Our customer Oleg Popov reviewed the Retevis RT29, and test the waterproof and power.
About the Retevis RT29:
Frequency range: VHF range: 136-174MHz or UHF: 400-480MHz
Three levels of transmitter power: High 10W, Middle 5W, Low 2W
Receiver sensitivity ≤0. 3uV
Channels: 16 channels (programmable from a computer)
Weight (with battery and antenna) 335 g
Battery: 3200 mAh battery (li-ion)
Waterproof: Water-Resistant IP67 (immersion in water for 30 minutes to a depth of 1 meter)
The difference in price between the Desktop version and IP67 is only $ 5
I took Retevis RT29 VHF: 136-174MHz IP67
I chose this range = for the forest and intersection (VHF in the forest flies better and further).
Who needs a radio station in the city, take UHF: 400-480MHz
I took Retevis RT29 as a companion radio for Retevis Ailunce HD1
Maximum compatibility: Same manufacturer, Same housing, size and weight, Fully interchangeable batteries, Fully compatible charging cups, Fully compatible accessories (programming cable, headset, antennas), Equal power and sensitivity (for Ailunce HD1: in analog mode)
A video about waterproof testing from YouTube:
Retevis Ailunce HD1 vs Retevis RT29 compariso
The antennas are the same in appearance.
But the HD1 has a dual-band antenna, while the RT29 has one antenna. It’s for the better, single bands always work better.
The antenna on RT29 showed very good parameters: a wide range and excellent SWR
And on tidy – quite a beautiful picture:
From the seller, the channels were programmed as follows (saved just in case):
I measured with an OPEK SWR-8 showmeter what real power the radio station produces for a load equivalent of 50 Ohms at different frequencies and different power levels.
Everything is in order: the radio station honestly issues its 10 Chinese watts.
u sort of, that’s it. Now it remains only to decide what frequencies to flash and you can go to test in the ‘field’
Program RT29 v1.1.1
In the program, access to the setting of the frequency of transmission and reception = Low level.
That is, there is no reference to a specific step, the frequency can be set with a resolution of 0.00001 MHz.
And the set frequency is actually written into the radio station, and the radio station actually generates just such a frequency!
About how to program the RT29, you can find here: http://blog.retevis.com/program-rt29-radio/
Why is it good?
The heart of any frequency synthesizer is quartz. And any quartz has parameter tolerances – some kind of frequency spread +/- on the declared one and some floating frequency dependence on temperature.
For example, the following tolerances are claimed on the Retevis RT29 radio station:
Frequency stability ± 2.5ppm
Max frequency deviation <2.5KHz
that is, if we set the frequency to 145.00000 MHz, in reality in a radio station it can be between 144.99975 – 145.00025 MHz.
Deviations seem to be small … But if the deviation is down for one radio station and up for the other subscriber, the communication range can be shortened by tens, or even hundreds of meters …
Measured his radio stations. When setting the frequency of 145.00000 MHz in my instances of radio stations:
Retevis Ailunce HD1 outputs 145.00001 MHz to the frequency counter
Retevis RT29 provides 144.99989 MHz to the frequency counter
So, it seems, it’s normal.
Even, somehow I didn’t really like the digits on the transmitter power measurement. This is when I measured the equivalent load of 50 ohms
Today I took measurements for the real load – the external base antenna COMET GP1M 144/430 MHz
It seems like a nicer picture. Closer to how it should be in theory … but all the same, the numbers are jumping .. Either my Chinese indicator shows the weather on Mars))), or the power output in the radio station is very dependent on the SWR in the load.
But, then, in general, everything is fine: a 10-watt radio station pumps, the power level is adjustable.
Tomorrow, perhaps, I’ll go to try the communication range on the ground. Particularly curious is how cool the VHF is able to bend over the hills. For the sake of what more this radio station was bought.
Well, in the forest, of course, it’s also interesting to test and compare with UHF radio stations.
If any question about this blog, please comment below!