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Re: Regenerative receivers and loop antennas
I am convinced, that the greatest problem is the stability, which you can not achieve with regen.
When you receive SSB or CW, even some better commercial receivers (such as SONY ICF 7600) are problematic. They do have a simple BFO, and their stability is not superb and the injection locking to strong received signal could be observed.
I recommend you to play with direct conversion receiver, which uses XTAL, Ceramic resonator (7.02MHz was a frequency for satellite) or use some DDS or PLL synthesized LO. Maybe some ultrastable VCO such as VACKAR could be used too, but due to the complexity and a need for isolation it looses the simplicity, which you are (most probably) searching for.
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Re: Regenerative receivers and loop antennas
Regens are just fun.? What other total receiver can offer demod of AM, CW, SSB, and FM in a pinch through slope detection with a single active device?!? Sure, they're finicky, but perfect for us old fossils who like to tweek knobs.???
On Wed, Feb 8, 2023 at 10:12 PM Andrew Russell < vk5zuc@...> wrote:
Good question Ottavio,
The thing that comes to mind is that with regens strong signals can injection lock the oscillator. Feature or bug depends on usage. Good?for AM usually but not for CW or SSB.
Andrew VK5CV.
A few days ago, I sent this message to [email protected]:
On Mon, 30 Jan 2023 at 15:41, Ottavio Caruso wrote:
>
> Please forgive my naive question.
>
> I live in a ground floor concrete apartment in urban UK. Long story
> short, no legal chance to erect antennas here. My only option is to
> wire some loop somewhere (possibly outside around the window frame).
> My goal is to listen to CW on the 40, 30 or 20 metres.
>
> I remember reading a few years ago that regens work better (or only?)
> with (random?) long wires and a good earth. This is not feasible for
> me; on top of that this is an old-ish Council estate built with crap
> materials and I don't trust the earth going to plumbing and radiators.
>
> The billion dollar question is: Do regens and loops get along with each other?
I must assume that none of you is on that mailing list, so this is a
summary of the replies I got:
> A loop aerial/antenna can work fine with a regen BUT not as part of the detector tuned circuit.? Use it as the source for a simple RF stage and then couple that quite lightly to the detector.
> .....a loop as the inductor of a regen (especially one oscillating for CW reception) is really a recipe for dissatisfaction with the receiver.? ?eceive frequency will be unstable in more than way!
Now, I know this is true, but why? Bear in mind my electronics
knowledge is limited to passing the amateur radio exam, so some
rudiments of theory and very little practice.
What is so bad with either loops and/or regenerative receivers that
they are a "recipe for dissatisfaction"?
--
Ottavio Caruso M0TTV
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
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Re: Regenerative receivers and loop antennas
Good question Ottavio,
The thing that comes to mind is that with regens strong signals can injection lock the oscillator. Feature or bug depends on usage. Good?for AM usually but not for CW or SSB.
Andrew VK5CV.
toggle quoted message
Show quoted text
A few days ago, I sent this message to [email protected]:
On Mon, 30 Jan 2023 at 15:41, Ottavio Caruso wrote:
>
> Please forgive my naive question.
>
> I live in a ground floor concrete apartment in urban UK. Long story
> short, no legal chance to erect antennas here. My only option is to
> wire some loop somewhere (possibly outside around the window frame).
> My goal is to listen to CW on the 40, 30 or 20 metres.
>
> I remember reading a few years ago that regens work better (or only?)
> with (random?) long wires and a good earth. This is not feasible for
> me; on top of that this is an old-ish Council estate built with crap
> materials and I don't trust the earth going to plumbing and radiators.
>
> The billion dollar question is: Do regens and loops get along with each other?
I must assume that none of you is on that mailing list, so this is a
summary of the replies I got:
> A loop aerial/antenna can work fine with a regen BUT not as part of the detector tuned circuit.? Use it as the source for a simple RF stage and then couple that quite lightly to the detector.
> .....a loop as the inductor of a regen (especially one oscillating for CW reception) is really a recipe for dissatisfaction with the receiver.? ?eceive frequency will be unstable in more than way!
Now, I know this is true, but why? Bear in mind my electronics
knowledge is limited to passing the amateur radio exam, so some
rudiments of theory and very little practice.
What is so bad with either loops and/or regenerative receivers that
they are a "recipe for dissatisfaction"?
--
Ottavio Caruso M0TTV
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
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Regenerative receivers and loop antennas
A few days ago, I sent this message to [email protected]: On Mon, 30 Jan 2023 at 15:41, Ottavio Caruso wrote:
Please forgive my naive question.
I live in a ground floor concrete apartment in urban UK. Long story
short, no legal chance to erect antennas here. My only option is to
wire some loop somewhere (possibly outside around the window frame).
My goal is to listen to CW on the 40, 30 or 20 metres.
I remember reading a few years ago that regens work better (or only?)
with (random?) long wires and a good earth. This is not feasible for
me; on top of that this is an old-ish Council estate built with crap
materials and I don't trust the earth going to plumbing and radiators.
The billion dollar question is: Do regens and loops get along with each other?
I must assume that none of you is on that mailing list, so this is a summary of the replies I got: A loop aerial/antenna can work fine with a regen BUT not as part of the detector tuned circuit. Use it as the source for a simple RF stage and then couple that quite lightly to the detector. .....a loop as the inductor of a regen (especially one oscillating for CW reception) is really a recipe for dissatisfaction with the receiver. ?eceive frequency will be unstable in more than way! Now, I know this is true, but why? Bear in mind my electronics knowledge is limited to passing the amateur radio exam, so some rudiments of theory and very little practice. What is so bad with either loops and/or regenerative receivers that they are a "recipe for dissatisfaction"? -- Ottavio Caruso M0TTV A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?
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LZ1AQ loop amplifier boards for sale
I had a hole in my schedule and had time to build 4 more LZ1AQ loop amps to sell. If any one is interest please contact me off list at everettsharp (at) aol? com
?
Everett N4CY
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LZ1AQ Loop Amps for sale All SOLD
Guys,
All of the LZ1AQ loop amps have sold..I will build more in a a couple weeks, or so
Everett N4CY?
Awhile back I said I was not going to build any more of the LZ1AQ loop amps. However, I continue to get request for them, so I had another batch of boards made and built up four of them using all SMD parts.,one of the boards have been sold, so there are 3 left.
?
If any one is interested please contact me off list at Everettsharp (at) aol com.
?
Everett N4CY
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LZ1AQ Loop Amps for sale
Awhile back I said I was not going to build any more of the LZ1AQ loop amps. However, I continue to get request for them, so I had another batch of boards made and built up four of them using all SMD parts.,one of the boards have been sold, so there are 3 left.
?
If any one is interested please contact me off list at Everettsharp (at) aol com.
?
Everett N4CY
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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.
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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?
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Yes. To get an idea of what is possible, watch this video...
https://youtu.be/x1DRgprcC6g
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I have 2 MLA-30 receive antennas.
Is there any configuration that would enhance reception by combining them, e.g. by using a splitter in reverse (combiner)?
Either 90 degrees to each other or parallel to each other in close proximity or spaced?
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Re: Loop design website
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
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Happy new year !
--https://www.nonstopsystems.com/radio/frank_radio_antenna_magloop.htm
Thanks Steve M0ZEH
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Re: NASA: Split Lock Washers Are "Useless"!
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
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Re: NASA: Split Lock Washers Are "Useless"!
"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
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Re: RLC Network for ITU noise curves compensation
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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Re: RLC Network for ITU noise curves compensation
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
Em 30/12/2022 08:50, Martin via
groups.io escreveu:
toggle quoted message
Show quoted text
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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Re: RLC Network for ITU noise curves compensation
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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Re: RLC Network for ITU noise curves compensation
I went there late in the night but will try
again. Thanks.
Em 30/12/2022 07:12, Simon escreveu:
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Martin has an extensive website..try on there..
Type in call sign you should find it.
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Everett N4CY
Radioman ZeroZero
Ben Hall
Marcus PY2PLL PY3CRX