Nice video and thank you for the shout out. I like the way you did the “air gap” test. The FCC does specify that it’s measured at the radio output thought. One thing to consider is that the transmitting antenna may not be a match on the harmonic frequencies and attenuate the signal in those ranges. Also, you might want to increase the span so you can see if there is a third harmonic. Thanks for sharing that video 👍
3rd and 5th harmonics will be done in a follow up video later this week. Wanted to hit any harmonics in the 200-300 area first as that sometimes gets overlooked. But, I foroget to mention that. Standard lab tests also can be manipulated based on power level of transmitter to trick some compliance tests only looking for dbm but ignoring what level of attenuation is used to say knock down a 1W, 10W and higher. I think this is how "some vendors" sneak crappy product on to the market. Most vendors do list SAR reports on FCC site. The FCC ID does not show up, just like the HD1 which had pre certification ID and never got a final one. HD1 didnt get its ID until almost 2 years of being on the market and available for purchase.
@@hvdnmedialooking forward to the video. One radio I tested, the manufacturer told me they “fixed” the harmonics but all they did was greatly reduce the power output 😂
I've seen more than one manufacture also label their radios as "GMRS" (usually without Part 95 certification). This seems to be some legal flim-flam to sell non-Part 97 (ham) compliant radios. In my experience, a large amount of the "budget" radios are so dirty that a box of Tide wouldn't clean 'em up. I've also had some discussion with one manufacturer, who pretty much indicated they didn't make the radios, they just put a pretty case/label on radio guts, and they couldn't afford to actually test radios. As @thesmokinape mentioned, the official tests are not "air gapped", they would be direct to the RF input of a test device. Almost all test devices(even the TinySA) can specifically account for attenuation (by mathematically subtracting it out), so input attenuation does not shield any potential issues. I can't speak specifically on the Tiny SA, but even a sub-1000$ SA can detect signals down into the -150dbm range, so after subtracting attenuation, it still will show a clear indication of true signal levels. The other issue as TheSmokinApe mentioned is how well of a match the transmitting antenna is on the harmonic frequencies (which it probably won't be - therefore reducing power on the harmonics). Air gap testing, while a "real-world" look, doesn't rule out background noise and RF that could actually make the radio look worse than it is. A more interesting real-world demo is to tune another HT to the harmonic frequency at the same time. I've tested radios that were so bad, the harmonics at 293 and 439 we clear and readable on other HT's. Never will you find a more wretched hive of scum and villainy...
Thanks from the Peekskill-Cortlsndt Amateur Radio Association, W2NYW, for your review. I didn't there was an Alience HD2 model. I have the older HD-1, which I like that has had DMR for quite a while.😊
Thanks and nice that you are local. I know a few people in your club and always enjoy reading your great newsletter. Curious, on your HD1.... which FCC ID does yours show?
@hvdnvideochannel9253 Hello, yes we enjoy the PCARA and Malclm, NM9J does a great job with our newsletter for almost 25 years. My Ailunce HD1 FCC ID is 2AAR8AILUNCEHD1. Thanks 😊
I did a very unscientific experiment, comparing my ID-52 to an HD2 to. These were the results on the first 3 harmonics: ID-52 146.4 -51dbm 292.8 -97dbm 439.2 -96dbm 585.6 -108.3 HD2 146.4 -51dbm 292.8 -85.7dbm 439.2 -61dbm 585.6 -91 I used an SDR, set the gain setting exactly the same for all tests. Yeah, obviously not seeing a 40db attenuation on the HD2 on the second and third harmonic.
Thanks for your measurements. Will give you a shout out in upcoming video where am doing the same thing mostly. Had to do the other two first just posted comparing the HD1 to HD2 and a basic inside look at the HD2.
Nice video and thank you for the shout out. I like the way you did the “air gap” test. The FCC does specify that it’s measured at the radio output thought. One thing to consider is that the transmitting antenna may not be a match on the harmonic frequencies and attenuate the signal in those ranges. Also, you might want to increase the span so you can see if there is a third harmonic. Thanks for sharing that video 👍
3rd and 5th harmonics will be done in a follow up video later this week. Wanted to hit any harmonics in the 200-300 area first as that sometimes gets overlooked. But, I foroget to mention that.
Standard lab tests also can be manipulated based on power level of transmitter to trick some compliance tests only looking for dbm but ignoring what level of attenuation is used to say knock down a 1W, 10W and higher. I think this is how "some vendors" sneak crappy product on to the market. Most vendors do list SAR reports on FCC site. The FCC ID does not show up, just like the HD1 which had pre certification ID and never got a final one. HD1 didnt get its ID until almost 2 years of being on the market and available for purchase.
@@hvdnmedialooking forward to the video. One radio I tested, the manufacturer told me they “fixed” the harmonics but all they did was greatly reduce the power output 😂
I've seen more than one manufacture also label their radios as "GMRS" (usually without Part 95 certification). This seems to be some legal flim-flam to sell non-Part 97 (ham) compliant radios. In my experience, a large amount of the "budget" radios are so dirty that a box of Tide wouldn't clean 'em up. I've also had some discussion with one manufacturer, who pretty much indicated they didn't make the radios, they just put a pretty case/label on radio guts, and they couldn't afford to actually test radios.
As @thesmokinape mentioned, the official tests are not "air gapped", they would be direct to the RF input of a test device. Almost all test devices(even the TinySA) can specifically account for attenuation (by mathematically subtracting it out), so input attenuation does not shield any potential issues. I can't speak specifically on the Tiny SA, but even a sub-1000$ SA can detect signals down into the -150dbm range, so after subtracting attenuation, it still will show a clear indication of true signal levels. The other issue as TheSmokinApe mentioned is how well of a match the transmitting antenna is on the harmonic frequencies (which it probably won't be - therefore reducing power on the harmonics).
Air gap testing, while a "real-world" look, doesn't rule out background noise and RF that could actually make the radio look worse than it is. A more interesting real-world demo is to tune another HT to the harmonic frequency at the same time. I've tested radios that were so bad, the harmonics at 293 and 439 we clear and readable on other HT's.
Never will you find a more wretched hive of scum and villainy...
Thanks from the Peekskill-Cortlsndt Amateur Radio Association, W2NYW,
for your review.
I didn't there was an Alience HD2 model. I have the older HD-1, which
I like that has had DMR for quite
a while.😊
Thanks and nice that you are local. I know a few people in your club and always enjoy reading your great newsletter. Curious, on your HD1.... which FCC ID does yours show?
@hvdnvideochannel9253 Hello, yes we enjoy the PCARA and Malclm, NM9J does a great job with our newsletter for almost 25 years.
My Ailunce HD1 FCC ID is 2AAR8AILUNCEHD1. Thanks 😊
I did a very unscientific experiment, comparing my ID-52 to an HD2 to. These were the results on the first 3 harmonics:
ID-52
146.4 -51dbm
292.8 -97dbm
439.2 -96dbm
585.6 -108.3
HD2
146.4 -51dbm
292.8 -85.7dbm
439.2 -61dbm
585.6 -91
I used an SDR, set the gain setting exactly the same for all tests. Yeah, obviously not seeing a 40db attenuation on the HD2 on the second and third harmonic.
Thanks for your measurements. Will give you a shout out in upcoming video where am doing the same thing mostly. Had to do the other two first just posted comparing the HD1 to HD2 and a basic inside look at the HD2.
Ailunce is pronounced like Balance without the B.
Thanks for that valuable feedback......