If you want a darn good repeater at a bargain price, look at a Kenwood TKR-750-2 !38-150mhz. The regular TKR-750 will work fine too. The only thing you will have to add to it is a 12vdc power supply. 15 amps is more than enough. These repeaters are work horses and have a built in controller. Sure, the Motorola Quantar and MSR-2000's are great repeaters, but you could by 4 or 5 Kenwoods for what you will pay for the one Motorola. The Kenwood is only a 50 watt repeater max at 50% duty cycle. It is rated at 100% duty cyccle at 25watts. If you want 100 watts, get a 20-25watt in 100watt out repeater amp and a 25 amp supply and you will still have money left over as compared to the Motorola MSR-2000. My company has installed dozens and dozens of these in UHF and VHF models and have had almost no problems. If you loose a power supply on the 100watt MSR-2000, it will cost you as much or more than a new Kenwood TKR-750 repeater. This fact has sold a few of the Kenwoods for us.
Just my $0.02 worth....
73

If you think lightening may be a problem for you, then I cannot think of a better antenna than the DB-420 or even a DB-408.
If you don't have a lot of lightening, then Telewave makes some exellent fiberglass antennas. Their 6dbd works really well. It is about 6 ft tall. Their 10db 20' tall antennas work really well too, but we have lost two of them to lightening and one to bad wind and weather. If you put one on the side of a tower with a a stand off bracket and a top brace, you will probably have no trouble with it.
Andrew (DB products/Commscope) also has a 20' tall fiberglass antenna that works well. Treat it like the 20' Telewave...
Just my $0.02.
73

There are two in my home area. 53.030 output/52.030 input with a 203.5 tone and one on 53.750 output/52.750 input with 123.0 tone. They really do not see a lot of activity, but they are up and running in the Mobile, Alabama area nonetheless...
73 de N5NPO
Norm

I think I can help you out. e-mail me, n5npo(at)hotmail(dot)com.
73

Has anyone ever dismantled one of these? I have 3 with high SWR (low return loss). I have lots of experience with DB224's but almost none on the DB264. Any ideas out there?
Thanks.
Norm N5NPO

I have programmed and tuned a couple down into the 440 ham band with no problems. They are reliable old workhorse repeaters if you don't push them too hard.

I work for a Two Way Land Mobile radio company. We sell Kenwood, Icom, Vertex and M/A-Com (now Harris) equipment. We have tons of Kenwood TKR-750's, TKR-751's, TKR-720's, TKR-850's, TKR-820's, TKR-830's, NXR-700's, NXR-800's and NXR-810's... We have sold a few ICOM repeaters with mixed results. We have also sold tons of the M/A-com Mastr III's.
The Kenwood repeaters are hard to beat. They have mechanically tuned preselectors and are very reliable. If you get a TKR-750/751 (VHF) or a TKR-850/851 (UHF) you should have years of great sounding repeater service. They are about as plug-n-play as it comes. They have excellent built in controllers that will do most any function one would need. Sorry no digital voice ID'er or time announcements, etc...
If I was going to go the easy route to get something on the air quick witout hesitation, I would go with a Kenwood...
Having said that, I have "built" or "assembled", retuned, rebanded and repaired several GE Mastr II repeaters. They are hard to beat. If you can get one, and that shouldn't be to hard, there are 1000's of them out there, you will have a well engineered and reliable machine. So far I have built 3 from peices on 2m and 6m and rebuild countless others on 2m and 6m. I haven't worked on any for 70cm yet, my company used to have a dozen in LTR UHF service and I did rebuild a few PA's.
I have enough parts to built a half dozen more right...

If you have the time, go GE Mastr II. If you don't, go with a Kenwood. You won't be sorry.
just my $0.02 worth.

Service monitor calibration service:

My company used to use EML out of Tennessee. We have now decided to just send our Service monitors to Aeroflex (formerly IFR) for repairs and calibrations. Most of our SM's are Aeroflex/IFR anyway. The Motorola will probably go to EML still, unless it needs repairs, then it will go to Motorola.
73

I am not familiar with that Motorola SM. My company has a Motorola R2550 and I think it is awesome. Easy to operate and not overly burdened with a lot of menues. Only drawback is it does not have a tracking generator.
The mainstay SM at our company is the IFR COM-120B. Ours have the tracking generator option and they work well. Our newest two SM's are Aeroflex 3920's. Awsome machines, but the learning curve is a bit steep. Our units have tracking generators, spectrum analyzers and work on P25 and Kenwood Nexedge modes as well as EDACS and conventional modes.
As far as tuning duplexers, I get the best results using an Anritsu Sitemaster 312D to tune each can for maximum return loss at pass frequency and then use a tracking generator to adjust the notch for the deepest notch at the desired reject frequency. You must tune the pass frequency first and then leave it alone. Moving the pass will affect the notch, but not vise versa.
Site interference is a horse of another color... There is an online intermod calculator on Commscope's website. A spectrum analyzer is of great value.

Could be the PL encode if the repeater is transmitting one. If you are using a scanner, it may not filter out PL tones and often they sound like a low frequency hum on a non filtered reciever.

Jim,
Contact me off list sometime. I may be able to help with some alternative tower sites in your area.
73
de N5NPO Norman Knapp
n5npo(at)hotmail(dot)com

If that DB224 is less than 12 years old, you might want to weather proof all the molded joints with scotch-kote before you put it up. They have been having a devil of a time with water getting into the harnesses.
If you decide you are going to mount on the side of the tower and you want the most omni pattern, you should mount the antenna so that no dipole points to the nearesr tower leg. In other words, the closest to pointing at the tower for any of the dipoles is 45 degreess. That seems to give the best results as far as least interference from the tower.
73

LMR-400....
Get some...

I would go with two sets of guys. One set at 27ft and another at about 54ft. Guy brackets are highly reccomended. I used 3/16 ehs with power line insulators on the top two east side (one goes northeast, the other goes southeast) to make a 75m inverted V and it works great. I used ceramic egg insulators (HEAVY ONES) at the end away from the tower. The rest of my guys have no insulators (GASP!) and I have no problems with my 70' tower. On top I have a 3 element 17m monobander. 3 element 6m monobander and a 5 element 2m monobander. I have a 2m ringo on a stand off at about 50'.
73 de N5NPO
Norman Knapp

I would like to exchange saved files from Yagi for Windows with other ham users. I have been working on some 3 and 4 element designs that I would like to compare with others of you...
e-mail me at n5npo@hotmail.com

73 de N5NPO Norman Knapp