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With two ( the same preferably) and a phaser unit one can do some interesting things..

Ideally not using mla30’s but better units.

Thanks.? However, I have the dx, not the duo.? It is interesting, though, what two receivers can do with "diversity."
My question pertained to two antennas, not two receivers.
I guess the point is that with two ANTENNAS, we can MANUALLY achieve similar results by playing with the positioning of the antennas, correct?

Yes. To get an idea of what is possible, watch this video...

https://youtu.be/x1DRgprcC6g

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And happy new year ( almost) to you too

(By the way, that link you included has a good few errors, first main one the vert radiation pattern..( far far too optimistic, they have same rad pattern as rx loop, ie cloud warmer ( yes you CAN work dx, as I do) …then the over voltage arc “ spots” on russian vac caps ( they come new like that..))

Simon g0zen

Happy new year !
--https://www.nonstopsystems.com/radio/frank_radio_antenna_magloop.htm

Thanks Steve M0ZEH

On 12/29/2022 7:14 AM, Jeff Green wrote:

NASA: Split Lock Washers Are "Useless"!

Many years I ago I worked at NASA building space flight hardware. This hardware was launched on the Shuttle, so it had to withstand Shuttle launch vibration. It was installed on the International Space Station and needed to last for years...so it was built (overbuilt?) to a very high standard.

I can't recall a single instance of our hardware using any form of locking washer - split, star, interference, or friction-locking (Nylock). Everything used locking Helicoil (or similar) threaded inserts or some form of thread-locking compound like Loctite or Vibra-tite.

In my current career in military aviation, I've seen split lockwashers on MANY pieces of aircraft avionics. Some of the gear I've handled went thru MIL-STD-810 qualification for vibration... Some of the gear I've handled was been literally back from a warzone. I've never seen loose hardware due to a locking washer failure. (Now, I have seen split washers literally split in half upon removal on some vintage WWII gear I've worked on...)

That said, all of the important stuff like driveshaft bolts, etc., use locking methods that are much more robust than split washers. :)

I think the bottom line is to think about what you're doing and the severity of the failure. For our ham-radio stuff, split washers are fine. For a turbine engine fuel control, it's not. For something going to space, it's not.

thanks much and 73,
ben, kd5byb

"The Nylock nuts are very good for moderate temperature applications."

My rule of thumb is "people temperatures", and no Sun.

I've had the insert crack due to cold, and UV, on very rare occasion fall out, or migrate and open up in the heat, to the point one can spin a nyloc almost as easily as a standard nut.

I don't like split or star lock washers because they shred whatever they touch, the split washers even worse, often scything off metal, leaving gouges, ridges, burrs, and debris long before torque spec is reached.

Truly horrific things.

I like Hex Flange Lock Nuts, as shown here:



They come in various grades, and materials, they hold, and the flange spreads out the holding pressure, important in some applications.

You can see an example of a flanged hex lock nut application in the attached image of a pair of guy brackets I made. The nylocs, by the way, also have a drop of loctite, just to be safe.

Kurt

Hi Marcus,

OK all understood.

I also use the same network with a Skanti Marine HF transceiver.

The receiver was intended to be used with separate TX and RX antennas. Probably just a 12ft whip on RX, as a result it has far too much gain on the LF bands and needs some attenuation, and not quite enough on the upper HF bands, so it needs the pre-amp on.

Same with the original SDR Play RSP1, which had no pre-amp gain control. it was either vastly overloaded or deaf as a post.

By using the equalisation network, I can leave the pre-amp on and it all works fine.

Good luck,

Martin

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Thanks Martin;

Here in SA we don't have the BC overloading below 10MHz. Several MW stations was turned off last 2 or 3 years so I even removed a 4 frequencies MW BC trap I did for a KiWi that shares my antennas (mini whips, mag loops etc). I recalculated the resistive att for 20dB and will check the freq response with a NanoVNA.

OT: This pre-emphasis network will be used in a different and even silly app: to solve some design issues on an old HF transceiver I use, where below 10MHz I often use it with the built in 20dB attenuator engaged. And above 10...12MHz no attenuation at all. At the same time a 500Hz CW filter introduces some extra 6 to 8dB attenuation, which is "too much" on the silent bands. So I built a generic RF LNA with an ERA6 I had, inserted this pre-amp before the front end and adjusted the receiver overall gain again. Until now vy good results on higher bands but of course I still use 20dB internal attenuator on 7MHz and below. This network will be placed after the preamp to keep system noise as low as possible (I live at a rural area so still a low noise neighborhood). Before the pre-amp still the original low pass filters or MW high pass anyway, so pre amp only sees 5MHz of HF spectrum. Let's test it.

73
Marcus

On Fri, Dec 30, 2022 at 11:31 AM, Marcus Ramos wrote:

That's it! Thanks!

No problem.

The amount of attenuation, and the curve that it follows, generally needs to be adjusted to suit the antenna in use. But the values I have shown tend to be a good compromise and will usually reduce the most severe overloading from strong broadcast stations on frequencies <10MHz, which tend to be particularly problematic in Europe during the early evening and at night .

Let me know if you need any further help.

Regards,

Martin

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That's it! Thanks!

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I went there late in the night but will try again. Thanks.

Try this thread.

/g/loopantennas/message/16088

Regards,

Martin

Martin has an extensive website..try on there..

Type in call sign you should find it.

Hi Tom,

sorry to correct you, aircraft use a lot of split ring lock washers, and I mean a lot!

I have over four decades of avionics experience behind me. There are many places on modern aircraft where they are not used, even more places where they should not be used (some units and antenna that come with mounting hardware are likely to use them). Interestingly, terminal strips in our 1941 Curtiss C46 Commando used fibre lock nuts, while decades newer aircraft may have terminal strips with plain nuts, flat washers, and split ring washers. Many electrical contactors use plain nuts with split ring washers, take a look at the alternator, master contactor, or starter contactor on an aircraft.

Ron VE8RT (employer's website www.buffaloairways.com )

On Thu, 29 Dec 2022 17:00:32 -0800
"Tom Seeger" <thomas.b.seeger@...> wrote:

You wont find any of those split lock washers on airplanes or aircraft engines, because they are useless. They mainly use elliptical offset nuts, often called jet nuts or aircraft nuts. The Nylock nuts are very good for moderate temperature applications.

--
Ron VE8RT <ve8rt@...>

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Also most of the important bolts and screws are wire tied on aircraft.?

Hi ...

Some months ago I think a saw a msg where Martin G8JNJ described an of RLC network that creates sort of "pre-emphasis" across the HF spectrum (e.g. 3dB attenuation @ 30MHz and lets say 30dB attenuation @ 3MHz). I think that this subject was in this group.?I used the search tools with some regular expressions with no luck (rural noise, ITU noise etc).

My apologies if this msg was not posted on this group and If someone can refresh this topic I'll appreciate.

73
Marcus PY2PLL + PY3CRX