Retevis RT95 Testing Harmonics with a TinySA - Ham Radio

[@ErikKaashoek]

Using LEVEL/UNIT you can switch the level display to watt and after setting the LEVEL/EXTERNAL GAIN to minus the external attenuator you can check the output watt levels The slow update speed of the display after starting the transmit is due to the averaging (TRACE/CALC/AVER 4) being enabled by the MEASURE/HARMONIC function

[@TheSmokinApe]

Thanks for the info Erik, and for all your work on the TinySA 👍

[@ryanhorn4190]

I am fairly certain the Anytone 778UV is the same rig. I have had mine for over a year, it is actually my little base station unitz. Zero issues! Thanks for the video and the reassurance!

[@TheSmokinApe]

I’m pretty sure they are the same as well, glad to hear your positive experience 👍

[@HOAHamRadio]

When Ape does a video, I also realize how much more I have to learn. Thanks for passing on the knowledge.

[@TheSmokinApe]

I just make this stuff up bro!

[@markdoyle8713]

I just learned something. Well done thank you

[@TheSmokinApe]

Awesome, thanks for watching Mark 👍

[@barrykery1175]

Interesting video, but.....the third order harmonic is really the one you need to look at. I sold my TinySA and purchased the TinySA Ultra so I can check not only two meters, but also 70 CM. Time to upgrade ! Barry, KU3X

[@TheSmokinApe]

Yeah, I got the Ultra as soon as they came out.

[@yungsmile7546]

Bought one and it's excellent with my N9TAX 1/2 wave dual band Slim Jim roll up antenna ($30).

[@TheSmokinApe]

Decent radios for sure, thanks for watching Yung 👍

[@StraightOuttaUrbex]

the harmonics and the radio is clean and works very well in the uk

[@TheSmokinApe]

Nice, they are pretty popular here in the US as well.

[@KK6USYHamRadioAdventures]

It looks pretty good need to get some parts for my SA

[@TheSmokinApe]

Get after it…

[@smallick653]

Hey, Nice informative videos . I have subscribed your channel. Keep it up.

[@TheSmokinApe]

Thanks Supratik, glad you like the videos 👍

[@erikas6874]

I may be wrong here, but usually we say "first harmonic" about the fundamental frequency, and second harmonic is the twice this frequency, third harmonic three times and so on. However, my point is odd harmonics as these usually are larger in amplitude than even, probably because of the class C amplifier stage in FM-transmitters. What I find really interesting here is the level of the 3rd, which in this case is 439.560 MHz. I guess the tinySA can't measure this at the "high" input, since the 1st harmonic is out of the range on the low side. But I can be wrong here too, so don't take my words for anything other than just an input.

[@TheSmokinApe]

Hey Erika, I have heard it said a few different ways but I believe you are correct. Also, the low input on the TinySA stops a 350MHz if I remember correctly. Thank you for the comment!

[@paulplack490]

Actually, it's Class B amps (or Class AB) which naturally suppress even harmonics. The Chinese radios often have excessive second harmonics on 2m. This result is encouraging, and this radio at 5 watts draws half as much current as my ICOM IC-2730 at the same 5-watt output. The receiver overloads easily but otherwise, its size, weight, intuitive menus and low current drain could make it an outstanding go-kit radio.

[@CriticalThinker-42]

Another good video! In case of problems with the equipment your testing, I'd show putting a wattmeter inline and test the radios output power into the dummy load Before hooking up the TinySA. I'm sure you'd already tested this beforehand, but viewers who aren't experienced in service techniques need to be aware that just because it Should be transmitting low power, it might be transmitting High power. Don't want to let the Magick Smoke out of our test equipment. EDIT ADDED: I always used a Bird 43 wattmeter to test output power then switched to a sampling slug into the service monitor at the bench (for very high output levels), or a frequency counter out in the field (all output levels). 73 mike N4ONL

[@TheSmokinApe]

Hey Mike, thanks a good idea / tip, thanks for the post 👍

[@gaptastic]

Very interesting. That radio is interesting, but the TinySA is way cool. I was about to ask if you tested the UV5R with the tinyva but looked at your playlist ... and you did! Watching the Baofeng video ... Oops I need glasses ... you did the GT-5R, not the UV5R. Thanks for the video!

[@TheSmokinApe]

Hey GT, I’m working on digging up a new in box 5R.

[@johnflowers1976]

In RF standards testing, harmonics are measured via not just a power attenuator but after this a high pass filter, designed to reduce the fundamental. Otherwise you may just be measuring the harmonic performance of the spectrum analyser front end and not the transmitter. 73 G0JLF

[@Superfandangoo]

It so happens I was reading about this needing to place a suitable highpass filter at the RF input of the spectrum analyzer to decrease its harmonic distortion. I noticed you have been ignored for your helpful advice. 2E0IKJ

[@la7yka]

That is bad practice. Especially as we need the fundamental carrier as reference for the relative dB values of harmonics. A high-pass filter will give wrong readings, as we don't have the exact magnitude of the fundamental, only the power of the harmonics in dBm. And this magnitude (dBm) is what harmonics refers to, as dBc below carrier. An attenuator is of course necessary, so the fundamental is at a level -20dBm or so, far below saturating the the analyzers front end. 73 LA7YKA.

[@johnflowers1976]

@@la7yka - simple, measure the fundamental level first with just the attenuator, then measure the harmonic levels with a HPF (a notch can also be used) after the attenuator, taking into account the additional loss. The difference in results may surprise you, particularly with lower spec Spectrum Analysers. Not everyone has access to high end R&S FSWs or Keysight PXAs! 73 G0JLF.

[@la7yka]

Yes it may work too. 73s - Einar

[@raymondlewis2055]

WHAT!!! You mean my cheap Chinese radio is legal! All the Yeasu FTM400 $500 rigs said no way. Thanks, 73, AA4EZ

[@TheSmokinApe]

Haha

[@cbiz8]

I think that a more valid measurement is with the maximium output, where the endstage works more critical. I understand that the limitation was the low power attenuator, but 5W for an 25W equipment,...mmhh (Sorry for my English, I'm Spanish speaking)

[@TheSmokinApe]

Fair comment 👍

[@2wrdr]

I'm not an electrical engineer but became an electronics technician way back in the early eighties. With that in mind I do know you are spot on in reference to testing at full rated power as this can make a huge difference. With modern radios I'd actually test at both low and high. That said the video still has lots of value in showing the general method for harmonic testing. I love how TSA explains things.

[@Tump2010]

looks nice and clean/within fcc rules.

[@TheSmokinApe]

Turned out pretty good.

[@DonzLockz]

Maybe they added filters as they know you're the only one who checks for spurious emissions. 🤔😁

[@TheSmokinApe]

Wouldn't that be something 🤔

[@KS0JD]

Looks like a good radio! 73

[@TheSmokinApe]

for 125$ its pretty sweet

[@Ibelieve218]

Looks just like my any tone

[@TheSmokinApe]

I believe it is the exact same radio, just a different sticker on it...

[@KempOutside]

Do spurious emissions change with power levels? Would the results change if you were able to test at high power?

[@TheSmokinApe]

They can change levels at different power.

[@theirishoutdoorcook1207]

I was going to purchase this radio but now I’ve changed my mind. I believe the power cord have raw wires and no proper power supply connection.

[@TheSmokinApe]

Yeah, I added power poles to me that easier 👍

[@jayceew2j202]

There’s at least two more models that are copies of this model. Wounder how they paid to the standards

[@TheSmokinApe]

I'm sure they are all the exact same radio 📻

[@BargainBasementHamRadio]

Nice test.....but STOP MAKING ME WANT TEST EQUIPMENT! lol. I have the gear for the power test in the previous video.

[@TheSmokinApe]

Thanks for checking out the video, this TinySA has been pretty fun to mess with.

[@smallick653]

Have you done any spectrum test for any Retivis hand held vhf/uhf walkie talkie? How clean are they?

[@TheSmokinApe]

I have not, I will see if I can get my hands on some.

[@don_n5skt]

I have an RT90 which is actually a Retevis DMR Mobile. Not a good radio.

[@TheSmokinApe]

Is the 90 the mobile?

[@smallick653]

Hey Don, Not good in terms of what ? Emission or user interface or sound quality. Planning to buy one need to know

[@don_n5skt]

@@TheSmokinApe Yes, it is a mobile radio.

[@don_n5skt]

@@smallick653 Both actually. The radio sounded horrible on digital and I got lots of complaints from my club members on audio when using the repeater.

[@mcgrath16511]

ok stupid question if you are using a 40db attenuator, why did you select 20db,,

[@TheSmokinApe]

Hey McGrath. I was setting the internal attenuator in the SA, which isn't really necessary.

[@mcgrath16511]

@@TheSmokinApe Gotcha! thanks!

[@MrDwadi84]

Have you tested any of Anytone DMR HT's?

[@TheSmokinApe]

I have not

[@kchaney56]

Why is all of the onus on us users to decide if a radio is "clean", I do not have the equipment, time, money, or interest.

[@TheSmokinApe]

That’s the rules, probably a carry over from when hams built their own equipment

[@moozoowizard]

please do uv-5r

[@TheSmokinApe]

I have in the past in live streams, I have one here new in box that I will test.

[@paularlukiewicz3384]

The radioddity webaifht ain't working g

[@TheSmokinApe]

Yeah, I noticed it was down…

[@Johnyrocket70]

What does the manual say it's measured at?

[@TheSmokinApe]

It's not in the manual. It's a rule outlines in Part 97: www.law.cornell.edu/cfr/text/47/97.307

[@petenikolic5244]

They should be fitted withan "N" Type Socket not an audio socket so2309 disgusting crap

[@TheSmokinApe]

👀

[@guillote_arg]

Nice test!! This radio is good. Lu3fbm

[@TheSmokinApe]

Thanks Guillermo 👍