Re: FS:Sota Beams Variable Filter Break-out
This is used with the Sotabeams LaserBeam Dual variable kit. I didn't like the limited mounting options or the point-to-point of the filter kit so I made this board for my projects and had a few left over. -- David
?N8DAH
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The AGC writeup does mention that the RF gain control is assumed,
but the diagram just says "To K3 pin 14" where I assume it should say "To Wiper of RF Gain Pot"
? ??
Better yet, include the pot in the drawing.
Perhaps it should also mention the need for static discharge.
Regardless, by all accounts, that's looking like a simple and effective AGC implementation.
We get lots of thunderstorms blowing through, and I generally just try to unplug antennas
when I see them coming.? I believe I recall reading once that simply using coax offers adequate protection
if you give the braid a good earth ground.? Not sure how bulletproof that is, but my braid does have
a good earth ground.?
On p48 of July 2002 QST, it recommends something like this device:
? ??
which costs more than a Bitx40.? Is there a cheaper alternative?
Gas discharge tubes (GDT's) are often used for lightning protection on phone lines.
Seem to be available with capacitances down to? 5pf, so should work at RF.
? ??
Might well be what's in that device above.
Perhaps there's also a fuse of some sort between the antenna wire and the GDT?
Back 50 years ago, they recommended building a spark gap for use as a lightning arrestor,
the older hams who wrote about it probably had fond memories of spark gaps.
Basically a homemade GDT, using locally available air instead of some exotic gas.
Anybody know what works?
Protection schemes for this sort of thing are inherently dangerous as they are generally
untested and might give a false sense of security.? Consequences can be considerable.
Unplugging antennas is still a good idea, will still have a rig if the house doesn't burn down.
Jerry, KE7ER
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On Fri, Apr 20, 2018 at 03:07 pm, Don, ND6T wrote:
The principle idea of my AGC mod is built around the potentiometer RF gain control. It is meant to work in concert with it. As such, that potentiometer works as a static dissipation device to ground. My antennas here are both end-fed random wires (one 175 feet long, the far end up 100 feet) and are excellent static accumulators unless provided a path to ground. A 10 Megohm resistor will do that, by the way. I cannot overemphasize the desirability of a manual RF gain control, even with an AGC. I think most operators, even with the fanciest of rigs, use that control extensively. Best noise reduction device ever! 73, Don?
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Chris:
The parts caps I have are smaller then the resistors on the board,
I think they resistors are 0805.
It is not too difficult to solder one on top of the other.
Electrically, it doesn't matter what the size is. The inductor can
be any size, as there is no pad to fit it on, you stand it up, so
0805 is a good choice. Of course, there is nothing stopping you
from uses leaded parts.
Howard
On 4/20/2018 7:14 PM, Chris Clarke wrote:
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Howard
I don't normally do SMD but this sounds like a good idea ... I'll
need to order some for this side of the pond, but which physical
SMD sizes are these components?
73 Chris
G3SQU
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Howard
I don't normally do SMD but this sounds like a good idea ... I'll need to order some for this side of the pond, but which physical SMD sizes are these components?
73 Chris
G3SQU
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Re: anybody tried softrock and hdsdr with Ubitx?
On Friday, April 20, 2018, 6:07:46 PM CDT, John <vk2eta@...> wrote:
Detailed instructions how to connect SDR here:?
73, John (VK2ETA)
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Re: anybody tried softrock and hdsdr with Ubitx?
Detailed instructions how to connect SDR here:?
73, John (VK2ETA)
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Congratulations!? I just ordered one on 18/4/2018, so probably have another month to wait.
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Don't let it get to that potential. If you are talking about lightning and such, yes, short it to ground outside. I am referring to those gentle breezes and what I call static charges. Nothing major, just enough to be annoying. -Don
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That is not where you want static charges dissipating! Chokes to ground, resistors, at the antenna. All a better place for it (the fire) to happen.
Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ
Owner - Operator
Big Signal Ranch ¨C K9ZC
Staunton, Illinois
Owner ¨C Operator
Villa Grand Piton ¨C J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!
Moderator ¨C North American QRO Group at Groups.IO.
email: bill@...
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Tim Gorman Sent: Friday, April 20, 2018 4:05 PM To: [email protected]Subject: Re: [BITX20] receiver overload I'm sure it happens. But not consistently. You need wind and something to create the charge like blowing dust. If the tuner is dissipating the charge why doesn't the rig itself do it, at least with an unbalanced feed? tim ab0wr On Fri, 20 Apr 2018 08:47:00 -0500 "K9HZ" <bill@...> wrote: Unless the antenna is picking up a static charge and the antenna tuner
is acting like an impedance to ground draining that charge
off. Don't laugh, it happens.
Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ
Owner - Operator
Big Signal Ranch ¨C K9ZC
Staunton, Illinois
Owner ¨C Operator
Villa Grand Piton ¨C J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!
Moderator ¨C North American QRO Group at Groups.IO.
email: bill@...
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 8:42 AM
To: [email protected]
Subject: Re: [BITX20] receiver overload
Usually a tuner will increase noise, at least atmospheric noise, as
the tuner creates a match between the receiver and the antenna. A
matched antenna shouldn't "tame" the noise. If that is actually
happening then a closer look at the system might be appropriate.
tim ab0wr
On Fri, 20 Apr 2018 11:39:39 +1000
"John Sharpe" <johsharpe@...> wrote:
Hi all,
I just had a thought about new users of the uBitx and the Bitx40.
I have both of these fine rigs but with my good antenna - a ZS6BKW
<> at 30
feet
- the receivers are swamped by noise and big signals on 40 metres.
When I tested just now a 59+ 10 signal on my IC-7300 was unreadable
on the Bitexes with the big antenna (which has a low SWR at 40
metres) because of noise. With an antenna of just 6 feet of wire in
the shack the signal was readable (but weak) on the Bitexes!
I usually use a tuner beween the antenna and the Bitexes - that
works fine to tame the noise. Also I have fitted an RF control to
the Bitx40 that helps quieten big signals.
But if you have lots of noise in the receiver and no tuner - try a
smaller antenna on receive (it will be no good for transmitting). If
that improves things maybe you need a tuner or an RF control.
73s John V2VOL
---
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|
Re: Transmit indicator light.
In my opinion, the very best LED transmit indicator was the one that Derry Spittle (VE7QK [SK]) used in his Epiphyte QRP SSB series. That was just a 470 ohm quarter watt resistor through a small toroid and attached to a panel-mounted LED at each leg. The lead to the antenna passed through next to that resistor. That was it! When RF went to the antenna, it lit. You could easily tell if you were speaking loudly enough into the microphone, etc. Fast response, little panel space, and EASY. 73, Don
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The principle idea of my AGC mod is built around the potentiometer RF gain control. It is meant to work in concert with it. As such, that potentiometer works as a static dissipation device to ground. My antennas here are both end-fed random wires (one 175 feet long, the far end up 100 feet) and are excellent static accumulators unless provided a path to ground. A 10 Megohm resistor will do that, by the way. I cannot overemphasize the desirability of a manual RF gain control, even with an AGC. I think most operators, even with the fanciest of rigs, use that control extensively. Best noise reduction device ever! 73, Don?
|
Re: uBitX with CAT control and Split operation?
Hello
Thanks ? Best Regards, LB3RE K3RAG? Skype: lb3re.rag
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Ian's software will do both.
Do a search on KD8CEC on this forum, or?see?.
73, John
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The stock uBitx provides a DC path to ground.
During receive, that would be K3-12,14, K1-12,14, L1,2,3,4,? and T2.
Don's AGC fix adds AC coupling, there is no DC path:
? ??
Perhaps a 1k resistor from antenna to ground is in order there.
Jerry
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On Fri, Apr 20, 2018 at 02:04 pm, Tim Gorman wrote:
I'm sure it happens. But not consistently. You need wind and something
to create the charge like blowing dust. If the tuner is dissipating the
charge why doesn't the rig itself do it, at least with an unbalanced
feed?
tim ab0wr
. . .
?
On Fri, 20 Apr 2018 08:47:00 -0500 "K9HZ" < @Doc_Bill> wrote:
Unless the antenna is picking up a static charge and the antenna
tuner is acting like an impedance to ground draining that charge
off. Don't laugh, it happens.
|
Re: uBitX with CAT control and Split operation?
Ian's software will do both.
Do a search on KD8CEC on this forum, or?see?.
73, John
|
I'm sure it happens. But not consistently. You need wind and something to create the charge like blowing dust. If the tuner is dissipating the charge why doesn't the rig itself do it, at least with an unbalanced feed? tim ab0wr On Fri, 20 Apr 2018 08:47:00 -0500 "K9HZ" <bill@...> wrote: Unless the antenna is picking up a static charge and the antenna
tuner is acting like an impedance to ground draining that charge
off. Don't laugh, it happens.
Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ
Owner - Operator
Big Signal Ranch ¨C K9ZC
Staunton, Illinois
Owner ¨C Operator
Villa Grand Piton ¨C J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!
Moderator ¨C North American QRO Group at Groups.IO.
email:? bill@...
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 8:42 AM
To: [email protected]
Subject: Re: [BITX20] receiver overload
Usually a tuner will increase noise, at least atmospheric noise, as
the tuner creates a match between the receiver and the antenna. A
matched antenna shouldn't "tame" the noise. If that is actually
happening then a closer look at the system might be appropriate.
tim ab0wr
On Fri, 20 Apr 2018 11:39:39 +1000
"John Sharpe" <johsharpe@...> wrote:
Hi all,
I just had a thought about new users of the uBitx and the Bitx40.
I have both of these fine rigs but with my good antenna - a ZS6BKW
<> at 30
feet
- the receivers are swamped by noise and big signals on 40 metres.
When I tested just now a 59+ 10 signal on my IC-7300 was unreadable
on the Bitexes with the big antenna (which has a low SWR at 40
metres) because of noise. With an antenna of just 6 feet of wire in
the shack the signal was readable (but weak) on the Bitexes!
I usually use a tuner beween the antenna and the Bitexes - that
works fine to tame the noise. Also I have fitted an RF control to
the Bitx40 that helps quieten big signals.
But if you have lots of noise in the receiver and no tuner - try a
smaller antenna on receive (it will be no good for transmitting). If
that improves things maybe you need a tuner or an RF control.
73s John V2VOL
---
This email has been checked for viruses by AVG.
|
I used an old Motorola hand mic. I just packed the electret element with a piece of acoustic foam in front and enough behind it to hold it place with the back on. Works fine. tim ab0wer On Fri, 20 Apr 2018 10:54:32 -0700 "Nelson" <ngtdlt@...> wrote: Sorry, I meant to show a picture of the front of the completed mic
also...
On Fri, Apr 20, 2018 at 10:46 AM, Nelson <ngtdlt@...> wrote:
I used an old Regency CB mic case, removed the old mic element, cut
down a small plastic funnel to fit where the original mic element
went and cut the other end of the funnel at appoint where a Radio
Shack electret mic element would just fit and hot glued the whole
mess together.
On Fri, Apr 20, 2018 at 8:50 AM, Roy Appleton
<twelveoclockhigh@...> wrote:
?????
On Fri, Apr 20, 2018, 10:39 AM bobh_us <rwhinric@...> wrote:
My mic has its own processor
--
I always thought the Universe was a wonderfully strange place until
I studied Particle Physics - I now know the Universe is, in fact,
profoundly odd in nature
|
uBITX ordered Feb 26, received via DHL today.? Can't wait to begin!
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Here is my mic housing, I printed it up to work with the supplied parts.? The element drops in to the hole, the button snaps into the side, the three posts have holes in them to wrap the wires for stress relief.? I've also got a back printed up, but I haven't put it on the live version yet.? This was the testbed print, I ended up moving the PTT up higher and to the other side because it didn't fall under any fingers in this spot. 
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uBitX with CAT control and Split operation?
Hello
I am planning to buy/build a uBitX for dxped use.
But not sure about CAT control and VFO split ??!
Best Regards,
Stein-Roar Brobakken
post@...
LB3RE K3RAG
Skype: lb3re.rag
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Re: anybody tried softrock and hdsdr with Ubitx?
On Friday, April 20, 2018, 11:16:38 AM CDT, Ashhar Farhan <farhanbox@...> wrote:
There is am article in the swedish magazine, the QTC about using the rtl-sdr with ubitx. - f
On Thu, 19 Apr 2018, 22:20 Paul Schumacher via Groups.Io, <wnpauls= [email protected]> wrote: Has anyone tried a softrock and hdsdr with Ubitx to get the spectrum and waterfall display?? (or something similar?) If so, can you please describe how to go about doing it?
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N8DAH
Don, ND6T
K9HZ
LB3RE/LC0X "Rag" Stein-Roar
Doug K7IP
