Re: High pitched tone at 14.074 mhz

John (vk2eta)

On Thu, Sep 5, 2019 at 07:25 AM, Chris [N7CCX] wrote:
"touching the crystals on the raduino or on the board dont change anything"
Hello Chris,

Do you mean both crystals on the Raduino proper and on the Nano's board?

For comparison I do have birdies (mine is a V3) here and there as I have on my FT-817, albeit not as significant as on the uBitx. On the uBitx on 20m band I have two noticeable ones at around 14,006 and 14,179 and an S6 one at 13,996.

Birdies should shift frequency significantly when switching from USB to LSB as the 2nd LO swings from around 57Mhz to around 33Mhz thereby changing the harmonics beating frequencies that can occur on the board.

Other sources of impact on noises could be power supply (switch mode) and location of wires inside the box. Not likely as you mentioned you disconnected the antenna from the board itself.

73, John (VK2ETA)

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