The 146.73 duplexer is on the air!

 

The 146.73 duplexer is on the air!!

This past Wednesday, December 3^rd, Josh McDaniel (KI4WWY) and I went to English Mountain and installed the newly acquired 146.730 duplexer on English Mountain. The power that I am able to deliver to the repeater antenna has doubled, and instead of 13 db of duplexer loss, I now have less than 2 db. What does this mean to you? It means the coverage of 146.73 has dramatically improved with this investment. This duplexer, if purchased at new list price , is over $ 3,000.  Obviously, I couldn’t and didn’t pay that, but I was able to purchase a brand new duplexer for about half that price.  I would like to say a very special THANK YOU to those who have recently contributed to the WB4GBI “repeater fund.”  Those contributions, along with some funds from Debbie Kirby, Sam’s widow, helped to allow this purchase to happen.  I hope you will check out 146.73 if you haven’t done so already.  I am also working on more improvements to 146.73’s coverage, but I can’t discuss all the details right now.  But I can assure you that you’ll be pleased.

 

The tone is still OFF on 145.47. For whatever reason, the TV interference has abated for the moment.  I’m not sure why, but let’s enjoy! Remember it should be completely gone when the DTV transition happens on February 17^th.

 

I hope to be turning my attention to the 53.15 repeater very soon. I acquired it at the same time I acquired 146.73.  It is ready to go on the air, located at my home. I am probably NOT going to be able to return it to English Mountain at this time. Remember, I am paying rent for 146.73, and also the six meter antennae take up a LOT of tower space.  But I have a surprise in the works that should give 53.15 as good as if not better coverage than it had before.  I may also be able to get it on the air from one of my other sites in the interim if necessary.

 

Here’s hoping that you and your family are enjoying the Christmas season! But let us all remember the real reason for the season.

 

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

 

 

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

 

 

O WB4GBI, where art thou?

 

O WB4GBI, Where art thou?

 

 

Well,  its been a while since I have done a “blog” entry. Heck, its been a while since I have been on the radio much. So, let you think I have fallen off the face of the earth, let me offer you a glimpse of why you don’t hear from me much during the month of November.

 

In my “other” life, I am Chief Engineer for the Vol Radio Network.  If you listen to Bob Kesling on the radio calling UT football or basketball, or Mickey Dearstone calling lady Vols home basketball games, you are hearing my handiwork. Incidentally, Dave, KE4YBZ, is almost always on the other end of our audio feed, producing the game back at our studios. As for me, I am at the stadiun or arena setting up the equipment and sending it back to Dave for distribution to our stations (WIVK and The Sports Animal) as welll as 80+ other radio statins throughout the Southeast. And this is my “second” job…I still take care of WIVK and its sister stations as their Chief Engineer.

 

If you are a UT fan, you already know this, but if not (GO VOLS!),  then I’ll try to explain our November schedule. Football is still in full swing, and Men’s and Women’s basketball is starting up. Add to that a Monday Night coache’s show on location,  a Thursday Night show (which Josh, KI4WWY produces), and a Sunday Evening show that is produced by another engineer but supervised by yours truly,  you start to have an eveny almost every night of the week.  Throw in a couple of press conferences about football coaches…and… well,  you get the picture. A wise farmer once said , “You gotta make hay while the sun shines.”  I have to make sure these broadcasts get on the air while we are in the season.

 

So, While you may not har from me as much, I’m around…I listen a whole lot more than I talk. You learn more that way J.

 

Now, what’s happening with the repeaters? Well, I have the new duplexer for 146.73 here at my house and ready to go. I was going to try to go to English Mountain this past Friday, but my daughter’s 4-runner (actually, its MY 4-runner…I’m making the payments!) needed tires and brake work, so I postphoned the repeater trip. I will try to make it up there sometime this coming week. Its about a two hour trip by the time I get the keys and head to the site. But I am sure that the time and effort is going to be worth it! If you like 146.73 now, imagine what it will be like when the receiver can “hear” what its supposed to!

 

I am also hoping to put a pre-selector and preamp on 444.300 real soon. This should help its receiver sensitivity.

 

The tone is presently OFF on 145.47.  If the TV noise comes back, I will have to turn the tone decoder back on. Please remember to set your tone encoders to 118.8 Hz. And, as a side note, if the repeater tone happens to be off, it doesn’t hurt anything to leave your rig’s tone encoder on. It just makes you ready for the times when I have to turn the one decoder back on.

 

The rest of the repeaters seem to be doing well. I am hearing a few more autopatches on 147.075 that I used to. That’s great! Please just remember to ID ON and OFF of the autopatch. I hope to have some new 147.075 pictures on the web site soon. I had to retire the Quintron transmitter that you see on the main picture…it just wasn’t stable. I went back to the old Micor exciter and used a new 100 watt PA that I acquired from WB4HAP’s estate. I put two cooling fans on it to keep the PA cooled down. ALL of the repeaters have fans on them…heat is not a friend of transmitters.

 

THANK YOU once again for  reading the blog. I’m sorry I haven’t been able to post on it much lately. And a special THANK YOU to those who recently contributed to the “WB4GBI repeater fund.” Although never solicited, these contributions helped buy the duplexer for 146.73 recently, and they help defray the regular and monthly expenses that all of the repeaters incur.

 

73 de Tim WB4GBI

 

IMPORTANT NEWS ABOUT 145.47!

IMPORTANT NEWS ABOUT 145.47!!

 

Due to a request from the 145.47 repeater group in Atlanta, I am changing the tone on 145.47 from 100.0 Hz to 118.8 Hz.  The Atlanta group had already started using 100.0 Hz, and some of my users are now keying up their 145.47 repeater since it has the same tone.  I want to be a good neighbor to my co-channel repeaters, especially since the N4CLA repeater is already using 100.0 Hz.  I will make this announcement on the net on Tuesday evening. After the net is completed, I will most likely change the tone on Wednesday. If you attempt to use the WB4GBI 145.47 repeater and you cannot access it, please change your tone encode programming from 100.0 to 118.8. Remember, as soon as the TV interference issue is resolved, I will turn the decode tone off and make 145.47 an open squelch repeater again. Please pass this information on to other .47 users.  Thank You!

 

73 de Tim WB4GBI  

 

 

 

 

Why can't I key up 145.47?

WHY CAN’T I KEY UP 145.47?

 

Have you tried to key up or talk on 145.47 and cannot?  Well, unfortunately, I have had to add a tone board to the repeater receiver. What does that mean? It means that when you transmit, you must also transmit a 100 Hz sub audible tone with your signal in order for the repeater receiver to “open up.”  Many of you understand this practice. But for those who may not be familiar with it, I’ll give a brief tutorial.

 

While not as common on amateur radio repeaters, tone squelch has been a staple of the land mobile radio world for years.  It was developed in the late fifties or early sixties. Your local police department or public safety agency’s radios have tone squelch.  They use it to insure that only their users access the repeater, and NOT other users that happen to be on the same frequency.  Like our amateur frequencies, they are shared, but unlike our amateur frequencies there are FCC sanctioned coordinating bodies to (hopefully) insure that the users of the same frequency are separated by some distance.  Land-mobile frequency coordination, unlike our volunteer coordinators (SERA), is mandatory before a license to operate is issued. Even with this frequency coordination, it is still necessary to keep users separated in these “closed” systems.  The term Tone squelch goes by several names in the commercial radio world:  Motorola calls it “private line,” GE called it “channel guard,” and RCA called it “QC (quiet channel).”  In later years, Motorola developed a digital counterpart for tone squelch that the called “digital private line” or “DPL”. Even today’s trunked radio systems use a version of tone squelch or digital tone squelch.

 

In early years of amateur repeaters, a repeater that utilized a tone squelch was considered a “closed” repeater.  Only the authorized users were given the tone frequency to access the repeater. I’m not sure what kind of honor system they were using, as the purpose of the closed repeater could be easily sidestepped if someone decided to share the tone frequency with a friend.  More recently, repeater owners have used tone squelch to mitigate co-channel users of other repeaters from accessing their repeater. Amateur repeater frequencies are also shared, meaning that a repeater in the Knoxville area can be sharing the same frequency in another area.  There are 145.47 repeaters in Nashville, Winston-Salem, and Atlanta. Tone squelch is sometimes used to keep the users of the “distant” repeater from accessing the “local” repeater, and vice versa.  It doesn’t mean that either repeater is “closed.”

 

Another use of tone squelch is interference mitigation.  That’s what I am doing with 145.47 right now. I am using the tone to keep the interference from the TV station from keeping the repeater keyed up with the loud squealing noise that I’m sure you have heard by now.  I have also had to place a tone decoder on the 146.625 earlier this year when it experienced a similar kind of continuous interference.  However, I’m happy to report that the 146.625 problem is gone now.

 

Now, here’s the caveat:  Just because you can’t hear the “other” repeater’s user(s), or the interference, it doesn’t mean the interference is gone. It is merely masked,  or muted. What does that mean?  It means that if your  signal is not strong enough to overcome the offending signal, it still won’t bring up the repeater, even if the desired signal (yours)  has the right tone. This means that if you are using a hand-held portable or your signal is weaker than the TV interference, your signal won’t make it thru the repeater.

 

It is my belief that the 145.47 repeater will not need to have the tone squelch on it for the long term.  As soon as the TV interference is mitigated, I will remove the tone from the receiver and return .47 to its normal “open squelch” state.  Certainly, it makes it easier for travelers and those who don’t have tone units on their radios to enjoy 145.47.  I have remote control of the repeater’s tone board, and have turned it off occasionally to check the repeater receiver status.   In the meantime, please understand that even if you have your tone encoder on and selected to the right frequency (100.0 Hz), you still may not be able to access the repeater as easily as you did before this TV interference problem started.  I promise you this will not be a permanent problem. The staff at the TV station and I have discussed several options to (hopefully) reduce or eliminate the offending signal that is causing the “mix.”  If you are unfamiliar with what is happening to cause the problem with 145.47, please read the prior blog entry and it will bring you up to date. 

 

What else is happening in the WB4GBI repeater world?  As you read this, the NEW duplexer for 146.73 is being tuned.  As soon as it arrives in Knoxville, I will take it to English Mountain and install it! I am convinced that 146.73 will see a drastic improvement in its coverage when the new duplexer is installed.  I will post in the blog as soon as the duplexer installed.  

 

Thanks again for reading!

 

73 de Tim WB4GBI

 

 

 

 

Get your tone encoders ready!

GET YOUR TONE ENCODER READY!!

 

 

Well, folks, as bad as I hate to do so, it appears I am going to have to place a 100 Hz tone decoder on 145.47 in order to get it back on the air.  As I am sure most of you know, I had to turn 145.47 off a week ago due to a LOUD squealing noise that was keeping the repeater keyed up. I suspected a 5 megawatt TV transmitter that is located at the same site, since the noise heard thru the repeater was TV video, also known as “ sync buzz.”  Last Thursday, I was able to confirm that suspicion when the TV stations transmitter was turned off at 5 AM for a test. 145.47 was crystal clear, and I worked a station in Lexington, North Carolina without any noise whatsoever. As soon as they turned the TV transmitter back on, back came the noise.  Several of you were up at that wee hour to help me, and I want to say thanks. But the problem came back with the return of the TV transmitter to the air…so I had to turn it back off.

 

How is this happening?  Well, here’s a little unplanned blog entry on intermodulation interference, sometimes called “intermod.”  Not all interference that is generated is “intermod,” but I will explain why this case is. When two RF signals are combined, they produce a sum (added together)  and a difference (one subtracted from the other) of the two individual frequencies. This combining, or “mix,” can happen in numerous places, from one of the two transmitter amplifiers or a rusty joint that is ripe for RF rectification. The interference that we are receiving on 145.47 is a result of a RF carrier (coming from the TV transmitter) on 290 Mhz. The 290 MHz signal is “mixing” (combining) with the output of my repeater on 145.47. There is probably a “sum” frequency that is around 435 MHz, but the problem is the “difference” frequency, which falls right on 144.87 MHz, which is, of course, the input to my repeater. When two signals combine, you will hear modulation components of BOTH signals. That’s why you hear the video noise AND the squeal. The squeal is from my repeater feeding back into itself. Think of it as the same thing as when a PA system is too loud and the output from the speakers gets back into the microphone(s) and squeals.

 

There are other ways to have intermodulation interference. Mixes can occur on a transmitters harmonic frequency. For those of you who have been around a while, you may remember when 146.625 would come up randomly and play the weather station. After thinking it was a QRM’er at first,  I decided that no QRM’er was dedicated enough to do this 24 hours per day at various intervals.  So the search began. What I found was that a paging transmitter that was being used by our local fire department had a nice second harmonic, and that harmonic was mixing with the weather service transmitter and showing up on my repeater input. Here’s the math: 154.250 X2= 308.500. 308.500 – 162.475 equals 146.025, which is dead on the 146.625 input. This is referred to as a “third order” intermodulation problem or 2 times freq A minus freq B equals freq C. There are also fifth order intermodulation products, but I have never had to deal with them.

 

So, now we know what the problem is, what can you do to fix it?  The easiest thing to do is eliminate the mix. I am working with the TV station to eliminate the 290 MHz frequency that is causing this problem. Bear in mind that this is a FIVE MILLION WATT TV transmitter. The offending frequency doesn’t have to be very strong and the TV station still be considered legal. The TV station engineer has traveled  to the transmitter site twice so far to try to find where this signal is coming from.  Today, he went with a spectrum analyzer, which is an absolute MUST when troubleshooting this kind of problem. However, he can’t “see” this signal on his analyzer. However, we know the signal exists, because several of you have confirmed it for me by listening on your receivers wherever you may be located. So, I am planning a trip to the transmitter site with *my* spectrum analyzer and a receiver capable of receiving 290 Mhz.  I fully expect to receive the signal on my receiver, and point it out to the engineering staff of the TV station. However, until they locate the signal and reduce or eliminate it, 145.47 will still have the lovely noise that you have heard until I take another course of action. That action, unfortunately, is a CTCSS (or “PL” or tone board) installed on the repeater receiver.  I had to do this recently on 146.625 until another stray video carrier finally went away. I wish I had thought to check the same source as this problem…they might have been the same thing.  

 

Now, here’s another lesson to be learned from this type of problem: When I install the tone board, the problem will not be heard anymore. Notice that I did NOT say that the problem would go away. It will merely be “muted” until a signal with the proper tone is received at the repeater. Then, if the signal (from you, the repeater user) happens to be weak enough, then you will STILL hear the video noise as it “scrubs” with the legitimate repeater user. It will affect the weaker signals the most. Some of you that were used to getting into 145.47 with low power from a distant location may find that you can’t get into the repeater, or that your signal isn’t as good as it once was. This is because the tone decoder only hides the problem of the signal that it is still on the input frequency of the repeater.  This is also one of the reasons that I do NOT like tone squelch amateur repeaters, along with other reasons. A repeater with a tone squelch is not friendly to a traveling user, unless the user happens to know the tone frequency and has the tone encode enabled on his or her radio. Most modern radios have tone encode (and decode) capability, but you have to KNOW what the tone frequency is first.

 

Lastly, what happens if the TV station can’t or won’t eliminate the interference?  There are two options. I can attempt to eliminate the “mix, “ IF (that’s a big IF) the mix is happening in the 145.47 transmitter. Unfortunately, its not always easy to determine where the mix is happening. Another problem…the device used to eliminate this problem is called an isolator.  You probably don’t have one of these laying around in your ham shack. They are around $1000 each and they are finely tuned fro the exact “pass” frequency (in my case, 145.47). If you *do* have one, I would like to talk to you J !!

 

Have you been hearing about the “Digital TV conversion?”  Well, if you have, there is some good news for this problem that relates to the changeover to digital television.  In February, ALL analog TV stations are mandated to shut down in favor of their digital signal. All of the local stations (this one included) already have their digital signals on the air. When February rolls around, guess what…this transmitter will be off the air.  HOORAY!!

 

 It is my sincere hope that I can restore 145.47 to useable service long before February.  I don’t like having one of my busiest and most active repeaters crippled, especially if its something that is not the fault of the equipment I have on the aire or a situation that I have control over. Please bear with me and I will do my very best to correct the 145.47 problem…the best way I can, as soon as I can.

 

NOW, FOR SOME GOOD NEWS! 

 

I have saved enough shekels for a new duplexer for 146.73!  I will be making the final payment on a six-cavity repeater duplexer that I have had in “lay away”  for several weeks.  I hope to have it here and tuned up within a couple of more weeks. If you think .73 is doing good now…wait until it can actually hear better!!!

 

73 de Tim WB4GBI

 

 

Why is 145.47 off the air?

 

HELP!! Why is 145.47 off the air?

 

Well,  this certainly wasn’t what I was *planning* for my next blog enrty, but I’m going to have to write it anyway.

 

As you may have noticed, I have had to turn the 145.47 repeater off the air.  Tuesday afternoon,  it started passing this horrible squealing noise.  I suspect the noise to be an “intermod hit” that involves a 5 megawatt  (that’s 5,000,000 watts) TV transmitter immediately adjacent to the building that .47 is housed in.  You can hear the video “sync buzz” when the repeater is enabled.  We have had this noise on the repeater before, but never quite this bad.  In fact, the last time we had this noise, I simply bypassed the receiver preamp and all was well again. I’m afraid that solution won’t work this time.  

 

What am I going to do about this problem?  As soon as I return from a little football trip this weekend,  I will pay a visit to the repeater site.  I will do some troubleshooting to try to determine where the “mixing” of signals is taking place. If it is in the repeater transmitter,  I will try lowering the power, checking the transmitter with a spectrum analyzer, and trying to determine where the “mix” is occurring.  I can install an isolator  on the repeater transmitter to keep RF from getting back into the transmitter PA from the outside world.  I hope this isn’t the case, as a good isolator is around $1000.  If the mix is  NOT occurring in the repeater transmitter itself, I’m afraid short of getting the offending station to cooperate, I will have to install a tone decoder on the repeater receiver. This means that you will need to encode a 100 Hz tone to access the repeater. I’m not a fan of tone squelch amateur repeaters, but it will keep the repeater on the air until the mix disappears.

 

The good news is that the transmitter that I suspect  to be causing the problem will be  off the air  after the February 29, 2009 DTV conversion.   That means that the transmitter in which the “mix” is occurring will be going away.  Wouldn’t *that* be nice?

 

On another note, I visited the 146.625 site today and tightened the noisy squelch on the repeater receiver. .625 had a similar interference problem last year.  I had to tone it up but its fine now. I tightened up the squelch adjustment, so the repeater didn’t stay on the air passing squelch noise after the user has unkeyed his transmitter.

Why not give .625 a try?

 

I will keep you posted as to the 145.47 repeater’s status.  Thanks again for reading this!

 

P.S.  I will be unable to attend the Ten-Tec hamfest this Saturday. There’s a little football game going on down in Auburn this weekend that necessitates my presence.

 

 

73 de Tim WB4GBI  

 

This and That...

 

This and that…ramblings from WB4GBI

 

Here’s hoping everyone had a great weekend.  I know several went to the Huntsville hamfest. I had planned on going, but this weekend was “move-in” weekend for on-campus UT students, which included my daughter.  I doubt she reads this, but just in case:  Paige, I am SO proud of you. You excel at anything you do. Study hard and go with God. Love, Daddy.

 

And besides, I wanted to save my shekels for a new duplexer for 146.73 instead of going to the hamfest and spending them.  So, speaking of duplexers, I have made a down payment on a set of six-cavity TX-RX duplexers. These are new in the box, but were bought for a project that was never completed.  I hope to finish paying for them in the next two or three weeks, and then have them shipped here. From that point, I will see if Kevin (W4KEV) will be kind enough to tune them up using his sweep generator.  I know for a fact that you will notice a marked improvement in 146.73’s receive capability.  I have heard a lot of people trying out .73, and I hope that those who are having a little difficulty accessing the repeater will remember that it is practically “deaf” at this point in time due to duplexer loss. I didn’t intend to put it on the air this way, but these things happen, and I’ve had to work these kinds of “bugs” out before when I have placed a new repeater on the air.  145.47 had some technical issues, believe it or not, before it became the wide-area coverage repeater that it is now.

 

So, what’s going on with the other repeaters?  Well, at this point in time, there are no major needs on any of the other machines.  I hope to add a receive preamp on 444.3 sometime soon, but its not nearly  as “deaf” as 146.73 is right now. It seems that my quietest  repeater is 146.625, for the range it has. If you find one of my other repeaters too crowded and too busy for your liking, why not try .625? It has a nice footprint and has been on the air at this location for about four years.  I have had 146.625 on the air since 1988.

 

Some of you may have noticed that I had to turn off 145.47 last night.  It was not meant as an indictment of those who were using it, but there was someone who thought it was his playtime and proceeded to key up and make miscellaneous unidentified transmissions.  I know that conventional wisdom tells us to ignore jammers and QRM-ers, and I usually try to do just that. This, however, had gone on long enough, so I turned it off for a while. The result was that when I turned it back on, the problem had disappeared, probably due to him knowing that his “playtime” was now ineffective. It’s hard to jam a repeater that has been turned off on you, isn’t it? Turning a repeater off is my last resort, but please remember…it is my license that is in use as well as the repeater user's, as defined by the FCC.  It is the same as if I had invited hams to my house to use my equipment.

 

For my next blog entry, I think I will start a series on repeater basics.  I hope you will want to read it.  If you like what you see, tell others. If you don’t, please tell me.

 

73 de Tim WB4GBI

 

ITS ON THE AIR!!

 

 

IT’S ON THE AIR!!!!

 

After almost a year of planning, purchasing, installing, connecting, tuning, configuring, spending, crying, praying,  site renting, grunting, more spending,  and just plain old hoping everything worked out,  IT’S ON THE AIR!!! 

 

Please look at the 146.73 web page when you get a chance. Josh McDaniel, KI4WWY, one of my co-workers, took the pictures that you see on the 146.73 web page.  He and Dave, KE4YBZ, assisted me on Wednesday, August 6^th, in transporting the repeater on the mountain.  After 11 months, the dream has come true! 

 

Now, here’s the caveat…it has a duplexer problem. Despite the valiant efforts of Kevin, W4KEV, the duplexer is still struggling.  It has 11 db of loss on the receive side.  What does this mean?  A 3 db loss is considered to be half of the signal in question.  So you can imagine what an 11 db loss is now.   It’s only running 24 watts on the transmit side as well. The coverage ain’t too bad for 24 watts, huh? 

 

I am actively looking for another duplexer.  I hope to have one tuned up and installed as soon as time (and finances) allow.  I am right now over the $3,000 mark in my investment on 146.73. But to see the repeater return to the mountain after all that Sam, WB4HAP,  went through, it’s worth it. I am glad to see it through to completion.   It’s only going to get better!

 

Sam, this is for you. I hope I’m doing OK so far. J

 

73 de Tim WB4GBI

Thank You, Kevin!

From “The Radio Amateur’s code,”  written by Paul Segal, W9EEA, in 1928…

 

The Radio Amateur is:

FRIENDLY...slow and patient operating when requested; friendly advice and counsel to the beginner; kindly assistance, cooperation and consideration for the interests of others. These are the hallmarks of the amateur spirit.

As many of you know, I did not take the 146.73 repeater to English Mountain a couple of weeks ago when I installed the antenna.  At the last minute, I discovered that the duplexer was not performing up to par.  Since I could take the repeater to the mountain a lot easier than I could take the antenna, I went ahead and installed the antenna and line so as to be ready for the repeater to return home.  My access to the repeater site is very limited, and I wanted to make sure everything was ready when I actually put the repeater on the air.

Meanwhile, I asked Kevin, W4KEV, if he would help me with the duplexer. I already knew that Kevin was very talented at tuning duplexers, as he re-tuned a duplexer that I bought for 146.625 that arrived out-of-tune.  Note to self:  beware of promises made on ebay! 

I called Kevin and asked him if he would be willing to help, and he readily agreed. I took the duplexer to his home.  Kevin researched the origin of the duplexer, which we both knew was home built but never knew by what guidelines it was built. We found it on the “repeater builders’ webpage, which is a great resource for repeater owners and trustees.  Kevin also ascertained that the inter-cavity cables were the wrong length, and the output harness was wrong as well. Thankfully, Kevin had more time than I did to test various cable lengths with his sweep generator. If you don’t know what a sweep generator is…well…lets say I was drooling when I saw his.  It generates a “sweep” of RF on a given range of frequencies at a given level.  This allows you to tune filter cavities, duplexers, and any other frequency-sensitive devices with ease and accuracy.  It is very difficult to tune a pass-reject device such as a duplexer without one of these pieces of test equipment.  

After several attempts to get back together with Kevin and test the cables that Josh (KI4WWY) and I had built, we finally met at his home again on Thursday.  Kevin had already connected the inter-cavity cables and was awaiting the output harness cables that I needed to cut to length to finish the tune-up. Kevin took several hours out of his evening time and tuned the duplexer and a filter cavity I am placing on the receive side to allow me to operate the repeater with a receive preamp.  While the duplexer is not perfect, it is a far cry better than it was before.  I left Kevin’s late that evening and took the duplexer back to my shop and restored 146.73 to its temporary service.  It is performing much better, and is ready for its English Mountain trip.  It’s on the air again at my shop if you want to try it out. 

Kevin owns the 145.23, 145.37, and 442.500 repeaters.  He willingly gave his time to help another Amateur repeater owner.  I am very grateful for his time and talents.  I have obviously dealt with duplexers since my repeaters went on the air, but I have never been able to tune them locally.  So, that’s the reason for the quote from the Radio Amateurs code listed above.  If you talk to him on the air, tell him “Thank You.”  This is what all ham radio operators should be willing to do.

 

I hope to make it to English Mountain this coming week.  Stay tuned!

 

 

 

 

 

 

 

 

ALMOST THERE!

 

Many of you have asked, “When is 146.73 going back on the air on English Mountain?”

 

Well, after many months of behind-the-scenes work, I am now proud to announce something publicly. Yesterday, I met the site owner and tower climber of the facility from which I am renting tower space.  With the help of Dave, KE4YBZ (who also maintains my web site- Thank You Dave!),  the antenna for 146.73 has been installed on the tower and the cable has been routed into the building. I have my assigned space in the building.  It was an all-day trip, as it takes over 90 minutes to get to the site.  The antenna installation took place after about three hours of preparation and tower work. The English Mountain site is only five miles from paved road, but it is a five-mile, closed-access mountain road. It takes about 20 to 25 minutes just to get up to the site. But the “hard part” is done!  It was 90+ degrees at the site with no shade. I have a nice sunburn and some yellow jacket stings to show for the effort. I actually got the yellow jacket stings while loading the antenna up at home.  Who said ham radio was painless?  J

 

Now, you might ask…”Why didn’t you take the repeater with you and get it on the air?”

 The reason is that I had a concern with the repeater duplexer that necessitated leaving it here in town and checking the alignment. I hope to have that resolved by the end of the week. Then, I will need to secure a time that I can get access the site to deliver the repeater and duplexer. Please bear in mind that as a *renter* on this site, I have limited access and can only go when I have secured a key to the road and building. However, due to the limited availability of sites on top of English, I am very pleased to have the site that I do.

 

After the antenna was installed, I hooked up my Icom mobile and made a few tests on simplex. Some of you might have heard me or worked me from there. The Antenna checked out fine.

 

 

Hang on…we’re almost there!!

 

 

What have you done for me lately?

 

 

What have you done for me lately?

 

If you are unfamiliar with repeater operation, you might think that repeaters are “plug and play,”  or that you put one on the air that all of the work is done. Not so. A repeater owner or trustee will spend countless hours testing his repeater for coverage, proper tuning, and audio. And this of course doesn’t count, heaven forbid, if it goes off the air.

 

Sometimes, I just pay “social calls” at the sites where my repeaters are, but more often than not, I usually give the repeater a full check up when I visit a site.  What parameters would one check on his repeater to make sure it is functioning at its full capacity? Well, here’s some parameters; I’ll try to give each one of these some discussion in the future. On the receiver side:  Sensitivity, selectivity, modulation acceptance bandwidth, carrier frequency, IF frequency, audio-output symmetry.  On the transmitter side: Power output, spectral purity, deviation, carrier frequency, modulation symmetry.  Particular to repeater operation:  desensitization (“desense”), repeat audio level, time-out timer, hang timer, and effective sensitivity.  It is not necessary to check all of these parameters every time you go to the site, but all of these have some bearing on how well a repeater operates.

 

So…Why the title of this article?  What have I done (for you, the repeater user) lately?  Well, this past Saturday, I spent almost all of the day working on the 146.73 repeater. I am getting it fully ready for its trip home to English Mountain. I am really looking forward to having 146.73 back on the air at English Mountain, where it was for over 25 years.  I hope Sam (WB4HAP, from whose estate I bought the repeater after he became a silent key) would be proud.  Saturday, the repeater was fitted with a control receiver, DTMF decoder, two new fans to cool the transmitter PA, a new rack-mounted electrical strip, and new duplexer cables. The control receiver had some issues, but those were all repaired and the repeater is now fully ready for its homeward trip. I’ll be working on an installation date (hopefully) next week.

 

Today, Sunday, July 13^th, I spent a couple of hours at the 145.17 repeater site in South Knoxville.  The repeater had no repeat audio, and even though it was on the air, it was basically useless; so, I visited that site and gave the repeater a good tune-up. Here’s hoping it works for a while to come.

 

So, even there was no hamfest or field-day type event this weekend, it was a busy ham radio weekend. I hope you enjoy the “fruits of my labors!”

 

 

 

Here goes!

Well, here goes!

Thanks to Moe, N4CQW, I now have the means to "blog." I have read many
blogs before, but this will be the first time to be on the other side of
the keyboard. So, what am I going to write about?

Most likely, you already know me or know of me. You know that I have
several repeaters on the air in East Tennessee. In fact, you probably found
this off of a link from my repeater website. I have had a repeater on the
air since 1981 and was maintaining them a couple of years before that.
Repeaters have been my "niche" in ham radio since shortly after I got my
license. I bought a 12-channel crystal-controlled radio in 1974, and I was
hooked. Not too long after that, I got the chance to meet George Shaver,
K4HXD. He's the fellow that put the very first two-meter repeater on the
air in East Tennessee. George was one of the first people that I looked up
to in ham radio. Later, we worked together and become good friends.

What is a repeater? Well, in its purest form, it's a piece of equipment
that receives and retransmits radio signals. But to me, it's more than
that. It's a community of ham radio operators. Most repeaters have a
"personality." It's a place to rag-chew, conduct nets, meet new hams, and
find help when you have an emergency or urgent need. I'm proud of the
service that my repeaters provide, and I'm equally as pleased that hams
like yourself will use them, enjoy them, and call them you "home" repeater
while you are on the air. Its a priviledge for me to put the repeaters on
the air for you to enjoy. I hope you will enjoy my effort to tell you a
little about them and why I'm so proud of them.

Please check back regularly. I'll try to make it worth your trouble. If you
like what you see, tell your fellow hams.

73 de Tim WB4GBI

test message

Hello and Thank You for stopping by my blog page. I hope you will find it entertaining and informative. Please check back often for updates as I plan on sharing a lot of information about the WB4GBI repeaters and repeater operation in general.  Please email me at wb4gbi@arrl.net if you have any comments of suggestions. I look forward to hearing from you.

 

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

 

 

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

 

 

Test Post

Hi Tim,

What do you think of the colors? These are colors I pulled out of the banner I "stole" from your homepage. Hi hi!

I also have incorporated a email link for people to subscribe to your "new" mailing list on your blog.

Please let me know.

73, Moe