Why you should do the SAW filter mod to your 1.3 GHz FPV Video Receiver - PK's Lab

Woot, we are back in the lab for another shootout. In this one we're looking at the adjacent channel rejection performance of 1.2/1.3 ghz video receivers and why it's a good idea to swap to a 17 MHz SAW filter if you flying with others in the 1.2 GHz band.
Timestamps:
- What's the SAW filter do? [0:48]
- Where is the SAW filter in our receivers? [2:37]
- The test setup [3:50]
- Why -90 dBm for a reference signal level? [4:41]
- The Shootout [5:37]
- Recap of the results [8:26]
Filter available for purchase here (not affiliate links):
- www.digikey.com/products/en?k...
- www.readymaderc.com/products/...
Relevant Links on the mod:
- www.rc-cam.com/forum/index.ph...
- fpvlab.com/forums/showthread....
- fpvlab.com/forums/showthread....
Please visit: pk-fpv.blogspot.com/ for additional tests and content :).
All tests were performed on retail gear purchased with my own money.
Thanks for watching!
~pk

[@malinhiles]

This video is so valuable. Never bothered to do this upgrade the saws on my receivers in the past. But now having seen your video actually quantifying this pretty significant improvement, I just put in an order from digikey on those narrower saws! Thanks PK

[@hb9hal]

Thanks to your Video I noticed to use my SMT 03 for the same sensitivity test too!

[@jorgelbotelho8363]

Show!!! PARABÉNS

[@aidanmcgee5900]

Hi, love the videos. Is it worth changing saw filter if I’m flying solo in a remote area. I use a 868mhz frsky R9 radio tx to control plane. Not sure if I would benefit? Cheers

[@PKsLab]

It will improve how the module behaves as you approach sensitivity. Without it, you'll get black and white specs in your video well before you drop to black and white. This is because the actual occupied signal is narrower than the stock 26 MHz SAW filter, so that additional in-band noise results in a degradation of the demodulated video signal.

[@MrDrivesafe]

@@PKsLab Excellent, thanks for the video post and the response to Aldan's question, I was wondering the same thing.

[@AjmalYakoobMMAMuayThai]

Hi i would appreciate if u can suggest me 1.3ghz fpv set with audio enable, so. I can listen to sound as well, Thanks

[@mitchellroberts7954]

Have you been able to look at the internals of the newer RMRC 1.3ghz digital display Vrx to see what saw filter it comes with? Been waiting weeks for a reply from RMRC.

[@PKsLab]

I picked up one of the newest one that they just restocked last week. It looks to be using the narrow 18 MHz SAW. But it's behavior as things get down to sensitivity isn't super (wavy video). This potentially indicating a different amount of de-emphasis is being applied to the baseband video signal at the RX side. But I only have one unit and have been busy being a dad. Don't hold your breath on me getting to the bottom of things anytime soon ;-)

[@mitchellroberts7954]

@@PKsLab your findings are consistent with my testing in the field. I picked up one of the 4ch older versions per your recommendation off the member of rcgroups. That explains why I found a wall at 18-22mi when I could go 20mi on 5.8ghz 🤨

[@mitchellroberts7954]

@@PKsLab FWIW the wavy behavior occurs as close as 5-10mi. Very strange.

[@pedrofdmp]

How did you manage to remove the saw filter? Haven't been able to get mine out no matter the amount of heat or pressure :|

[@PKsLab]

Solder wick to clean up each pin can help if they are stubborn. A hot air rework station also can help.

[@pedrofdmp]

PK in the end i had to apply heat directly on top of the filter can since it had solder underneath

[@snakes301271]

cant find these SAW filters anywhere in the UK! anyone any ideas?

[@FasterThanJesus666]

try Farnell or radionics