and bedroom, and the Yamaha HTR-5790 receiver in the Kitchen.  When listening to the L-1000T in the bedroom, for example, here is the chain of connections:

Kenwood L-1000T source, using variable output adjusted to within 3dB of Lavry dynamic range
6 ft Radio Shack RCA cable
dB systems selector switch with Teflon jacks
0.5 meter Cardas crosslink cable
unbalanced-to-balanced adapter plugs
Lavry AD10, which samples produces optical digital output at 24/96
Monster Standard 8ft optical cable
Behringer 2496 DEQ programmed to correct European 50uS to 75uS (slight treble shelving)
Balanced-to-unbalanced audio adapter plugs
6 ft Radio Shack RCA cable
Sonos 80 analog input in Living Room
CAT-5 cables and switches
Sonos 80 digital output in bedroom
Blue Jeans digital coax connector
Tact Preamp digital input
...Behringer DEQ for EQ and DCX for crossover
Parasound HCA-1500 power amp
Revel M20 monitors
SVS 1642 plus subs (connected to DCX)

Yes, it goes through all this stuff, but mostly in transparent digital.  With the Lavry at the front end, it all sounds so good you could imagine a direct analog electronic connection to the original source.  The fact that it's all going through a second level of analog-to-digital conversion in the Sonos 80 is not audibly apparent.

The Lavry and Behringer are connected at 24 bit 96 kHz digital.  When I'm listening in the living room, I can either select the Lavry directly from the Tact, or connect to the optical digital output of the Behringer--in which case the Behringer is being used in pure digital mode, with digital input from the Lavry and digital output to the Tact.

I bought the Monster Standard 8ft optical cable at Radio Shack a few weeks ago.  It has a sticker on the plastic case it came in saying "E-Z Open Package."  It was easier than some, but still a big pain.  It took a fair amount of torque to get the back plastic panel of the package to tear off, and as it was tearing off tiny pieces of plastic and paper (from the E-Z Open sticker itself!) flew off.  I had to wipe down my leather chair afterwards to brush off the specks of plastic and paper.  And then, the package still didn't open enough to remove the cable ends, which were held behind a second plastic panel.  After many attempts, I finally got the second plastic panel to tear off, removing the cable ends, and without tearing the cable apart.  Once again, this produced tiny bits of plastic flying through the air, but this time I was no where near my chair.  Then, the cable itself was held together with a soft plastic wrap that did not tear or easily unwrap.  I had to use the tiny scissors from my Swiss Army knife to gut the plastic strip without damaging the cable.

This is a HUGE contrast to what was a truly easy open plastic package, the package that my $400 list price Nordost Baldur balanced cables came in.  It did indeed snap right open, and without apparently producing tiny bits of plastic and paper,   And the inner plastic retainer panel was then held in with friction and could easily be pulled out or put back.  Once opened like this, the Nordost box was re-useable.  The cables were held together with soft re-useable velcro tape.  In contrast, the Monster box now fully pulled apart is clearly a piece of trash (having a very vague resemblance to the jaws of a shark) featuring rough edges that you never want to see again.

Aside from the considerable difference in list price, another feature of the Nordost cables is that they are made-in-the-USA.

And then nothing beats the ease of opening Cardas cables, which come in a large but very heavy duty ziplock style bag.  Also made-in-the-USA of course.

Somehow when you pay the extra bucks for a true premium made-in-USA cable, you get nice packaging as part of the deal.

One of the reasons I had been slow in making this change, was that I often like to keep the Kurzweil K2661 keyboard connected to the living room system, also through the Lavry.  If I have the keyboard selected in the living room, as I often do, I couldn't listen to the L-1000T without going into the living room and changing the selection on the dB systems selector switch.

Well I decided that it would be OK to listen to the K2661 through the less high quality line input of the Tact, which has 16 bits of resolution according to Stereophile.  Note that the balanced output of the K2661 first goes through a Jensen ISOLINK transformer to change to unbalanced.  With that connection, unfortunately, I have to turn the volume way up because the output is apparently quite a bit lower than the 1.6V max input of the Tact with most program.  I'm thinking of putting another line amplifier in between, such as the Classe CP-35 I am not currently using.

Wednesday, December 12, 2012

Test Patterns

Here is a discussion of analog and digital video resolution and links to test patterns.

The pattern I used  pattern seemed to show 525 line video resolution in 480i displayed on my Samsung 40 inch 550 series LCD monitor displayed in 16:9, using Mac Mini mini DisplayPort output through component video adapter into Sony RDR-HX900 which serves as analog video selector, then into a DVDO which converts to digital at 1080i, thence to HDMI throughout my house.

I was thinking 525 was a limit but it's actually 540.  But quite possibly 525 is more practically achievable.  Anyway, this is quite good for a 480i component video display.

I did find that reducing sharpness to zero or at least below 10 gave the best display on the Samsung.  That is what you generally find with digitally perfect images.  "Sharpness" doesn't add real resolution, it only adds artifacts which appear like resolution with a very lousy picture.

But hooked up this way, there was visible jittering in the top 1/10 of the picture.  The jittering was not very visible from a distance, but appears to make picture softer.

Wednesday, December 5, 2012

HDMI handshaking

Well I've often wondered what HDMI interfaces actually do in the seconds that it takes for them to make a new connection.   Here's a great discussion:

http://www.hdmi.org/CEDIA2011/6-QuantumData-CEDIA_Seminar_[Compatibility_Mode].pdf

Here's the book, literally, on HDCP.

Here's a little Gefen EDID echoing device for solving problems like the one I had putting video from MiniDisplayPort onto my HDMI switch. (I just now bought one.)

Here's another discussion of HDMI troubleshooting at a high technical level.




The Artifacts

The artifacts I see from the Mac->Belkin->Monoprice->Sony->DVDO hookup described in last few posts, as viewed on my Samsung, are clearly interlacing artifacts, specifically the artifact known as combing.

http://www.neuron2.net/LVG/interlacing.html

This might or might have nothing to do with the Apple and it's output, which I have suspected is far from perfect, in 480i.  But perhaps there is nothing wrong with the Apple 480i at all.

In fact, I have another bit of evidence, this combing grows and shrinks over time, perhaps a second or so.  This suggests a possible ground loop in the connection between the Sony and the DVDO.  This would not have changed with the new Mac Mini (which, like the laptop, has two prong power connection which avoids ground loops).  Maybe...it was previously there and I just never noticed it before.

That wouldn't necessarily explain the added softness I seem to sense compared with the S-Video output of my Titanium Powerbook.  Though perhaps I didn't pay enough attention to that before to compare fairly.  I do know that on still images especially the DVDO upscaling (as with most upscaling) gives a smoother, film-like quality compared to the brisk sharpness of 480i.

Though, I may have improved that a bit by adjusting the Underscan control in the Mac Display Preferences. Funny I did not see this control at first, and I was aggravated that it wasn't there.  Because it wasn't there, or I overlooked it, I spent more than an hour fiddling with the adjustments on the DVDO to no avail.  (For some reason, with 1080i output, the DVDO was not able to apply this underscan effect to compensate for the monitor overscan.  The Zoom and similar features could only expand the image, not make it smaller.  And changing from 16:9 and 4:3 didn't help either.

This puts more of the image on my TV screens (I've adjusted it now so you see everything) and thereby shrinks the image a bit, which makes it seem like better focus.

Still much room for improvement, and I still think the Powerbook display at 480i was much better.  The digital output to component that I am using now should be about 50% better still than the S-Video hookup, but it seems like the opposite.

I need to get some test patterns I can play through the Mac.