Thursday, December 24, 2009

MERRY CHRISTMAS EVERYONE!

Merry Christmas, Everyone!

Once again, I am posting a “blog” entry that has nothing  to do with Amateur Radio or my repeaters, other than I used to read this poem over my repeaters on Christmas Eve. This was a long time ago, when all I had on the air was .47 and when I owned 145.43 in the early eighties.  Perhaps next Christmas, I will read it again, over all of the repeaters. Lets all remember the real reason for the season.

One Solitary Life

Here is a man who was born in an obscure village, the child of a peasant woman. He grew up in an obscure village. He worked in a carpenter shop until he was thirty, and then for three years he was an itinerant teacher.

He never wrote a book. He never held an office. He never owned a home. He never had a family. He never went to college. He never travelled, except in his infancy, more than two hundred miles from the place where he was born. He never did one of the things that usually accompanies greatness. He had no credentials but himself.

While he was still a young man, the tide of popular opinion turned against him. His friends ran away. One of them denied him. He was turned over to his enemies. He went through a mockery of a trial. He was nailed upon a cross between two thieves. His executioners gambled for the only piece of property he had on earth, his seamless robe. When he was dead, he was taken down from the cross and laid in a borrowed grave through the courtesy of a friend.

Nineteen wide centuries have come and gone, and today he is the centerpiece of the human race and the leader of all human progress. I am well within the mark when I say that all the armies that ever marched, all the navies that ever were built, all the parliaments that ever sat, and all the kings that ever reigned, put together, have not affected the life of man upon this earth as powerfully as has this one solitary personality.

- Unknown

73 de Tim WB4GBI

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM  WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

Saturday, November 7, 2009

Exciting news for 146.73!!

EXCITING NEWS FOR 146.73!

 

I’m sure many of you know that I have been struggling with 146.73. I purchased the repeater from Sam (WB4HAP)’s widow, Debbie, and  after rebuilding it around a GE Mastr II unit, I took it back to its long-time home on English Mountain.  However, its performance has not been great.  The antenna was installed just above the 10 or 15 foot level on the tower, as that was the only space available.  However, I have been working with the tower owner (I rent space on the tower) and he has graciously allowed me to relocate the repeater antenna to the 130 foot level on the tower! I am purchasing a new Decibel Products DB-222 antenna for .73, and I will be installing 7/8 inch heliax to connect it back to the repeater.  This should significantly improve .73’s footprint over East Tennessee. I will let everyone know when work is completed. THANK YOU for your interest and support!

 

73 de Tim WB4GBI

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM  WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

Thursday, October 29, 2009

146.94 is 42 years young!

146.94 is 42 YEARS YOUNG!!

 

Hello, everyone! It’s been a while since my last “blog.” I hope everyone is enjoying the new 146.94 antenna. Speaking of .94, I have been on a bit of a mission lately to find out exactly when .94 went on the air. For those of you who are recent additions to our great hobby, you might not know that the 146.94 repeater was the very first two meter repeater in East Tennessee. Its history is that of great and continuous service. I am VERY proud to be carrying on the tradition started by George, K4HXD, who was the creator and founder of this repeater. We lost George in 1992. He was of my mentors. Please read the article about K4HXD on my website if you haven’t already.

 

Lately, I have been attempting to learn more about .94’s history, which started before I received my license in 1973. Thanks to conversations with great hams like Gene (W4UVR),  Charles aka “Digger”  (WA4QGX), Jerry (N4SH),  Lee (WA4QXC), Bill (WB4YPO),  Jim (WA4HQP), Bob (W4ZTV), and others, I am starting to piece together some of the history of this great repeater that I am now proud to own and operate. As of today, I have been able to determine with some accuracy that 146.94 is 42 years young this year.   The repeater started out in George’s basement in Maryville, Tennessee, before it went to its long-time home atop Chilhowee Mountain near Walland. I am told that in 1967, Ed (ex WA4GKN, now WF4H), moved to Knoxville from Nashville, and was one of the first users of .94 from his RCA tube-type dynamotor mobile as he came into the area. Note that this commercial radio, state-of-the-art in its day, was capable of only ONE channel.  Look how far we have come in just a few short years!!

 

I hope to be finding out more about .94’s storied history, and I will be adding a few details to its service record before 1985, when I was able to take over for George as .94’s owner and caretaker.  I can readily share about the post 1985 years, including a story about how my then-girlfriend, who knew very little about what she was getting into, helped me pay for the repeater. I guess that’s why I might have married her…J

 

If you or anyone you know can share anything about .94’s early years, PLEASE contact me. I would love to include your information about .94’s history as I share it with everyone.

 

What’s going on elsewhere? I’m sure you have noticed some of the problems that I have been having with 146.73. Something has been “mixing” with the repeater transmitter’s signal and appearing as a signal in the receiver input. The result is a nasty “squealing” sound similar to what happened on 145.47 when I was experiencing the problem with the high-powered UHF TV station. I hope to travel to English Mountain next week to at least install a 118.8 Hz tone board on the repeater receiver, again similar to that of 145.47. I chose 118.8 as it is an SERA- recommended tone for East Tennessee. Please note that this is NOT a permanent solution. I will be attempting to find the source of the problem and removing its capability to “mix.” This could be as easy as finding a transmitter on the mountain that has gone astray, or it could be as expensive as adding a $600 isolator to .73’s transmitter. It’s almost a two-hour trip to English Mountain, as I am a renter on a site and I must go to the office of my “landlord” and get the keys before I can access the site. I am VERY fortunate to have .73 on the site that it calls home, and these are the rules I must abide by. I am also working toward improving the antenna situation on .73, as it is low to the ground at this time. Stay tuned and please be patient as I attempt to get .73 back to the service it provided when Sam (WB4HAP, SK) and Matt (WB4IOB) placed it on the air around 1973. And if you know anything about .73’s history, I would love to hear from you as well! I do remember the great .73 picnics!

 

THANK YOU for reading. If you like what you see, please tell others. If you have a comment or even a complaint, please tell me. I can be reached via the email link on the website…www.wb4gbi.com.

 

73 de Tim WB4GBI

 

 

 

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM  WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

 

Friday, September 18, 2009

Sent from my iPod

Thursday, August 27, 2009

ITS ON THE AIR!

IT’S ON THE AIR!!

 

This afternoon, shortly after 12 noon, the new 146.94 repeater antenna was installed! Initial reports show a MAJOR improvement in .94’s signal strength and receiving capability!  From a mobile in Cleveland to a mobile in Church Hill, all reports indicate that 146.94 is back at full strength. It’s about time, huh? J

 

THANK YOU to all who helped…especially to those who contributed to the WB4GBI repeater fund. Thanks also to those who helped check the coverage this afternoon, and to Kevin, W4KEV, who helped me with checking and retuning the duplexer earlier this summer and helping me find the problem with the antenna.

 

If you get a chance, check the website (www.wb4gbi.com) and look at the pictures of the antenna installation. It’s not easy getting a 20 foot antenna up to its 250 foot above-ground home on the tower! Kerry Klimecki of Tower Services did his usual great job. I have used Kerry’s company for over 15 years for my tower needs.

 

So, for all of the nets… SKYWARN, METERS, SCRES, Blount County ARES, the Breakfast club, the Sunday Evening APRS net, and for the hams who just enjoy using the 146.94 repeater…it’s back!!

 

73 de Tim WB4GBI

 

 

 

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM  WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

Friday, August 21, 2009

IT'S HERE!!!

IT’S HERE!!!

 

After almost eight weeks of waiting, the NEW 146.94 antenna is finally here!  It arrived at my place of work yesterday.  Today, Kevin (W4KEV), Todd (KA4OAK), and I unpacked and inspected it.  There are a couple of things that I will do to it to help weatherproof it, but I will be contacting the tower climber that I use for my employer’s work, post haste, and arranging its installation!  Hang on…the long wait is almost over!

 

A couple of other things:  You may have noticed the 146.73 repeater has been off the air more than it has been on. Unfortunately, it has been plagued with some kind of interference that is causing it to lock up and pass noise. My immediate plan is to install a tone board on the receiver. The tone will be 118.8 Hz, the same as used on my other repeaters when needed. I will then be attempting to locate the cause of the “mix” that is plaguing the repeater.  I have some great plans for .73, but I can’t discuss them just yet. Stay tuned, as I try to get .73 back to its high standard of performance that was enjoyed by all when Sam (WB4HAP, now SK) had this heritage repeater on the air in recent years.  

 

Also,  I am THRILLED to announce that 145.47 has been selected to be the primary SKYWARN repeater for the district 6 area as defined by the National Weather Service.  If you are using .47 and someone breaks in and advises you that the repeater is needed for SKYWARN, please allow them to start their nets as it means sever weather is eminent.  SKYWARN is a prime example of how we as amateurs can use our hobby to provide vital communications to agencies that need our services. If you are not trained to be a SKYWARN weather observer, check out the upcoming training classes so you can help out with this important service.

 

THANK YOU all for reading my blog, and I look forward to hearing each of you on the air on one of my repeaters soon!

 

73 de Tim WB4GBI

 

 

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM  WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

Thursday, July 30, 2009

Antenna UPDATE!

ANTENNA UPDATE!

 

As I am sure you already know, I have been (impatiently) waiting for the new .94 antenna to arrive. I made a phone call this morning to the manufacturer and found out it should ship by the end of this week. Now, I am not “holding my breath,” as I have already heard this once before. The antenna has been tested on an actual test range, similar to the way radio and TV broadcast antennas are tested. I do appreciate that, as most land mobile antennas are built en masse, and probably don’t get tested individually.  I just wish the process would speed up!

 

Now, on a separate note, I need to pass along a request to those of you who read the blog, and hopefully it will get out to others as well. I am very aware that someone has been interfering with one or more of my repeaters.  It tends to happen when people are on the air and enjoying a normal QSO. I want to ask those of you who may be involved in a QSO when this deliberate QRM’ing starts to do a couple of things:

 

1)     DO NOT MENTION IT ON THE AIR.  DON’T acknowledge that the person is causing interference. If you can still hear the person whom you are in QSO with, then PLEASE carry on the conversation as though nothing is happening. I know that it is likely that you will not be able to hear the person you are chatting with, depending on how successful the jammer is in his efforts. In that case, either sign off, or move to another repeater…and make it one that you may have previously agreed to…because if you mention which machine you plan on switching to, the jammers will simply follow you.

 

2)     LISTEN ON THE REPEATER INPUT to see if you hear the interfering signal at your location. Let me or someone else know if you do hear the signal and how strong it is at your location.  If you have the means to determine which direction it is coming from, that would be especially helpful.

 

Once we determine where the offending signal is coming from, I can ASSURE  you that the offending person or persons will be prosecuted to the fullest extent of the law. If they are a licensed amateur, they will be banned from ALL of my repeaters.  And yes, that is enforceable. However, in the meantime, the more we acknowledge them, directly or indirectly, the more we feed their “jollies,” and they will continue to cause interference.  I know its hard not to do so, but PLEASE do not engage them in any way. If you have to, sign off, or move to another frequency. It’s better to do this than to engage in a “whizzing contest” with them on the air.

 

I’m sorry to have to devote a blog entry to this, but the problem is growing, and it is only going to get worse if we don’t stop letting these people know that they are getting to us.

 

As soon as I have more information on the .94 antenna, I will post it here. I am also working on some other good things for 146.73 and 53.15. Stay tuned!!

 

73 de Tim WB4GBI

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1    WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

Wednesday, June 24, 2009

ITS ON ITS WAY!

The new 146.94 repeater antenna is on its way!!

 

I am thrilled to report that I have ordered the new repeater antenna for the 146.940 repeater. I’m not sure as to exact arrival date just yet, as they are made to order.  How cool is that? I can tell you it will be a four element open dipole design, very similar to the antenna that is up there now.  I will keep everyone posted here as progress is made toward its installation.

 

I want to say a HUGE “THANK YOU” to the METERS group (of which I am proud to be a member) for their recent contributions to the “repeater fund.”  I didn’t have any idea that they were even considering this action until I received the email in which they had already voted to do so.  To say I am overwhelmed at the outpouring of support would be an understatement.  Thanks to them, the antenna installation at the 146.94 site is paid.

 

Have you noticed how quiet the 145.47 repeater is lately? No, I don’t mean activity…it has plenty of that! I mean the lack of the howling interference that was the result of the interference “mix” from the adjacent TV station.  I am planning a trip to re-install the receiver preamp now that it’s possible to have it online again!

 

Lastly, I’m sure that most of you are already aware of the situation involving the WA4BVW repeaters in North Carolina. I have met Ken several years ago and admire what he has done for VHF repeater users in his area.  His 145.190 repeater has to be the widest area coverage repeater in service in the Eastern US.  I am very pleased that the powers-that-be have agreed to allow him to keep this valuable resource to Amateur radio at its present site for at least another year. I am VERY fortunate that my employer humors my hobby and allows me to keep my repeaters at their tower sites. I also know that from the sites I don’t own or control that I am just one bad impression away from losing site location privileges at those sites.  Let us all remember to be mindful of who is listening when we are on the air. Leave the scanner listener or non-ham with a good and favorable impression of our hobby and its vast capabilities.  The next repeater site to be lost could hit much closer  to home.

 

I  hope everyone plans to participate in Field Day at some point this weekend!  And please keep the SCERS (Sevier County Emergency Radio Service) group in your thoughts…they had to abruptly cancel their field day due to some bad circumstances beyond their control.

 

I’ll see you on the air! And on an improved 146.94 repeater soon!

 

73 de Tim WB4GBI

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1    WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

Wednesday, May 27, 2009

It's official.. (repost)

Let’s try this again with a smaller font that doesn’t run together.  Sorry!  73 de Tim WB4GBI

 

 

 

 

It’s official…

 

The 146.94 repeater needs a new antenna. Kevin, W4KEV, and I visited the 146.94 site on Memorial Day Monday. Kevin fine-tuned the duplexer to near perfection. It will duplex perfectly on a 50 Ohm load, but still would not do so on the repeater antenna. Upon closer inspection with binoculars, you can see that one of the dipole elements on the DB-224 antenna is obviously damaged. The other elements may be damaged as well, but if so they are not visible from the ground. However, with this type of antenna, one damaged element is all it takes. I’m sure this is the reason for the noisy signals and “desense” that has plagued .94 for the past several weeks.

 

So now what?  It is possible to replace the one obvious defective element. However, please bear in mind that any trip up the tower by a bonded tower climber is going to be expensive. What if the repeater antenna has more damage, and we don’t find it out until after he has made one trip up the tower, only to have to make another?  This would make it even more expensive,  and .94 would still not perform as it has in the past. In addition, the repeater antenna is over 10 years old. I’m not sure of its exact age, as I brought it from another site when I installed .94 at the WIVK site in 1998. That’s at least 10 years exposure to some very nasty weather atop a 3000 ft mountain. Remember when the weather guys say things like…”more snow and ice in the higher elevations…?”   Well, .94 lives at a higher elevation. I want to do something for .94 that will last a long time and justify the total expense that will be necessary.

 

So, it’s time to replace the antenna. Too many nets and emergency communications groups depend on .94.  I will be saving sheckels and attempting to purchase an antenna in the very near future. I will have to shelve some of the other repeater’s needs that I had planned on for a while.  But I consider this a high priority. I hope to have .94 restored to its original high performance standard soon.

 

On a related note, I also spent Sunday afternoon at the 145.17 site.  I have determined that its’ interference issue is NOT the paging transmitters on site, but rather something external to the site. I hate to say this, but it acts a lot like the TV station interference I am receiving on .47 and that Todd has been plagued with on his 147.36 and 145.13. I do know that 145.17 works great on a dummy load, so that rules out a problem internal to the repeater.  There are several of us repeater owners that can’t wait to see what happens on June 13th!! That’s the day after the DTV transition, and the problematic 5 MW UHF transmitter will be in retirement. It’s also the day of the Knoxville Hamfest!! I hope to see you there!

 

I spent some time Saturday at the 147.075 site.  It was just a checkup. I sure know how to have a holiday weekend, don’t I?  J

 

73 de Tim WB4GBI

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1    WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

 

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1    WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

It's official...

It’s official…

 

The 146.94 repeater needs a new antenna. Kevin, W4KEV, and I visited the 146.94 site on Memorial Day Monday. Kevin fine-tuned the duplexer to near perfection. It will duplex perfectly on a 50 Ohm load, but still would not do so on the repeater antenna. Upon closer inspection with binoculars, you can see that one of the dipole elements on the DB-224 antenna is obviously damaged. The other elements may be damaged as well, but if so they are not visible from the ground. However, with this type of antenna, one damaged element is all it takes. I’m sure this is the reason for the noisy signals and “desense” that has plagued .94 for the past several weeks.

 

So now what?  It is possible to replace the one obvious defective element. However, please bear in mind that any trip up the tower by a bonded tower climber is going to be expensive. What if the repeater antenna has more damage, and we don’t find it out until after he has made one trip up the tower, only to have to make another?  This would make it even more expensive,  and .94 would still not perform as it has in the past. In addition, the repeater antenna is over 10 years old. I’m not sure of its exact age, as I brought it from another site when I installed .94 at the WIVK site in 1998. That’s at least 10 years exposure to some very nasty weather atop a 3000 ft mountain. Remember when the weather guys say things like…”more snow and ice in the higher elevations…?”   Well, .94 lives at a higher elevation. I want to do something for .94 that will last a long time and justify the total expense that will be necessary.

 

So, it’s time to replace the antenna. Too many nets and emergency communications groups depend on .94.  I will be saving sheckels and attempting to purchase an antenna in the very near future. I will have to shelve some of the other repeater’s needs that I had planned on for a while.  But I consider this a high priority. I hope to have .94 restored to its original high performance standard soon.

 

On a related note, I also spent Sunday afternoon at the 145.17 site.  I have determined that its’ interference issue is NOT the paging transmitters on site, but rather something external to the site. I hate to say this, but it acts a lot like the TV station interference I am receiving on .47 and that Todd has been plagued with on his 147.36 and 145.13. I do know that 145.17 works great on a dummy load, so that rules out a problem internal to the repeater.  There are several of us repeater owners that can’t wait to see what happens on June 13th!! That’s the day after the DTV transition, and the problematic 5 MW UHF transmitter will be in retirement. It’s also the day of the Knoxville Hamfest!! I hope to see you there!

 

I spent some time Saturday at the 147.075 site.  It was just a checkup. I sure know how to have a holiday weekend, don’t I?  J

 

73 de Tim WB4GBI

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1    WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

Monday, May 18, 2009

 

HEY! Why is 146.94 so noisy!

 

 

I’m re-posting this one, with a little easier to read font, hopefully…

 

 

Happy Monday, everyone! If you are a regular 146.94 user, or of you catch one of the many nets called on my 146.94 repeater, you may have noticed it is a little “noisy, “ or that portables and  some mobile have trouble getting in to the repeater. It’s not the fault of the noisy stations. Here’s what’s happening:

 

The basic function of a repeater is to be able to receive and transmit signals at the same time without degradation. One of the performance functions that repeater operators check is that of receiver desensitization, or “desense” as we call it. “Desense” happens when the repeater transmitter masks the input sensitivity of the repeater receiver. This can be caused either directly or indirecty, but it is usually a direct effect. Most repeaters employ a duplexer to allow the repeater to function properly, i.e., to transmit and receive at the same time and filter the transmit and receive frequencies from interfering with each other. A duplexer usually consists of either four or six tuned cavities, tuned to “pass” the desired frequency, and “notch” (filter out) the frequency(s) that are undesired. It is possible to operate a repeater without a duplexer, but it is very difficult on two meters to keep two signals that are only 600 Khz apart from affecting each other in a duplex situation.  

 

The 146.94 repeater has a six-cavity “pass-reject” duplexer, built by Phelps-Dodge in the 1980’s. At the time of its manufacture, it was most likely the best duplexer made. I have owned four of them, three are still in service (146.94, 147.075, and 145.47). I also have a similar Phelps-Dodge duplexer  on 444.3. Recently, I had noticed .94 being a little more “noisy” than usual. On a recent repeater maintenance trip, I decided to check the .94 duplexer. While attempting to “touch up” the duplexer tuning, I discovered that one of the transmit filters had “locked up” and would not tune! I called Kevin, W4KEV, who has the preferred test equipment and knowledge to see if he could help. I took the duplexer to his home, taking .94 off the air for the first time in YEARS. Kevin tried to “free up” the tuning shaft of the affected cavity to no avail. However, he did loan me a Wacom pass/notch cavity to substitute for the bad one, and I returned .94 to service the same night (at 3 AM to be exact).  Still, while .94 is on the air, the substitute cavity is not matched to the others, and .94 still has a considerable amount of “desense.” In addition, Kevin found another cavity that did not want to tune.

 

In the meantime, Kevin has been working on the defective cavity with success! He has replaced the tuning rod after getting the old one removed. He also has the parts necessary to repair the one still in service with the rest of the duplexer, but in order for this to happen, 146.94 will need to go OFF THE AIR. I will be working with the METERS group and other net controls to make sure that this scheduled “downtime” affects as little of .94’s activities as possible. If you or your net is affected by this temporary “off-air” situation, you are more than welcome to use one of my other repeaters until .94 is back on the air. The repair/retuning process may take a couple of days. I hope this works and restores .94 to its original great performance standard! If the duplexer continues to struggle, Kevin and I have agreed that the next step will be to replace it. That is not a cheap proposition. I have been shopping for duplexers that would be suitable for .94’s needs. A suitable replacement would need to be a six-cavity duplexer, due to the fact that .94 is in a very high RF environment. After all, it lives in the same room as WIVK’s 40 kilowatt transmitter! Plus, there are many other two-way and broadcast transmitters at this site. I want to make sure that .94 is not affected by their normal operation. Even with discounts, I am still looking at over $1600 for a new duplexer. Operating repeaters is not cheap, and I recently spent $1700 for a duplexer for 146.73. So, say a prayer that Kevin’s efforts will succeed and 146.94 will return to its pervious high standard of service. I’ll keep everyone apprised of our progress.  Thank you for reading, and PLEASE thank Kevin when you talk to him for his efforts!

 

73 de Tim WB4GBI

 

 

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1    WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

Hey! Why is 146.94 so noisy?

HEY! Why is 146.94 so noisy?

 

Happy Monday, everyone! If you are a regular 146.94 user, or of you catch one of the many nets called on my 146.94 repeater, you may have noticed it is a little “noisy, “ or that portables and  some mobile have trouble getting in to the repeater. It’s not the fault of the noisy stations. Here’s what’s happening:

 

The basic function of a repeater is to be able to receive and transmit signals at the same time without degradation. One of the performance functions that repeater operators check is that of receiver desensitization, or “desense” as we call it. “Desense” happens when the repeater transmitter masks the input sensitivity of the repeater receiver. This can be caused either directly or indirecty, but it is usually a direct effect. Most repeaters employ a duplexer to allow the repeater to function properly, i.e., to transmit and receive at the same time and filter the transmit and receive frequencies from interfering with each other. A duplexer usually consists of either four or six tuned cavities, tuned to “pass” the desired frequency, and “notch” (filter out) the frequency(s) that are undesired. It is possible to operate a repeater without a duplexer, but it is very difficult on two meters to keep two signals that are only 600 Khz apart from affecting each other in a duplex situation.  

 

The 146.94 repeater has a six-cavity “pass-reject” duplexer, built by Phelps-Dodge in the 1980’s. At the time of its manufacture, it was most likely the best duplexer made. I have owned four of them, three are still in service (146.94, 147.075, and 145.47). I also have a similar Phelps-Dodge duplexer  on 444.3. Recently, I had noticed .94 being a little more “noisy” than usual. On a recent repeater maintenance trip, I decided to check the .94 duplexer. While attempting to “touch up” the duplexer tuning, I discovered that one of the transmit filters had “locked up” and would not tune! I called Kevin, W4KEV, who has the preferred test equipment and knowledge to see if he could help. I took the duplexer to his home, taking .94 off the air for the first time in YEARS. Kevin tried to “free up” the tuning shaft of the affected cavity to no avail. However, he did loan me a Wacom pass/notch cavity to substitute for the bad one, and I returned .94 to service the same night (at 3 AM to be exact).  Still, while .94 is on the air, the substitute cavity is not matched to the others, and .94 still has a considerable amount of “desense.” In addition, Kevin found another cavity that did not want to tune.

 

In the meantime, Kevin has been working on the defective cavity with success! He has replaced the tuning rod after getting the old one removed. He also has the parts necessary to repair the one still in service with the rest of the duplexer, but in order for this to happen, 146.94 will need to go OFF THE AIR. I will be working with the METERS group and other net controls to make sure that this scheduled “downtime” affects as little of .94’s activities as possible. If you or your net is affected by this temporary “off-air” situation, you are more than welcome to use one of my other repeaters until .94 is back on the air. The repair/retuning process may take a couple of days. I hope this works and restores .94 to its original great performance standard! If the duplexer continues to struggle, Kevin and I have agreed that the next step will be to replace it. That is not a cheap proposition. I have been shopping for duplexers that would be suitable for .94’s needs. A suitable replacement would need to be a six-cavity duplexer, due to the fact that .94 is in a very high RF environment. After all, it lives in the same room as WIVK’s 40 kilowatt transmitter! Plus, there are many other two-way and broadcast transmitters at this site. I want to make sure that .94 is not affected by their normal operation. Even with discounts, I am still looking at over $1600 for a new duplexer. Operating repeaters is not cheap, and I recently spent $1700 for a duplexer for 146.73. So, say a prayer that Kevin’s efforts will succeed and 146.94 will return to its pervious high standard of service. I’ll keep everyone apprised of our progress.  Thank you for reading, and PLEASE thank Kevin when you talk to him for his efforts!

 

73 de Tim WB4GBI

 

 

 

Tim Berry WB4GBI  (check out my website at www.wb4gbi.com)

Chief Engineer

Citadel Broadcasting of Knoxville, TN

WIVK-FM/HD1    WNOX-FM   WNML AM/FM  WNRX-FM  WOKI-FM

 

Chief Engineer

Vol Radio Network

IMG College Sports

University of Tennessee

 

"Do you really want to know what's wrong...or do you just want me to fix it?

 

 

Tuesday, April 21, 2009

What have you done for me lately? V II

What have you done for me lately?

(Chapter 2)

 

Last year, I wrote a blog entry called “what have you done for me lately?” that detailed a few things going on with the repeaters. So as to keep everyone up with some “new” information, here is another installment, with info for each of my repeaters. Questions are welcome (that means someone is actually reading this!).

 

53.15: The WB4GBI six meter repeater is tuned and ready to go at my home QTH.  I have two side mounted antennae that I acquired at the same time I got the repeater from WB4HAP’s estate.  My present plan is to mount the antenna array at the 146.625 site (I think the owner will let me J ) and place the repeater on the air from there. However, the tower work will be an expen$e to be budgeted.  However, I may have a SUPER location for 53.15 that will take precedence over the .625 site!! Stay tuned and I will let everyone know as soon as I can.

 

145.17: repeater is in good shape. Last maintenance issue was the intermittent audio problem back last summer. More recently, I have signed a three-year agreement to keep 145.17 at its View Park home for another three years. I am very grateful that the current tower owner has honored the agreement that I have had with previous owners so that .17 can stay there. I have had a repeater at this site since 145.47 was there in 1981.

 

145.47: repeater is sporting a borrowed PA to get it back on the air from a failure a couple of weeks ago. The old PA and another VHF Mastr II PA are in the process of being repaired so I will have some spares. Eventually, I would like to install a commercial grade aftermarket PA on this repeater to increase its reliability even more than it is now. The receiver tone is OFF.  The offending TV station will be going off in June, and I will re-activate the receiver preamp when that happens. If the TV station interference starts up again, please remember that the tone is 118.8 Hz.

 

146.625: On my last maintenance trip to fix the audio problem on .625, the kit-built ID’er died. I ordered another one from the same supplier that I bought 146.73’s ID. Unfortunately, when they sent it to me, it had “DE WB4GDI/R” programmed into it! So, I called the company and asked for a correct ID chip. That chip actually arrived yesterday.  I will try to get it to the .625 site before the “redneck net” meets on Thursday.  For its coverage, I still think 146.625 is one of my best kept secrets.  Also, a remotely-selectable decode tone of 118.8 will be added in case we have another interference problem on the next trip.

 

146.73: Last week, I had a meeting with my landlord (I am renting tower space for .73) and he has offered me an antenna that, if it works out, will allow me to raise the height of the .73 antenna on his tower. I’m not sure whether the antenna will work yet; I will need to go to his place and test it. I also don’t know about its co$t yet.  Meanwhile, I am working on a surprise for 146.73 that I can’t discuss just yet. Stay tuned.

 

146.94: Last week, I repaired the time-out timer on the .94 repeater. It needed new capacitors. The timer is a resistance/capacitance circuit that won’t function when the capacitors are “dried up.”  The timers now work properly.  Not only is it an FCC requirement, but the time-out timers will help remind everyone to keep their transmissions short.  I have had some reports about intermittent noise problems with .94. I’m not quite sure what’s going on with this problem, but I’ll be watching it over the next little while. Also, a new remote control system is here and will be added in the next few days.

 

147.075:  This repeater is doing well with its Motorola “micor” PA that was (re)installed last fall after the Quintron commercial-grade transmitter failed for the third time. In its original life, the Quintron was a VHF paging transmitter. They are normally very reliable under continuous duty conditions, but this one had failed three times. I had spent more money on it than it was worth, so I returned 147.075 to its original compliment of micor exciter and PA. I also replaced the older remote control receiver with a newer Motorola “spectra-tac” receiver. It is basically a “micor” series receiver as well, with its original use as a satellite receiver in a voted receiver system.  If you happen to “kerchunk” the repeater late at night, don’t be surprised if my controller asks… “Why are you up?”  The smart aleck repeater controller programmer strikes! J  The autopatch is up and ready for use…PLEASE ID ON AND OFF WHEN YOU USE THE AUTOPATCH.  Your call will be terminated if you do not.

 

224.34: This repeater is doing well at its new home on Sharp’s ridge. I removed it from the 146.625 site after something kept keying it up. When I brought it home for repairs, I discovered that the errant signal wasn’t bothering it at my home. A trip back to the mountain confirmed that the problem was indeed still there. Kevin, W4KEV, generously allowed me to locate the repeater at his site, which had an existing 220 MHz antenna.  You can hear the result…the repeater did not suffer the problem that it had at the .625 site.  I do think the transmit deviation is a little high, so I will be checking it soon.

 

444.300: This repeater also got a “re-capping” in the timer circuits.  In the not-to-distant future, I hope to add a receiver preselector/preamp to the  repeater receiver.  Other repeater expenses have taken precedence over this addition for the moment.  The soon-to-be added remote control system for 146.94 will also control this repeater, as they are located beside each other at the repeater site.

 

 

A general note for all of the repeaters: As I can afford to do so, I am adding tone decoders to the repeaters, particularly the GE units. ALL of my repeaters will be set to decode 118.8 Hz when this project is completed.  

 

Lastly, I would like to say a very special “THANK YOU” to those who have recently contributed to the “WB4GBI repeater fund.”  Thanks to you, I have been able to get spare PA’s repaired for the GE repeaters, replace and upgrade my necessary remote controls, and pay the recurring bills!  THANK YOU!

 

73 de Tim WB4GBI