EEVblog #1275 - Uniden UHF Walkie Talkie Teardowns

"Copyright 2000" ... hold on I thought he said 20 years ago ... oh :(

My grandparents have been using those old school Uniden uhfs daily for 16 plus years on the farm. They have held up surprisingly well.

That 5-watt "professional" model might be more expensive materials, but Vietnam is where you go these days when Chinese labor is too expensive...

10:30 solder balls, coming to a short near you!

Oh man I just had the exact thought about these last summer. I bought a few of these in 2001 for chatting when off-roading when we were out in our Jeeps. Fast-forward to 2019 and went shopping for some 'real walkie-talkies' for my 4 and 5 year olds to play with and to my amazement they dropped to like two for $30. They arrived and they are absolutely tiny. Blew my freaking mind. We have since bought them for all the neighbor kids and now they all play with them all the time.

13:00 That's most likely just an RF-MOSFET. Those RF-FETs typically have the source on the cooling pad for good low-impedance grounding. I see an RC feedback network from drain to source (very common!) and a matching/filtering network to the antenna. The diode marked "W4" looks like a PIN diode for the RX-TX switching (there is a second one under the edge of the shielding can). It's actually a quite nice design, as soon you switch on the drain voltage BOTH diodes are going to conduct and you connect the TX to the antenna, and short the RX input to ground to protect it. The SOT23 would then be a bias regulator, since they would be using the FET in Class C there is no idle current, you just have to bias it somethat under Vth to get the right conduction angle. So no adjustment needed here.

2:38 Shoutout to Dave chortling at "People's Republic" LOL! 10 for style and finesse!

you saved the new transceiver from an untimely death by removing that solder ball

The UH040s were a classic. Top seller and top performer. >50 km range from a high spot. The use of AA (not AAA) batteries was a masterstroke for long life. only thing extra I'd have liked is a detachable antenna. From memory they were $149 when they came out, dropping to $99 for a long time.

When I was a kid in the 90s I had a rich friend that got very fancy walkie talkies that we used to play around. I was amazed by them at the time.

Nice to see a longer Teardown Video from you again! Godspeed!

the remarkable thing is that the 15$ kid transceiver is 75% empty. The board is massive but there's almost nothing on it. It literally has that size so that the batteries and the LCD can fit on it without cables

Is not a CB radio 27MHz !!! Is a PMR radio 446MHz !!!

I always love a teardown and one of the few fun parts of taking apart printers is seeing the evolution over the years from different companies.

Videos like there, where Dave gets all hopped up and his passionate Aussie side comes out, are the best. Can always tell when he's REALLY into a topic like this one. Again, fantastic video Dave. As for Uniden, we all remember these from the Radio Shack/Tandy store days. Always have been a high end brand, even today they stand up there with Kenwood and the lot.

That was tremendous fun. Thanks Dave

that is so bloody weird - I literately just took some of these exact same walkies apart about 30 minutes ago

Lovely. Teardown & RF. Great match!!!

I have a beautiful TRC-236 Radio Shack Citizens Band transceiver. Got it at a yard sale for $4.00. The only thing I had to do to it was make 2 blank batteries (according to the manual) for the proper voltage, using alkaline batteries. If you're using rechargeable they are not necessary. It is a beautiful piece of vintage electronics, in fantastic shape! *Edited to add. It picks up the truckers on the interstate 7 miles away.

Hi Dave. A very interesting teardown, thank you. The RDA chips are also the core in Baofeng VHF/UHF transceivers. One minor thing to clarify: all of them are PMR (446MHz), not CB (27MHz). Cheers, take care!