Re: ANTUINO antenna analzer CERTAIN CLARIFICATIONS REG

Jorge Luiz Fenerich

Thanks for the lesson on antennas Peter, living and learning. Congratulations.
Jorge PY2PVT _._

Em sex., 19 de jun. de 2020 às 05:10, Peter LB0K <lb0k@...> escreveu:

Muthu - Checking antennas can be confusing.
An antenna only achieves its theoretical impedance and size when in free space, but we don't have long enough feeders for that to ever happen.
In real life we can get a close fit to the theoretical numbers when the dipole antenna is mounted at one half wavelength above ground, whatever 'ground' is. Also at one whole wavelength above ground, about 73 ohms.
One illustration is the graph of 'impedance variation at height over ground' given in the ARRL handbooks and antenna books.
In most of our real situations these sorts of spacing are very difficult to achieve, so we compromise and probably don't get them over a 1/4 wave of 10m or 5m, as in your case. Therefore the 40m section and probably the 20m sections won't achieve anything like 73ohm maybe 50ohm, or under.
These effects pull down the resonance frequency(s) but your antenna doesn't swing on 40m, nor on 20m, indicating that it is too short on both.
As G4NFR suggests make a new one say 5-10% too long, or add on short pieces to similar lengths.

As a rough starting point a 40m dipole will need about 20.5m of wire, a 20m one will need 10m.

The chosen lengths can then be adjusted by folding back the ends and taping them to the 'active portion', while you make more measurements, this way you get a good idea of how much can be easily removed before one cuts tooooo much off. Keep the lengths symmetrical.  I leave mine with a good bit folded back so that when I move the antenna it can be easily be lengthened!
One point not yet answered it that you seem to have an extra resonance in the middle, this is probably coming from one arm of the 40m dipole and an opposite arm of the 20m dipole resonating together.
But perhaps you can't get the projected length suspended above your property, don't despair, just fold the ends down or around.
If you have to cut the ends off, making it too short again, you can use an AMU (aka ATU) to achieve a match.

Now with your analyser you have an exciting time ahead seeing more of what really happens with antennas, and remember you'll see much more of the matching TO the antenna but only a little more of the matching OUT of the antenna into the æther.

Good luck!

--
73 de Jorge PY2PVT
Campinas SP
GG67MD

Re: [Antuino] An update to antuino

Ashhar Farhan

Yes, i meant the A7.

On Fri 19 Jun, 2020, 5:07 PM Dave New, N8SBE, <n8sbe@...> wrote:
"extra pin A&"

I think you meant "extra pin A7"?

73,

-- Dave, N8SBE
-------- Original Message --------
Subject: [Antuino] An update to antuino
From: "Ashhar Farhan" <farhanbox@...>
Date: Fri, June 19, 2020 6:36 am
To: Antuino@groups.io, bitx20@groups.io

I have been using thr Antuino exclusively as my main instrument for two weeks now. In the process, I have had to rewrite the entire firmware to make it more usable.
I have uploaded the new code.  I only recommend it for the fool hardy. It is available on github.com/afarhan/antuino2.2
Among the new features is continuous scanning at very fast sweeps, continuous coverage with no gaps to 250 mhz, and much simpler user interface. I have also added a voltmeter hack onto the extra pin A&. You have to add the attached circuitry to it.

Re: [Antuino] An update to antuino

Dave New, N8SBE

"extra pin A&"

I think you meant "extra pin A7"?

73,

-- Dave, N8SBE

-------- Original Message --------
Subject: [Antuino] An update to antuino
From: "Ashhar Farhan" <farhanbox@...>
Date: Fri, June 19, 2020 6:36 am
To: Antuino@groups.io, bitx20@groups.io

I have been using thr Antuino exclusively as my main instrument for two weeks now. In the process, I have had to rewrite the entire firmware to make it more usable.
I have uploaded the new code.  I only recommend it for the fool hardy. It is available on github.com/afarhan/antuino2.2
Among the new features is continuous scanning at very fast sweeps, continuous coverage with no gaps to 250 mhz, and much simpler user interface. I have also added a voltmeter hack onto the extra pin A&. You have to add the attached circuitry to it.

Re: RFI on 2 meters from uBitx

Jay - WS4JM

Thanks Everyone! Some very good information and things to try.

I have already switched to the Axicom relays, I installed my ubitx in an old Cobra 148 CB case (metal).

I will try ferrites on all of the power leads and report back.

Thanks again

Jay
WS4JM

An update to antuino

Ashhar Farhan

I have been using thr Antuino exclusively as my main instrument for two weeks now. In the process, I have had to rewrite the entire firmware to make it more usable.
I have uploaded the new code.  I only recommend it for the fool hardy. It is available on github.com/afarhan/antuino2.2
Among the new features is continuous scanning at very fast sweeps, continuous coverage with no gaps to 250 mhz, and much simpler user interface. I have also added a voltmeter hack onto the extra pin A&. You have to add the attached circuitry to it.

"sketchy"

@KF4ZGZ

So I am a total noob to arduino stuff. But I did want to upgrade the software to and upload KD8CEC sketch.
I watched Ashar's video,a few others and read a few how to and set off.
Using my newest computer, the shack desk top, I failed, several times. The IDE didn't work.
I decided to try xloader and hex. Nope, not today bobo.
So I tried my laptop. It's a good, powerful, fast laptop.
I eventually dug out my 14 yr. Dell laptop out of desperation.
I went to the IDE ... it immediately told me I need the ch340 ( or whatever the specific USB driver is) that neither new 'puter told me about.
10 minutes later my V6.1 is purring along with CEC hex loaded!
YAY ME! Another small victory!

Re: ANTUINO antenna analzer CERTAIN CLARIFICATIONS REG

Peter LB0K

Muthu - Checking antennas can be confusing.
An antenna only achieves its theoretical impedance and size when in free space, but we don't have long enough feeders for that to ever happen.
In real life we can get a close fit to the theoretical numbers when the dipole antenna is mounted at one half wavelength above ground, whatever 'ground' is. Also at one whole wavelength above ground, about 73 ohms.
One illustration is the graph of 'impedance variation at height over ground' given in the ARRL handbooks and antenna books.
In most of our real situations these sorts of spacing are very difficult to achieve, so we compromise and probably don't get them over a 1/4 wave of 10m or 5m, as in your case. Therefore the 40m section and probably the 20m sections won't achieve anything like 73ohm maybe 50ohm, or under.
These effects pull down the resonance frequency(s) but your antenna doesn't swing on 40m, nor on 20m, indicating that it is too short on both.
As G4NFR suggests make a new one say 5-10% too long, or add on short pieces to similar lengths.

As a rough starting point a 40m dipole will need about 20.5m of wire, a 20m one will need 10m.

The chosen lengths can then be adjusted by folding back the ends and taping them to the 'active portion', while you make more measurements, this way you get a good idea of how much can be easily removed before one cuts tooooo much off. Keep the lengths symmetrical.  I leave mine with a good bit folded back so that when I move the antenna it can be easily be lengthened!
One point not yet answered it that you seem to have an extra resonance in the middle, this is probably coming from one arm of the 40m dipole and an opposite arm of the 20m dipole resonating together.
But perhaps you can't get the projected length suspended above your property, don't despair, just fold the ends down or around.
If you have to cut the ends off, making it too short again, you can use an AMU (aka ATU) to achieve a match.

Now with your analyser you have an exciting time ahead seeing more of what really happens with antennas, and remember you'll see much more of the matching TO the antenna but only a little more of the matching OUT of the antenna into the æther.

Good luck!

Re: RFI on 2 meters from uBitx

MVS Sarma

Cool. Shane, concept appreciated. Congrats.

Sarma vu3zmv

On Fri, 19 Jun 2020, 5:58 am Blobby Harvey, <blobbyharvey4@...> wrote:
Hi Jay
I had the same problem RFI around 2m. I put the the bitx in a metal case and ferrite ringed the power lead.

73’s. Shane ZL2SH

On Fri, 19 Jun 2020 at 12:11 AM, Raj vu2zap <rajendrakumargg@...> wrote:
You could try replacing relays KT1/2/3 with Axicom RF relays, that should reduce this.
Check earlier posts for details.

Raj

At 18/06/2020, you wrote:
>I have been experiencing RFI on the 2 meter band when my V3 is tuned to the upper end of 75 meters. I had my uBitx tuned to the TN Phone net at 3.980 MHz and my 2 meter rig tuned to my local repeater at 146.91 MHz. The 2 meter rig showed full scale receive, with no audio. I checked with my hand held and it was full scale at least 50 feet from the uBitx. The RFI exists when the uBitx is in RX as well as TX. Seems like a 3rd harmonic of a mixing product; (45 MHz+3.98 MHz) X 3 = 146.94 MHz
>
>Any ideas where or how to add shielding or if a component needs to be replaced?
>
>Thanks,
>Jay
>WS4JM

Re: UBITX. FT8 heat sink requirements

Gordon Gibby

yes for low duty cycle modes it should work

On Jun 18, 2020, at 21:10, Dean Souleles <dsouleles@...> wrote:

﻿Hey Don - I assume your transmit duty cycle on WSPR is still10-15% which means you transmit two minutes out of 20.

You should be able to run pretty much forever at that rate.

I've run  WSPR 24 hours multiple times with stock heat sinks,

Dean
KK4DAS

Re: UBITX. FT8 heat sink requirements

Dean Souleles

Hey Don - I assume your transmit duty cycle on WSPR is still10-15% which means you transmit two minutes out of 20.

You should be able to run pretty much forever at that rate.

I've run  WSPR 24 hours multiple times with stock heat sinks,

Dean
KK4DAS

Re: RFI on 2 meters from uBitx

Blobby Harvey

Hi Jay
I had the same problem RFI around 2m. I put the the bitx in a metal case and ferrite ringed the power lead.

73’s. Shane ZL2SH

On Fri, 19 Jun 2020 at 12:11 AM, Raj vu2zap <rajendrakumargg@...> wrote:
You could try replacing relays KT1/2/3 with Axicom RF relays, that should reduce this.
Check earlier posts for details.

Raj

At 18/06/2020, you wrote:
>I have been experiencing RFI on the 2 meter band when my V3 is tuned to the upper end of 75 meters. I had my uBitx tuned to the TN Phone net at 3.980 MHz and my 2 meter rig tuned to my local repeater at 146.91 MHz. The 2 meter rig showed full scale receive, with no audio. I checked with my hand held and it was full scale at least 50 feet from the uBitx. The RFI exists when the uBitx is in RX as well as TX. Seems like a 3rd harmonic of a mixing product; (45 MHz+3.98 MHz) X 3 = 146.94 MHz
>
>Any ideas where or how to add shielding or if a component needs to be replaced?
>
>Thanks,
>Jay
>WS4JM

Re: neton screen to ver 6 board

Evan Hand

rpremooak,
That is a 2.8" Enhanced screen, so you need the files that end in _E.tft.  I do not remember where I got these from, ut here is a zip file with what I believe is the correct tft file.

73
Evan
AC9TU

Re: neton screen to ver 6 board

rpremooak@...

I attempted to use this TFT for 2.8" screen but shows as incompatible with the screen that I have which is:

# NX3224K028Do you have a TFT that is compatible with this screen?

Re: UBITX. FT8 heat sink requirements

Gordon Gibby

I doubt it seriously. Almost all Riggs, have to be Der ated a bit for continuous duty.

On Jun 18, 2020, at 17:16, Mick <Mgsebele@...> wrote:

﻿Aaron,
I run FT8 all the time without any over heat problems.
--

73
Mick VA3EPM

Re: UBITX. FT8 heat sink requirements

Mick

Aaron,
I run FT8 all the time without any over heat problems.
--

73
Mick VA3EPM

Re: Opposite side band rejection ubitx V6

Dale Parfitt

Thank you Gary,

My apologies for not doing my homework. Much appreciated.

Dale W4OP

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Gary Anderson
Sent: Thursday, June 18, 2020 3:57 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Opposite side band rejection ubitx V6

On Thu, Jun 18, 2020 at 11:38 AM, Dale Parfitt wrote:

Hi Allison et al,

Dale,
SSB filter is 200 ohms per the circuit description
https://www.hfsignals.com/index.php/ubitx-circuit-description/
Rgds,
Gary

Re: Opposite side band rejection ubitx V6

Gary Anderson

On Thu, Jun 18, 2020 at 11:38 AM, Dale Parfitt wrote:

Hi Allison et al,

Dale,
SSB filter is 200 ohms per the circuit description
https://www.hfsignals.com/index.php/ubitx-circuit-description/
Rgds,
Gary

Re: UBITX. FT8 heat sink requirements

Aaron K5ATG

I'm guessing that the uBitx V6 transistors and heat sinks are good enough for the digital modes also?
--
'72
Aaron Scott
QRPARCI# 16443
GQRP# 16389
4SQRP # 1080

Re: Opposite side band rejection ubitx V6

Dale Parfitt

Hi Allison et al,

Dale W4OP

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of barry halterman
Sent: Thursday, June 18, 2020 2:29 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Opposite side band rejection ubitx V6

Allison, as always, appreciate your input. I have noticed that between my V4 and V6 there seems to be a noticable difference. The V4 tends to be better. I might try the grounding of the cases or change the termination caps to 100pf in my V6.

Thanks

Barry

K3bo

On Thu, Jun 18, 2020, 1:24 PM ajparent1/kb1gmx <kb1gmx@...> wrote:

I got to play with a bunch of them last year and the result...

The filters vary enough that a good one can easily exceed 40db and the
average was 35db.  One I hand optimized the filter did hit 45dB.

Overall of the filters seems rather narrow and those I measured were
under 2.1KHz wide A wider 2.4 to 2.7 KHz woudl work and sound
better.  The other was soem the caps used to load/tune the fitler
were less than optimal in value.  In all grounding the cans helped
between 2-3 db in the overall shape and opposing sideband rejection.

My suggestion is unless you into building and tunign crystal fitlers
and have the gear leave it be.  You can break it faster than improve it.

Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO

Re: Opposite side band rejection ubitx V6

barry halterman

Allison, as always, appreciate your input. I have noticed that between my V4 and V6 there seems to be a noticable difference. The V4 tends to be better. I might try the grounding of the cases or change the termination caps to 100pf in my V6.
Thanks
Barry
K3bo

On Thu, Jun 18, 2020, 1:24 PM ajparent1/kb1gmx <kb1gmx@...> wrote:
I got to play with a bunch of them last year and the result...

The filters vary enough that a good one can easily exceed 40db and the
average was 35db.  One I hand optimized the filter did hit 45dB.

Overall of the filters seems rather narrow and those I measured were
under 2.1KHz wide A wider 2.4 to 2.7 KHz woudl work and sound
better.  The other was soem the caps used to load/tune the fitler
were less than optimal in value.  In all grounding the cans helped
between 2-3 db in the overall shape and opposing sideband rejection.

My suggestion is unless you into building and tunign crystal fitlers
and have the gear leave it be.  You can break it faster than improve it.

Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO