How To Request Repairs, Service, Tuning

We only accept duplexers or cavities for repairs, service, or tuning in our shop after discussing your needs and the problems you are having with them prior to them being brought or shipped to us.

In the case of duplexer tuning services, there are a few caveats which you need to keep in mind:

  • Final tuning of duplexers is best done on-site, even if they have been precision tuned here in the lab. See below for an explanation of why that is the case. We offer on-site tuning and final fine tuning for an additional charge within reasonable travel distance, which we will discuss and consider on a case-by-case basis. Regardless of how you get them back, we highly recommend having final tuning performed at the location where they will be utilized. This takes highly specialized, laboratory grade equipment if you want to get the best performance out of them. While it is sometimes possible to do “field tuning” with consumer grade equipment, there can often be a huge difference between professional, on-site tuning with the proper equipment vs. tuning with just a transmitter, receiver, SWR meter, etc. Duplexers are often the critical component that makes or breaks the operation of a repeater or other communications systems and equipment. It doesn’t matter how many thousands of dollars you invest in state-of-the-art radios, antennas, transmission feedline and other equipment… if your duplexers and/or filters are not tuned precisely tuned, your setup will not perform to its greatest potential and — worst case — end up being damaged or causing interference to other stations and systems.
  • We strongly prefer NOT to ship out duplexers or cavities which have been tuned via USPS, UPS, FedEx, or any other commercial transportation/delivery service because any rough handling — unintentional as it may be — can knock duplexers and cavities out of tune, wasting your money and our time. We much prefer that they be picked up by you or your representative and handled with great care during transport. It is okay to ship equipment to us via commercial carrier services which is going to be repaired, serviced, or tuned, but please make sure you ship via trustworthy carriers and insure the package appropriately and use a service with package tracking.
  • Tuned duplexers and cavities can be extremely sensitive to temperature changes because the metals used in their construction expand and contract at varying rates with varying temperatures. These problems are not as prominent with smaller duplexers such as UHF cavities and mobile “pack” type duplexers, so we will consider making exceptions for those. Because of the bulk and weight of larger duplexers they are naturally more likely to suffer bumps and jolts during transport than the smaller ones which are easier to handle, which means you can feel at least slightly more confident that getting your duplexer or cavities back via commercial carrier services will not result in them getting damaged or detuned.
  • We reserve the right to refuse to repair, service, or tune any duplexers or cavities which show evidence of rough handling, improper storage, improper installation, improper use, water exposure or damage, or any other issues which we feel could seriously and/or permanently degrade their long-term performance and stability. A few scratches here and there — along with natural oxidation of metals (within reason) — or minor “dings” in the cavity cylinders are one thing. But if they are seriously dented, rusty, corroded, or show other signs of potentially serious damage which can’t be permanently corrected with confidence, we will advise you to simply replace them.

With the above in mind, contact us by telephone at (334) 787-9005 or email us at to obtain approval and a service ticket number before you ship or bring your equipment to us.