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On Mon, Dec 17, 2018 at 03:28 PM, Woody wrote:

www.albe24.com

Thanks, wow you have quite a lot of home brew builds!? Very nice.

Sean

Glad you may have found it. Sure, bridge any similar value cap you have. You can even temporarily,? or permanently install the leaded cap on top to see if audio is restored.

I have certainly used leaded parts on surface mount boards, its nothing to fret about.

BTW smt caps when you have them tend to be easy to install with their higher mass than many other parts. But use what you have, and enjoy the radio. Good eyes in your discovery.

Curt

Hi Sean,

It's no problem to use a conventional part with leads if you want.? You'd just have to be careful that the connections don't stray onto other pads.? If you have room, you can just tape the part down near pads, then push the leads down onto the pads, clip off the excess and then solder.

73,


Mark.

Take two 15-30 watt irons . Heat them both . Hold one om each hand. Place tip of one on one end of part place the tip of the other on the other end of part. Slightly press the tips together and when solder melts lift part off the board. Clean up pads with solder braid. Get some paste flux and put a small amount on the pads.Using tweezers place the new part on pads. Put a small blob of solder on tip of iron place tip on one end of part and pad at the same time (hold the part in place with a small screw driver until solder flows. Repeat exactly for other side of part.
I used this method several times a day for 10 years while working as a repair tech in a manufacturing company.

The PDF is of what the etched board looks like.? For most PC board generation, the image must be flipped to reverse.
_W_

On 12/17/2018 23:38, Woody wrote:

Dave,
It occurred to me that the to-scale PDF of the preamp/filter board and parts layout are not in the zip file.
Those are attached...

Woody

--

John

I just assembled the simpler nd6t agc, one npn plus one mosfet. I left room on the board to update it to the other circuit. The first 20 dB may be enough as I am used to the k2 limited agc. I can't get it installed for a couple weeks. Yes lets trade notes.

Curt wb8yyy

Dave,
It occurred to me that the to-scale PDF of the preamp/filter board and parts layout are not in the zip file.
Those are attached...

Woody

Hi Dave,

I think all (more than?) you want to know can be found on my web site,? www.albe24.com
Need to scroll down and click on the Amateur Radio section, then to the uBitX.
The thumbnail image is a link to a ZIP file with the most pertinent information on my build.? It is about a 4 meg file.
The direct link is:? www.albe24.com/kz4akubitx.zip

Hope this helps.? I think everything is now accurate!? Let me know if more info needed.
Woody
--------------------------------------

So last week I said that there was an audio hiss, but no signal on my UBitx v4. I think I may have traced the problem. The capacitor C4 seems to have been mechanically scraped off the board. My surface mounting skills are not up to much. Am I best trying to bridge it with a conventional 100 nf capacitor, try to get some surface mount or get a replacement board.
What are the vendor like at sending out replacement boards? Any idea how much the board would be?

Best wishes

Sean 2e0sfq

Sent from my Huawei Mobile

Possibly for some less expensive alternatives can see this message chain

https://www.eham.net/ehamforum/smf/index.php/topic,123052.0.html

Hi,

I've been following these replies with interest. Lots of practical information on what the trade-offs are vs cost of the rf-explorer vs a full spectrum analyzer. Particularly the signal levels to avoid self generated spurs and the resulting rise in measurement noise floor, and workaround manual measurements. (If I have time to continue with my homemade SDR SA, I imagine the overload vs noise floor levels will be a significant issue, also). One person reminded me of the value of a tracking generator for testing and adjusting filter designs.?

It looks like the rf-explorer may be better than my homage SDR SA project; at a reasonable cost. Comparing those choices, the rf-explorer seems to be the best choice. After, the dust settles on some of my client projects I can decide if I can justify the cost of a real SA for some future projects. Temped to go ahead and get the rf-explorer in the meantime. ?

Tom,
wb6b

Hi do you have the files for the RF pre-am and the agc?
Hard to see the pic there do the files specify exactly where the connections go to the main board?

Thanks

Tried that it's hard to actually even record my volume is so soft to start out with.? But from what I can tell it's seems to be tuned about correct.

Receive frequency seems perfect though so if I change it that would impact my receive frequency also right?? BFO sounds spot on for the receive.