开云体育

Jerry, My Q13 is running uncomfortably hot. The static dissipation without RF is greater than the rated 225mW. Farhan is aware of this and a change of one or two resistors are in order. Cheers Raj

Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the BITX20 group. File : /LED for BITX.jpg Uploaded by : vu2pop

Sorry guys , heres the foto attached Hi , You may see the attached foto , zoom in to see the red & green wires soldered to the DIP relay points Green for Rx and Red for Tx which is fed to the

Hi , You may see the attached foto , zoom in to see the red & green wires soldered to the DIP relay points Green for Rx and Red for Tx which is fed to the dual color LED ( three terminal type) the

I ordered the upgrade on 12/23 and haven’t heard a thing yet. Mark K3MRK Sent: Wednesday, January 04, 2017 6:42 PM To: 'BITX20@...' Subject: RE: [BITX20] the arrival December

Transmitting into a nearby antenna could take out Q13. The base of Q13 is coupled to the antenna during RX (and when the power is off) through a 0.1uF cap, and is the first part I'd expect to blow.

A diode ring mixer is inherently a non-linear device. Look at the voltage curves for diodes and you will see that there is a floor near the inverse voltage that guarantees that there will be never be

Thanks Joel - that's one of the pages open at least twice in this stack of Chrome tabs I'm trying to wrap my head around. ;) I don't have an o-scope yet so my 'noisier' comment was also a

With a diode ring mixer, those diodes are pretty much either conducting or not conducting. So the action of the mixer is a square wave, even if you feed it a nice clean sine wave. Given the

I think John may have nailed it. Quiescent voltage at the emitter of Q13 is around 3.1 volts, so current is 3.1v/100ohms = 31ma, which is ok Quiescent power dissipation is (12-3.1)*.031 = 276

It stopped transmitting after I transmitted on my nearby 100 watt transceiver. The antenna are kinda close to each other. Not sure if it was a coincidence or not. I'll keep an eye on it. Thanks

Joel At the time I built Pete's LBS, our club group build bought them. The library is bad. I'm using it to test the Bitx40 and intend to get another SI5351. Jason's sounds like a good choice. 73

I thought that a pure sine wave was best. Isn't a square wave a mix of waves? That would result in all sorts birdies and products? BITX20@...> wrote:

Ken, I have used the Adafruit boards before too, but the Etherkit boards use a TXCO crystal for better temperature stability and the are only a couple of bucks more, plus I like to support Jason, NT7S

And I am using the Adafruit SI5351. 73 Ken BITX20@...> wrote:

Jerry, Im using the Etherkit Si5351 breakout board. https://www.etherkit.com/rf-modules/si5351a-breakout-board.html Joel KB6QVI

Well, I'm not sure photos would do, and it might take several. Plus there's 20 minutes of disassembly and re-assembly - it's screwed to the box...! However if you look at the schematic - lower left:

I'm no RF guru, but had thought a diode ring mixer would be fine with a square wave LO. Would be interesting to hack the analog VFO to give a square wave at the same amplitude as the Si5351, see if

Thanks Joel. Since I built it, I may as well use it. 73 Ken BITX20@...> wrote:

Ken, I also noticed a clean output after the LPF with Phase noise as well, but I also noticed a lower background noise floor in receive, in fact I'm very happy with it now. If it wasn't for the hiss