Posts Tagged ‘Harris’

Fixin’ Things: Week’s Update

Figured I would try and and get back into the swing of things and update a bit more often.  Mostly boring stuff, but, hey, someone has to do it! This week I have a bit of F.O.R.D. action to mention along with plans to  repair a Nautel NV20.  Also a little fun with NexGen and Sage communications.  A little bit of everything.

F.O.R.D. = Fix Or Repair Daily.  Harris Z10.  This box just sits there and is used on occasion when I do a Nautel update.  As it sits, it fails.  No, it doesn’t need to be turned on, it just fails.  I should clarify, it shows Faults.  Currently 4 when I look at the logs, used to be 5.  Let me remind you, it gets these just sitting idle.  Apparently 2 of the 4, was 3 of 5, are PA modules showing the PS#_OT, or over temperature fault.  Again, it isn’t running.  A little research and some interaction with tech support a couple months ago, I finally ordered the parts through Mouser and did a test repair.  This repair entails the replacement of a capacitor and thermistor.  Easy enough except they are surface mount, so I finally got a chance to experience this type of repair first hand.  All I can say is it takes patience.  Needless to say, the test PA module installed and fault is cleared.  I have 2 more to do.  The other faults I will act on when I get these obvious ones out of the way.  Unfortunately it looks like one of these pending faults corresponds to a dead PA.

But, wait, did I say a Nautel repair is imminent?  Yeah, I guess I pushed the old beast a bit too hard as I prepare for an HD carrier increase.  I began to adjust the HD PA voltage to accommodate the new power increase and two PA modules said they did not like that, and Poof!  I just finished doing some research and I have all the parts to replace them.  I even have the tools!  What did I find out today?  I have version A of the modules and all the latest documents show they are up to C, and they look more modular!  The old ones require de-soldering and then replacement.  At least it doesn’t look to bad.  I also get to perform the modifications that the modules required a few years back to improve efficiency.  All in all, I call this fun.

We us IP to control most everything these days, and this includes how the RCS NexGen communicates with the Sage Endec.  Sure enough, this week I noticed that the RWT did not fire properly.  This is normally caused by the old architecture of NexGen where it just decides to not talk.  After a couple of tests I had to do the old CTRL+Alt+Shift+F4 on the A-server so it would load a fresh database.  Why it decided to start doing this is beyond me.  The other two stations do not have this issue.  I know we will be moving off this system some day, so whatever we use better be IP savvy in running all tests and alerts.

Interspersed among all this fun is Microsoft and Windows 10.  Thanks.  Apparently there is an issue with Win 10 and USB 3.0.  At least with some of our stuff, more specifically Digigram and the UAX-220v2.  Thought he device uses generic Windows drivers, the system will throw a fault and reboot spontaneously.  When trying to track it down, the Event Logs show nothing except the “previous shutdown was unexpected” error.  I finally caught a memory dump and analysed it.  A reference to a USB device was there.  As a test I removed the UAX and that machine has settled down.  I think I will need to experiment with a couple of other USB sound devices and see if it is isolated to Digigram or it is more universal issue.  Sad if it is the UAX as the beauty of it was plug and play with no special drivers.

If you get a long weekend, enjoy!  If not, take advantage of the time you have!



Engineering Week Successes

Motivation has been lacking.  Been waiting a while for the sale to go through, so now we are a new company.  Very cool and it looks to be quite fruitful with the resources that appear to be had.  Many little/minor repairs have been done since my last post.  If you read the trades much in terms of streaming and connected media.  While all that goes on there is still radio and still needs to be met.  As a broadcast engineer the main deed is to keep our stations on the air!

Granted I had no off air time this week, I did have to deal with a couple of issues.  One is an auxiliary exciter that decided not to produce power.  This bad boy is an old Harris Superciter.  I believe it to be a post-Digit exciter and dates back to 2006.  As I had a spare Digit I was able to bring the Superciter to the shop for work.  Acquiring the schematics and manual was fun, and I dug up a schematic set, but no manual.  GatesAir was able to forward me a manual and another set of schematics.  After poking around I got frustrated as I did not know what readings I needed to see as certain points to determine what direction to go.  A few more emails and a better understanding led me to testing each stage.  Eventually I got really curious, so when I got to the Power Amp (PA), I began static testing the transistors which began to look good.  As this exciter is an Aux and just sits there with a quarterly turn on and run I figure it was time to really look for dirty contacts everywhere.  Anything I saw I cleaned.  I reconnected everything and had forward power!  Crossing my fingers, I put the box back together thinking it won’t turn on when I do.  Luck on my side, it came on again.  Ran it for over an hour into a load without issue.  I’ll fire it up again Monday to verify and plan on taking it back to the site.

As if this exciter thing was a pain, one of my main transmitters started doing something odd: It began having power fluctuations.  This is an “old” Nautel NV20.  Yeah, remember, I have the oldest ones out there at 6 1/2 years old now, so I get to experience the aging process.  No faults were showing except for PA module foldbacks and, sitting down, “Module # not responding.”  If a PA module is not responding there must be some fault somewhere.  I looked at everything.  I ran it into the load and watched it.  It didn’t matter which module it just randomly picked on as not responding, or two, three….  What else can I do?

I did what anyone would do.  Shut it down.  Remove each PA module and reset it.  While I did that I also checked the fans on each, though not showing failures, I’ve had a couple fail from old age already.  Found 2 that showed signs of failing and replaced them.  I check the connections to the exciter.  All good and tight.  Flipped the disconnect back on and let the AUI boot up.  I took it slow and selected a low power preset.  I stepped to to a low power with HD preset.  I went for the gold to full TPO of 10 kW.  I watched it with eagle eyes.  I dared it to do something.  Rock solid.  Heated that room up good running it into the load for 20+ minutes.  Time to put it back on the air, and it came right up.  Again I eyed it.  Both via front monitor AUI and via remote web browser, one on the main screen and the other on the status screen just waiting for it to mess up.  Rock solid.  Absolutely no power wavering.  I watched that thing for an hour, and then called it good.  The conclusion:  Even 20 kW Linux computers need to be rebooted, from a cold boot, on occasion.

Hope all your repairs turn out to be as simple and successful as mine have.  Look for the signposts while troubleshooting and take the proper path.  The repair becomes easy.  (Oooh, a Zen moment there.)


Categories: Equipment Tags: , , , ,

Carrier Drift & Diversity Delay

March 7, 2014 2 comments

Earlier this week, Tuesday to be exact, I noticed something not quite right with my diversity delay.  HD radio has added a little more complexity to our systems which requires delaying analog audio to match digital audio so when a radio switches between analog and HD audio there is no skipping or jumping.  This makes the transitions smoother in high multipath areas and only sounds like a quality change if the delay is set properly.  Knowing I had an issue I began  to look into it  when I received a call from our third-party frequency observer.  Our carrier frequency was off by -780 Hz.  Though within the legal limits, this was a large difference than the month prior.  What changed?

The technology for running IBOC, In Band On Channel, digital radio brought along some new challenges and some more things to monitor and look at.  In this case we have two things occurring:  Diversity delay drifting and a carrier off frequency.  With the new technology a source clock is required to maintain sync among all facets of transmission, and this is a 10 MHz reference.  All normal installations have a GPS signal fed to the Exporter which has a built-in receiver.  This produces the reference 10 MHz clock.  All normal installation uses this clock through the Exporter to sync their exciters, so the exciter is now synced to the same 10 MHz reference.  Most of the time this works.  In our case, on one station, it does not.  All four stations have Exporters located at the studios, and three of the four have no issues with the exciters syncing.  The third seemed to have some issues with this, so a 10 MHz GPS reference was installed at the transmitter site to clock the exciter directly.  This was my starting point.

It was safe to conclude that there was an issue, somewhere, with regard to the reference clocking since both diversity delay and carrier frequency were affected.  It was time to check things out at the site.  The ESE-110 GPS reference front panel display showed 2 green LEDs.  GPS lock and power.  Good sign.  The Flexstar exciter showed no errors.  Green LEDs and diagnostic screens showed good things.  I placed a spectrum analyzer on the 10 MHz output of the ESE.  I measured 10 MHz.  Actually it was slightly lower, like 10 Hz, but then again it is an older spectrum analyzer and probably needs calibration.  I used a TFT 844 to measure the frequency shift in conjunction with the spectrum analyzer.  Yup, it was there.  Since I wanted a third party measurement to confirm, I called him up.  I switched to the internal clock of the Flexstar.  Frequency changed and swung to +110 Hz.  Better.  The diversity delay settled down, too.  What was up with the 10 MHz input?

If the ESE output was within spec, and a call to ESE verified this along with the only indicators, the green LEDs, then what is up with the exciter?  Again, the exciter seemed to be good with the external reference according to the indicators on it along with the diagnostic screens.  I did not find the schematic at the site, another long story, so all I had was the operations manual and block diagrams.  I remeasured the 10 MHz signal.  I stretched out the bandwidth to look at the “hump.”   All the manual says is a max of 10 dBm, 0 dBm nominal, and it is used for carrier sync purposes.  They better modify that to say it is for ALL frequency references!  Mental note on  that.  I’ve been running this configuration for a year without issue, so what changed?  I stood there staring at the simplified block diagram of the Modulation Chain.  That PLL feeds the FPGA and D/A module.  Two different mixers.  Both having issues.  I read the short paragraph on the PLL.  The 10 MHz reference input is first amplified and put through an AGC loop for level stability.  I lacked stability.

My what if moment came at this point.  I have had zero, none, nada, problems for a year with my current configuration and a fairly sudden change occurred.  If they are amplifying the reference input, what if the amplifier has gone bad in some way.  I dug through the spectrum analyzer bag knowing I had a couple of in-line BNC pads.  I took out the -20 dBm pad, slapped it on the output of the ESE box, and reconnected it to the Flexstar exciter.  I gave it about 10 minutes, though I didn’t have to, and took a diversity delay measurement.  Yup, had to change it, so it was time to dial it in and see if it stays.  I got the delay down to a very respectable -0.0008 s.  At that value I should surely see a change if my solution did not work.  I gave it about 2 minutes and rechecked.  -0.0004 s.  I gave it 10 minutes more; -0.0005 s.  Before it was changing rapidly, now it seems to be locked in.  I gave a call to Harris.  While talking with support, I checked again, -0.0003 s.  OMG, this may be working.  I emailed my third party to take a measurement while I was busy talking with Harris.  No immediate response, but I was not too concerned.  The Harris tech was actually surprised at this solution, and after our talk concluded that a new PLL on site would be prudent as all indications now pointed to that as the culprit.

I packed up and blessed the site.  I returned to the station and took another reading.  The first in about an hour.  If it was drifting now, it would show it.  -0.0005 s.  I was beside myself at this point. What did I stumble upon?  It has never been this stable.  Before leaving for the day and my tax appointment, I took another reading:  -0.0009 s.  So far so good.  After my appointment, we were out eating dinner (yes, we owe the government a couple of bucks) I received an email from my contact.  He listed the times of measurements and the error, the last entry was “6:47 PM.   0 Hz error ** Wow!  What did you do?” My solution was holding!  I came into work this morning, and I checked my delay again:  -0.0004 s.

I now have a PLL module on order with Harris as we have no idea how long this one will last.  From what I can figure the amplifier section of the PLL has an issue.  The 10 MHz reference was getting distorted and creating  a new frequency that offset the carrier frequency.  In addition, the distorted signal was “outside” the specification for the unit to lock the diversity delay which was free-running allowing it to drift over a half second.  Talking with a colleague we both concluded they may want to install a test point or provide a software controlled pad on the external 10 MHz input.  For now, the problem is solved.  I am tempted to see how long this lasts or if there will be further deterioration causing drift once again.  Happy troubleshoot!



Travels, Work, and More Work

Wow, it seems to be forever since I posted.  Forgive that.  I bet you expect juicy details on super secret stuff.  Well, not exactly.  Recently I did travel, and since being back I have been busy.  Shoot, I was busy before the travel.  Does work get in the way of vacation or does vacation get in the way of work?  Will we ever know?

Vacation was great.  Part of that was to visit the Elenos factory in Italy.  I enjoyed meeting the crew out there and talking shop.  What I saw was quite impressive and the dedication and passion behind the product is amazing.  With that we may see Elenos become a player in the transmitter market, so stay tuned.  From what I understand I may be receiving one to test.  Did I mention they did win a Cool Stuff award at NAB this year?

Of course I get back from vacation, IT Dude goes on vacation.  This always equals some trouble.  In this case it is Marketron vs. Windows 7 and a Ricoh printer.  After a whole week, we still cannot print from the new machines.  They print locally, but not through Marketron.  I think I am overlooking something that IT Dude will notice right off.  That is the true difference of dealing with something day-to-day versus only on occasion.

Do I dare mention the Harris Flexstar?  I should write a whole post on just this.  Yes, I continue to have Exciter muting issues, though not as bad as before.  To make a long story short, we know for a fact that the Flexstar cannot handle too much data.  It bogs down and eventually chokes.  The only way to recover from the mute is to reboot.  I wired up my remote control to the Flexstar restart input.  This is pin 13 on the Remote User Interface of the Flexstar itself.  A contact to ground and the Flexstar will perform and cold boot.

I have been fine tuning my Burk ARC Plus installation and utilizing the AutoPilot program a bit more.  Now if we can only get Burk to support SNMP within the ARC Plus removing the need for AutoPilot they may be on to something.  In the meantime I have created a fine custom view that shows the basics of all my transmitter sites.  Attached to the touch screen monitor, all it takes is a touch of the screen to execute a function like STL switching or rebooting the Flexstar exciter.  In addition I am utilizing SNMP with my Eaton-Powerware UPS’s by adding a network management card to the UPS.  Currently four are up and running and I monitor on AutoPilot input and output voltage, UPS load, time remaining, and battery charge level.  As I learn more about SNMP I may have status notifications if a self test fails or whatever else I can find!

Maybe my next post will get into some dirty details.  If there is a subject you wish to see covered, drop me a line.


Categories: Equipment, Management Tags: , , ,

NAB Observations

Back from the NAB convention. It is always great to see people and see what is going on. Here are four observations from a list of many. What did you see, hear, or ignored?

1.  Radio was slow. Lots of elbow room on the floor. No real “wow” factor items on the floor. I did see stuff to improve the plant, but with no money one can only wish. Seems once the subject of money came up no one wanted to deal with you. That is a shame as I am always looking to integrate items into capital projects.

2.  Manufacturers selling analog only transmitters. I found it quite interesting the number of smaller market folks were looking at transmitters. They were not looking at HD, either. This was quite evident at the Nautel booth where they were showing the NV LT, an analog only version of the NV transmitter. I even stopped by and saw John Bisset at the Elenos Booth. Seems it is too expensive too license from iBiquity, both for manufacturers and end users.

3.  GoPro booth was hopping. I could not miss this Booth as it was right next to the radio section. Oh, and I have a friend that works for them. I own a Hero 2. It is fun. The buzz around their booth escalated around 3pm at their drawings. The NAB decibel police even monitored what was going on.

4.  Way cool interactive signage by Cisco and Verizon. Wandering the South Hall was interesting. We started at the upper level which seemed slow. I was looking at data delivery options, so I here’s up there. Maybe it was early, thus the lack of activity. Once downstairs we hit more crowds and happened on the Verizon booth. We talked to a Cisco Rep who showed us a great interactive display with a media player. What we saw is great for large office buildings and campuses, but we saw potential for clients. JR has medical clients so he immediately saw a unused there. Coupled with Verizon’s 4G LTE we saw potential display possibilitiiies for radio station lobbies showing live shots from remotes or a guest in studio.

I enjoyed meeting with everyone there. I can see how another day for me would have been worth it. I did not have time to talk with Orban or Omnia. Maybe next year I will take a different approach to the madness.


Categories: Equipment, Management Tags: , , , ,

NAB 2012

I have been lacking on posts this year.  Personally it has been tough with family issues culminating in the passing of my Dad.  It adds to the lack of motivation.  Now it is time to get back on track.  A kick start:  the NAB show is back!  I’ve printed some floor maps this year and I have a list of 32 vendors I want to harass, I mean talk to and look at.    All for various reasons from the obvious to the “what they He** would I want to look at them” is on that list.  What are your agenda for this year?

1.  Talk with those of which I still have some issues.  Harris is one.  Do they intend to make a new exciter that is a bit more reliable?  Am I looking at having to budget for a new Exporter that may correct some of the issues?  BTW, I received an email that specifically states that I “should have no need to move the equipment to the transmitter site,” so I hopefully am on track to eliminate or better manage my issues.

2.  Telos:  I am going to ask you point blank and face to face: Why do I have 2 Console Directors that just go to sleep and you guys cannot help with a solution?  Only two.  I am going to swap one out today with a different one just to see if the problem follows again, though I have done it before..  Gotta do though.

3.  305 Broadcast.  A new distributor on the block.  I figure I will see what they have to offer and how they compare or plan to compete with the likes of BGS and BSW.

The list goes on, but you get the gist.  I will also just wander around aimlessly because I can.  The largest road block to moving forward is money.  No budget.  I can plan and think and plan and think.  Ouch, maybe not so much thinking!

Hope to see you there!

HD Equipment Placement

Feel free to respond to this one. I should make a poll and get info that way, but I’m lazy, or not.
Where do you prefer to place your Exporter and HD equipment in general? Mine is at the studio. I have many issues with Harris, but none with Nautel. I have been asked, and I hate to admit it considering, to place the Exporter at the transmitter site. Of course they I will have to do another GPS installation, but that’s life.

Do you have any compelling feelings either way? If you would like I will post results after NAB.


Categories: Equipment Tags: , , ,
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