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!