LMX2820 PLL board on eBay

[klondike]

Hi,

Has anyone tried the LMX2820 22Ghz PLL board on ebay? How good or bad is the phase noise performance with the stock configuration?
I'm planning to feed it with low noise Wenzel ocxo to use as low noise LO for phase noise measurement.

https://www.ebay.com/itm/296126831458?_trkparms=amclksrc%3DITM%26aid%3D1110018%26algo%3DHOMESPLICE.COMPLISTINGS%26ao%3D1%26asc%3D261797%2C261915%26meid%3Dfff7824392474bb385f6b72d9f1c8f42%26pid%3D101196%26rk%3D1%26rkt%3D12%26sd%3D355317151095%26itm%3D296126831458%26pmt%3D1%26noa%3D0%26pg%3D4429486%26algv%3DCompVIDesktopATF2V4WithDefaultIMAFeature%26brand%3DUnbranded&_trksid=p4429486.c101196.m2219&itmprp=cksum%3A296126831458fff7824392474bb385f6b72d9f1c8f42%7Cenc%3AAQAIAAABELHyIAEaemKG0mx4REjf%252BHyi2kzcINSWjmv491TDyjbVmYwevKj0ejii%252FeyFe06fKmTkTSCNhTtVKu2TqNYMpWWHBkyu%252B%252FH%252BuDq9PHY4U%252BQf5%252Fq1TiycCEUbygfx1E2hCp%252FRANSFcwChgC2eDyyqSsFtDkXVyEJTLIp0mEKK%252Fh6BYBiSfHN1e2HeKufzXZP1p1En%252F5y%252ByK9%252Bp%252Fxpg%252BttWloDgstzteYa6R%252BMTtCKthQ%252Fh5UzLT8iC7Mi08eTklLqv0CCW%252Feui9Wlq%252BVPNW%252BvkYWqvyMWXGQCcGz8FtWkSOQWRVWZC7GyXbysc8uNiBo17patDIHF4PDM733YBeOPX1eMC%252FokGtu%252BGtya1vp7RkFr%7Campid%3APL_CLK%7Cclp%3A4429486&itmmeta=01HR98HCDKTPFV9NT4QGGXEJB0

[rfdave#gmail.com]

It's certainly not going to be any better than the datasheet performance, so that would put a floor on the expected performance. The OCXO will only improve performance at BW inside the loop filter BW. The loop filter is external, so you can tweak that somewhat.

[Aiy]

It certainly is an interesting board.
I didn't know they were this cheap.
I'm probably gonna get myself one for experimentation

good find!

Best regards

[jayk]

Definitely cheap, but that's at most a TCXO (not an OCXO) and it would have been nice if they'd matched the length of both differential outputs.

[Verticon]

Hi,

these boards are damn cheap. The price at Mouser is roughly 115 EUR (quantity 1) for the LMX chip only. Therefore I wonder if they use low quality chips. It also seems that they use simple FR4 material which could explain the level decrease at the high frequency end.

Best regards