Do you hear loud popping noises as you install antenna to connector.

I have soldered for 55 years Have used the bulb style with the teflon tips. It has only been recently that I have tried working on sm parts All my equipment has been too big.

I saw the post by Art and found this desoldering iron. Every hopeful.

I have never used a solder sucker on surface mount parts.
I don't think I would find much use for that particular tool,
even on through hole parts.

You do want a soldering iron with a very small tip.
Should have thermostatic control of heat, preferably with a knob to set the temperature.

Removing a surface mount resistor or cap, I use two small irons, one on each end
With a wider tip that can touch both ends you could get by with one iron, but I find two easier.

For something like a 3 pin transistor in a SOT-23 package, I first wick excess solder away
with copper braid and some flux.? Then heat and lift the lone pin on one side.
Then heat the other two pins using two irons.

For parts with more pins than 3, I cover nearby parts with tinfoil and hit the part to be removed
with a hot air gun.? An embossing gun (under $20) is sufficient.
Gently lift while heating using tweezers or Xacto knife, but don't tug too hard
or you will lift?pads and traces right off the board.
When the board is hot, the glues holding down the copper are not very strong.

Removing parts can be made much easier with a low temperature solder such as Chip Quik.
First remove as much of the old solder as possible using solder braid and flux.
Then apply a little bit of the low temperature solder to each pin using a soldering iron.
It now takes very little heat from a heat gun to remove that part.

Jerry


On Thu, Dec 6, 2018 at 04:30 AM, d balfour wrote:

I have soldered for 55 years Have used the bulb style with the teflon tips. It has only been recently that I have tried working on sm parts All my equipment has been too big.

I saw the post by Art and found this desoldering iron. Every hopeful.

I have soldered for 55 years Have used the bulb style with the teflon tips. It has only been recently that I have tried working on sm parts All my equipment has been too big.

I saw the post by Art and found this desoldering iron. Every hopeful.

On Dec 6, 2018, at 06:55, Bill Cromwell <wrcromwell@...> wrote:

Hi,

JoshuaClough4 starts his post with his SDR. I have been playing with SDR a little and with "legacy" radios for a long time. That SDR can be and probably is being pushed *hard* by rf being generated right next to it - in the same room, in the same house, on the same estate. Not in the next state. There are so many ways with that kind of proximity to overload the receiver.

Inside the transmitter the carrier and the opposite sideband are fully present. The signal is processed to remove the carrier and the opposite sideband and then send it to the antenna. But due to varying amounts of leakage they are always present on the same estate, in the same house, and even down to a couple of inches away from the transmitter. A new ham who would just casually tweak those pots while watching the SDR may be one of the new hams who denies that a shielded box is needed for the receiver AND for the transmitter.

Just as a suggestion..reset those pots following the directions for the radio. And then leave them alone until *after* you have installed replacement transistors. Then lookup a WebSDR station within range of your transmitter but still hundreds of miles away (well beyond your local leakage). Examine your signal as seen from afar without having to enlist some other ham to look at it from afar on one of those dreadful "legacy" ham stations :) Back in antiquity we relied on distant friends to examine our signals from those distances. Now we can do it ourselves via WebSDR so the receiver is beyond the "local leakage".

I mentioned newbie mistakes and misunderstandings. Somebody is going to be offended. There are hundreds of us here. A few have thin skins. It's really hard trying to 'elmer' new hams via email and mail lists even if everybody uses the same language. We don't. I'm trying to help and nothing is off limits. Real questions here or in private are welcome. Flames will get you membership in my bit bucket.

73,

Bill KU8H

On 12/6/18 3:14 AM, iz oos wrote:
I don't have a bitx40, but seems you should set BFO further in a way you have only the 500-2500hz bandpass.
Il 06/dic/2018 01:50, <joshuaclough4@... <mailto:joshuaclough4@...>> ha scritto:
My SDR shows my BITX40 signal looking more like AM. Has the carrier
and USB when it should not. The USB does look weaker than the LSB
that's actually supposed to be there, but still way too strong.
I've tried adjusting the two pots thinking that something was
overdriving the signal to create this, but those in any combination
don't seem to change the sideband supression (or lack there of).
I even tried changing the raduino sketch (which being evidently a
clone was fun in itself) without any change.
I've previously tested a lot of stuff already on the board because
It stopped transmitting before and stuff tested fine, which drove me
nuts. Eventually figured out it was the incompatible microphone type
I had hooked up. Had simultaneously changed the power supply and
thought that had damaged something and never thought about the mic.

--
bark less - wag more

I don't have a bitx40, but seems you should set BFO further in a way you have only the 500-2500hz bandpass.
Il 06/dic/2018 01:50, <joshuaclough4@... <mailto:joshuaclough4@...>> ha scritto:
My SDR shows my BITX40 signal looking more like AM. Has the carrier
and USB when it should not. The USB does look weaker than the LSB
that's actually supposed to be there, but still way too strong.
I've tried adjusting the two pots thinking that something was
overdriving the signal to create this, but those in any combination
don't seem to change the sideband supression (or lack there of).
I even tried changing the raduino sketch (which being evidently a
clone was fun in itself) without any change.
I've previously tested a lot of stuff already on the board because
It stopped transmitting before and stuff tested fine, which drove me
nuts. Eventually figured out it was the incompatible microphone type
I had hooked up. Had simultaneously changed the power supply and
thought that had damaged something and never thought about the mic.

Respectfully, the point of being a ham is to learn about electronics and RF.? The point of the BITX radios is that we have a base radio to mod and explore and learn from/with.? Toroids are really easy to wind - and Farhan's latest mod was developed specifically because there's nothing critical.? It's easy to build, easy to install, and doesn't require a spectrum analyzer to align.

As for the relays:? I'm guessing anyone that can read in any language can pattern match 'Virtual' and "Axicom" and understand that if their radio doesn't have Virtual relays that it's been upgraded.? We've been photographing the boards, comparing schematics, and noting differences since the BITX40s started to ship - we'll know when it's updated (and Farhan's already stated that the relays have been updated).

Questions from folks are good - we should be encouraging them!? Answers from folks that grok more fully is called leadership.? Calling new hams 'clueless' is not useful.

73, Andy, KG5RKP

My point is, most readers of the forum have no idea how to proceed.
Having three different vaguely described fixes is not quite putting this to bed.

We should have a good simple recommeded fix, probably based on Farhan's recommendations in your link:?
? ? /g/BITX20/topic/28088828#61869

Should describe exactly what parts are used and show exactly how to install them.
Instructions that are complete enough that somebody having trouble relating schematic to board can complete it.
And the fix should be verified by somebody with a spectrum analyzer.

We have no idea with what mods a uBitx from HFSignals will currently have.
Or how to tell a production board with good relays (if such exists) from one with bad relays.?

If this does not get nailed down, we will have thousands of posts here from
somewhat clueless uBitx owners wondering if they will get thrown in jail for operating their uBitx.
(Nobody has yet reported any such trouble.? And there are several thousand unmodded uBitx's out there.)

I'd say it's fair enough to call the current situation "absurd".
No way to run a railroad,

Jerry

Andy wrote:
>? Farhan has solved the spur problem twice, possibly three times.?
>? As it appears to actually have been resolved, and as Farhan has confirmed
>? that production is updated? as fixes are identified,
>? I'd have to see a board delivered without fixes to agree that it's 'absurd'.

Andy, KG5RKP

Have you seen QST’s review of the BitX40? Seemed to pass their analysis.?
I think that was with an unmodded radio.?

Guy WB7SZI?

I've tried adjusting the two pots thinking that something was overdriving the signal to create this, but those in any combination don't seem to change the sideband supression (or lack there of).