Retevis RT97 Portable Repeater
I have always loved the idea of having a portable repeater. Something that I can put up and take down as needed. To put something together, you normally have to take two radios, a repeater controller, duplexer, antenna system and put them together with all the required cables. So I was really interested when I chanced upon, the Retevis RT97.
It has a strange title on their page, Portable Repeater Power Amplifier UHF. Which made me wonder what it actually is. Once I read through a bunch of blog articles that Retevis has on it, I was able to confirm that it is a Portable Repeater.
In the case, they have a 10 Watt radio, a duplexer, and the repeater controller. The only thing you have to do is hook up an antenna and hook it up some power and you are all set. The size is listed as 310 x 283 x 170mm, which makes it pretty small. For those that use inches, that is roughly 12.2 x 11.2 by 6.7 inches.
It can be programmed with up to 16 channels but there is a few catches. First, the Tx (transmit) and the Rx (receive) frequencies need to be at least 5 (and can be up to 10) Mhz apart, this is called the offset. Second the Tx Frequency needs to be the higher of the two frequencies. Thirdly, the duplexer has be setup for that.
The last one is the one that the average person will not normally understand. Think of it this way, the duplexer is what allows that the system to only one antenna. The duplexer has to be set at the factory to match very discrete range of frequencies. Normally, it’s set center frequency for the Tx and Rx. Once set, it’s hard to change.
The allowable frequency ranges are 136-147 Mhz (VHF) and 400-470 Mhz (UHF). Here in the states, amateur radio VHF repeaters have an offset of only 0.6 Mhz and the UHF is 5 Mhz, which means for only the UHF configuration will work. The US GMRS repeaters are have 5 Mhz offset and are in the UHF range.
As a matter of fact, for me personally, the GMRS configuration would make the most sense (as I have a GMRS license). The local accepted backyard repeater frequencies for amateur radio have the Rx higher than the Tx which this unit does not allow (at least that’s what they claim), while I have an amateur radio license this unit can not do the needed configuration based on my local repeater band plan. In other areas, it might work. Check with your local repeater coordinators.
Edit (2019-05-21) : I was just thinking about this and I might have the above bit wrong. On a repeater the Tx and Rx is reversed from what you set your radio to. So it might work for a backyard Amateur Radio repeater but not as a backyard GMRS repeater. This will be something I’ll have to email to clarify with Retevis.
Edit (2019-05-22) : I contacted Retevis, I was correct in my thinking. I did wonder the way my local backyard Amateur radio repeater guidelines are if this will work. They give a sets of frequency pairs and let one as Tx and one as Rx in each pair but they don’t say if it is for Repeater or for the radio. Guess I will need to email the repeater coordinators for clarification.
I would love to hear from those that might have one of these. At around 400 USD, I think it would make an interesting addition to the gear that some people may use for camping, prepping, or just plan recreational activities. I wish there was a configuration that would work for me just so I could play with one of these things.
For those interested, here are the listed RT97 portable repeater specifications.
1, 16 Channels
2, Offset : from 5mhz~10mhz
3, Output Power: 10W
4, Weight: 2700g( with package)
5, Package Size: 310x283x170mm
6, Can be programmed
RT97 portable repeater Technical parameters:
Frequency Range 400-470MHz/136-174mhz
Channel Capacity 16CH
Channel Spacing ±12.5KHz Narrow/±25kHz Wide
Operating Voltage DC12V ~24V
Operating Temperature -30°C~ +60°C
Frequency Stability ±2.5ppm
Antenna Impedance 50Ω
Intermediate Frequency Customizable
Power Output 10W
Spurious Emission -60dB or less
Maximum Frequency Deviation Wide: ±5kHz Narrow: ±2.5kHz
Audio Distortion 5% or less
FM Noise Wide:≤45dB Narrow :≤40dB
Intermediate Frequency Customizable
Sensitivity(12dB SINAD) 0.2μV (Wide) 0.25μV (Narrow)
Squelch Sensitivity 0.15μV (Wide) 0.2μV (Narrow)
Adjacent Channel Selectivity ≥ 70dB (Wide) / ≥65dB (Narrow)
Intermodulation ≥ 55dB
Spurious Rejection ≥ 55dB
Image Rejection ≥ 55dB
FM Ham and Noise ≤-45dB(Wide) / ≤ -40dB(Narrow)
Modulation Type F3E
Operating Bandwidth ≤±7KHz / ≤±5KHz
Audio Distortion ≤ 5%
1 x Repeater
1 x Charger
1 x Power Supply
1 x Car Charger Cable
1 x Programming Cable
1 x User’s Manual
Price : 399 USD
Thanks to writer Jeffrey P Brissette for writing this aricle.