On Sun, Jan 14, 2018 at 01:09 pm, Andy G0FTD wrote:

True Blue seems to have rather quiet.

I don't know what you're on about, but if you have some problem with me, why don't you deal with it like a grownup and send me private mail explaining what's wrong.? OK?? Cool.

In the meantime, here's my reply I spent all afternoon reformatting offline, which was why I was so mysteriously "quiet":

On Fri, Jan 12, 2018 at 05:20 pm, Alan de G1FXB wrote:

>> TrueBlue wrote:

>> I'm sort of curious how 3xBS170=200mW on 40m at 9V.? That's
>> about what you should get from one BS170 at ~5v on 40m.

>

But that still doesn't explain why more voltage and more transistors,
both, wouldn't increase output.? According to this ^, it should.

> Hans spent some time writing up the theory of parallel operation.

??? "There are always minor variations between device characteristics
from one transistor to the next. If these were bipolar NPN transistors,
we would not be able to parallel them in this way. If one transistor
takes more of the load and starts to heat up, its resistance further
decreases and this causes it to get even hotter. This process is known
as “thermal runaway” and results (quickly) in destruction of the
transistor. Emitter resistors are used to help balance the load. But
with MOSFETs, their resistance INCREASES as the temperature goes up – so
there is an inherent self-balancing when multiple devices are used in
parallel, without any need for additional balancing resistors which
would increase component count and waste some power."

This is nice to see, as there have been many dozen prior posts on this
board (and elsewhere) about the necessity for matching these BS170
transistors in this specific use.? I'm glad I haven't wasted even more
time and money in that pursuit.? I was >< this close to building a
MOSFET comparator for the task.? Misinformation is murder.

> if you are using the U3S as the driver then get that sorted first.

I'm OK on the U3Ss.? The build on mine was 100% without problems from
first power-up -- it's a bone-simple kit and I have good skills.? The
problems I did have (and there were many) were purely from misinformation
from a surprising range of sources.

> if you have limited access to test equipment...

Strangely, my expenditures on test and bench equipment have exceeded
those on actual radio gear by a factor of about 8:1, most notably on a
new oscilloscope that I was urgently persuaded to buy and have never
used once in the eight months or so that I've had it, aside from zeroing
the leads and testing its self-calibration.

> perhaps buddy up with an elmer or find somebody at a local club

I just let a membership expire on 1 January from what I believe is the
largest club in my area.? They offer a free calendar year's membership
to new licensees (I passed Tech and General on the same day).? I didn't
find membership productive.? My thoughts on this are another post.

> There is a lot of info on the PA web page, build manual & App notes,
> but the info you need is there.

It is really interesting.? The initial part on the tech background of
the design is mostly over my head and not of practical use, but the
actual construction and testing section is excellent.

> The aim is to minimise temperature change and loading to the 27MHz
> crystal reference and to a lesser extent the Si5351 IC during
> the WSPR or more demanding QRSS TX cycle

> The black art of Park Modes, expect to have to experiment. Everybody's
> unit will have a different spread of tolerances , what works for one
> may may make it worse on another.

> The long TX cycles of QRSS is the most demanding mode, if you believe
> you have a problem, get yourself seen on a local QRSS grabber. You can
> see any changes in real time(ish) and have a feel what is making
> things better or worse.

There's only one grabber in the western US, which never picked me up in
that NYD QRSS thing anyway.? However, I did monitor my own TX and it
showed a very linear (if small) drift over a ~7min. TX, consistent with
crystal heat-up.

Many another QRSS transmission I saw on the grabber pages described the
trajectory of a beanbag tossed by a toddler.? I was amazed.

[But QRSS is over in the US, as is every other mode in the (currently
full) U3S firmware except WSPR and CW.? There's no point beaconing
signals with no one listening -- and they aren't.? Even the most recent
modes are essentially history.? I went from at least fifteen JT65 spots
a day to one or two, and two or three JT9 spots a day to that many in a
month.? Even WSPR is dropping off, it seems.

Hans really needs to provide some of these graveyard modes in the U3S
with the solemn offices of Christian burial and free up some firmware room for
FT8 and future modes that bear some interest.

The object in propagation beaconing is to get the absolute maximum
possible number of spots to see some patterning, and you can't do that
with dud modes.? I also think that a faster mode should provide more spots
during marginal propagation.? The current ubiquity and speed of FT8
seem to be ideal.]

>> (b) causing it to cool down.? Huh?

> You are thinking about, Han's solution of gluing a coin or other
> people have reported attaching a stick on heatsink to the crystal?

> The aim IS NOT to cool the crystal but to add a thermal? mass to it,
> to again trying to delay short term temperature changes.

Now, this actually makes sense - but there are dozens of misinformed
posts here on the subject that refer to using heatsinks on the crystals.
?Heatsinks are not there to provide "thermal mass" (interesting turn of
phrase), but to defeat thermal mass, i.e., to cool.? Thus my confusion.
Thanks for clearing that up.

> A mild steel nut would be my preference over a piece of aluminium,
> but anything that slows the temperature change works....

I think if I were convinced that this was a problem for me, I would just
wall-in the module and fill it with spray can expanding foam insulation.
I doubt one could improve on that.

>> In any case, as I understand it, if you don't drift beyond +/-4, it
>> doesn't make any difference anyway.? The default setting gives me as
>> close to zero drift as external conditions will ever permit

Once again, I'm still not understanding the quest for zero drift, at least with
WSPR.?

> a good power supply is equally required for the standard version.

[...]

> (In particular, decoupling capacitors around the Voltage Regulators,
> mounted as close as you can to the device legs.? As well as hopefully
> decoupling RF, and general hash they prevent parasitic oscillation
> that affects regulators under some load conditions.)

My voltage stability is absolutely rock-solid.? As to noise, I can't
say, but I could probably measure it with my (unused) oscilloscope if
knew how.? I'm unclear on the effects of noise on WSPR and the JT/FT modes.

Bill NZ0T,
Now that makes sense.
QCX,U3S,balloon flights..etc..separate sub topics rather than blended all together....good idea.
Jim

:-/

On a whim I replaced the ?P with one from another kit (never been set up). Set it to 80m, went to alignment, selected peak Bandpass, the reading was 5. C1 doesn't change it... Swapped the old ?P back in and the reading was 3 and C1 doesn't affect it. It was 2 when I started swapping ?P...?
--
73
NE5U

Mike

T1 is rewound and installed. There is no change in the bandpass peaking. C1 makes no difference. Peak value is 2 and about 3/4 of the bars.
--
73
NE5U

Mike

开云体育

Thank you Slim, you "get it".

John Mazzone

Thank you all for your quick responses and tips. I am going to hold the coffee (and beer) and give it a shot! I'll report back!

Thanks!

Ron, AL7JR

QCX 40 T1 wound ok after I figured out which ends of the wires went in which holes, so they would just drop right in. My problem came from not RTFM and leaving a longer loop on the windings. If I had to do it over again I would leave a longer loop, and melt the insulation off after passing through hole. Testing the solder and not the wire for continuity works well.

Don WB9STS

开云体育

Do you feel better now?? Just saying.

Lee, w0vt

?

True Blue seems to have rather quiet.

Maybe he's keen not to let us know he's really John KM6HUV, who also posts as Hazada Masklo.

I wonder who he'll be next week ? ;-)

73 de Andy

开云体育

I find it very strange that a member of this group is hiding behind a nickname and won’t post his (or her) callsign. ?I specifically asked what it was when the New Year QRSS Party happened but nothing was forthcoming.

--
QSO365 - My amateur radio blog:?

?

Take a look at how the Elecraft message board is organized.? It's all one group but there are several sub-groups suck as K3, K2, QRO, for different products.? Works great.

73,Bill NZ0T

It's easy to always a toroid in the same sense.? I always stick the wire through the toroid towards me and then start winding to the left side of that first wire.? On could do it the other way too.? Just be consistent in how you start. And, as suggested above take a look at how the holes in the PCB are oriented soyou know which way to start.?

73, Bill NZ0T

On Sun, Jan 14, 2018 at 11:42 am, TrueBlue wrote:

I've been licensed for almost a year,

Since you've never published your callsign - how would we know ?