开云体育

Here is the datasheet for the driver module. You are up against it without basic RF test equipment! Q4001 drives Q4006, so you need to know if Q4001 is working · The Drive is up to 50mW, a hand held

Hi Andy, 285mA when I break the jumper and measure across in TX? mode. Max

Is there anyway with the crude test equipment I have I can check for RF on pin 4 of the UHF module? Does the 3.66V on pin 2 of the module sound right?

Hi Andy, Maybe I didn't measure the current correctly. I put one lead on one of the jumpers and the other lead on the other. Tried both ways and nothing either way. On 2m at 50W my power supply

Ok, this is strange. I am struggling to see how you can have 0.7 volts base, 13 volts collector, but no current. That makes no sense. Time to get a bit creative, and enlist the help of your wife. Try

Hi Andy, You should have? 8 volts tx on UHF, pin 1 of J4007 *7.79V* You should have some voltage, less than 8, on Pin 2 of the module. *3.66V* You should have 13.8 on pin 3 of the module, and RF out

Also put an amp meter in series with TPH and 4003 and 4004, that is what it is for, run around 10 Watts and see that to current is, at 50 Watts I would expect 10 -12 Amps depending on efficiency! 73

You need to know the level, however, that sound relativity good news, The PA block may be obsolete, but tricky to test with limited equipment 73 Andrew Sent: 12 July 2022 16:01 To:

Thank you Andy, I will report back.

A very quick look at diagram, you should have 8 volts tx on UHF, pin 1 of J4007 You should have some voltage, less than 8, on Pin 2 of the module. You should have 13.8 on pin 3 of the module, and RF

Yes I can hear the UHF signal quite well on my handheld. But no output power shows on the 847's meter. This is probably the pre-drive signal I'm picking up.

Do you have a vhf/uhf handheld? Use on same frequency, with a carefully positioned screwdriver tip on the input of the driver block. Will give a rough idea if you have drive to module. By going on the

No That is a network analyser, as it has reflection ports and through ports, it is not a spectrum analyser, they are different. 73 Andrew Sent: 12 July 2022 14:41 To: [email protected] Subject: Re:

Looks about the same as what I have...

Ah in that case, buy one of the those small software defined Spectrum analysers, and a few SMA adapters so you can put a scoop probe on it! Look at the single input on the VHF side the UHF will or

I don't have a lot of test gear. Multimeter, small portable scope from Amazon and a NanoVNA.

Trace the signal paths, to the TX PA Sent: 12 July 2022 14:17 To: [email protected] Subject: Re: [YaesuFT847] Schematics? Thank you Andrew, will do. RX on the UHF band is fine. It's just the TX

Thank you Andrew, will do. RX on the UHF band is fine. It's just the TX that has failed. Max

Ah That Kingston, not the one 12 miles from me here in Hampshire ! This should help, check the drive and the VCO locking they do drift out of lock 73 Andrew Sent: 12 July 2022 13:00 To:

Hi Andy, I touched up the both the PCB and the module solder connections. I may just go in and start inspecting solder contacts to make sure everything is good. Voltages would help but I do have the