Jeff Welton, has worked with Nautel for 24 years. He is currently the Nautel Sales Manager for U.S. Central Region but previously he spent 16.5 years as a Nautel Customer Service Technician.

Submissions for this Tips ‘n Tricks column are encouraged and if published you’ll receive a Nautel T-shirt. Submissions should be typed and emailed, with high resolution photos, to [email protected] using the subject line Tips ‘n Tricks.

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The UPS Interface Option, by Jeff Welton


A lot of folks have asked me, “what’s this UPS Interface option on your proposal?” They ask me that because I tend to make it part of every proposal I send out. In this issue, let’s dig into the UPS interface option and what it does – note that it’s available for all NV and NVLT Series transmitters.

On a short interruption of AC mains, as expected, the transmitter goes down – it does this because the power supplies discharge very quickly under load, with no mains present to keep them up. So when the mains voltage returns, the supplies need to charge and stabilize, then the exciter needs to restart itself, as does the controller and AUI, then the amplifier stage(s) need to be restarted. Although the AUI itself can take upwards of a minute to go through the start-up process, the other parts of the process are fairly fast, so the transmitter will be back making power quite quickly after a mains interruption – but it still means a loss of air time in the order of three to five seconds longer than the actual power interruption.

The UPS interface allows the customer to connect their own UPS between a wall outlet and the transmitter. Effectively, it provides a connection point for the UPS output and uses that source to drive the exciter(s) and low voltage/controller power supplies. The UPS should be double conversion, although single conversion will work in most cases. It doesn’t need to be that large – 500VA is adequate for most cases, with 1kVA being a very acceptable size. Since double conversion UPSs in the sub-1kVA range are less common, this seems to make a good compromise.
Another concern is having to take the transmitter off-air for UPS maintenance, or having it go down in the event of a UPS failure. The easy solution is to only connect the UPS to one set of exciter(s) and power supplies (this assumes there is a second exciter provided in the transmitter). In this manner, the UPS can provide backup for the primary exciter and, in the case where the UPS itself fails or needs to be removed for service, the alternate exciter can operate the transmitter from AC mains power.

Not to worry if you’d assumed that the UPS Interface meant powering the entire transmitter from an external UPS and didn’t request that it be added – it’s available as a field installation kit for NVLT Series transmitters, with a quick install guide.


For NV Series transmitters, it can also be field installed, but be warned that we may still have to create documentation for some systems and this could slow things down. However, Customer Service can talk you through how to install an external UPS without the formal field upgrade – which simply adds power connectors to the roof of the NV Series transmitter for ease of UPS connection.


Give your Sales Rep or our Customer Service Department a call, we’ll be happy to help you out!
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Side Note

Our VS and NVLT Series transmitters have remote control via a DB25 connector. I am sure you’ve got other equipment around the station that also uses DB type connectors for interfacing and I am equally sure you probably don’t get overjoyed when you have to solder one together. I found this online recently – it’s a Michigan based company that makes a small footprint DB series to Phoenix terminal breakout assembly that looks like this…
You can find them online, at

Until next time, play safe and have fun!
Submissions for the Tips ‘n Tricks column are encouraged and if published you’ll receive a Nautel T-shirt. Submissions should be typed and emailed, with high resolution photos, to [email protected].

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