Re: Harmonics and Relay Replacement
Great find, Sarma, as the world continues to look into this problem.
I'll run a test later today with the 1mH inductor isolation of the relay coils and then see the effect of adding a 10nF capacitor across the coil. May be dependent on how the relay contact wiring is configured and what is on each armature. I wouldn't think there is a radiated problem between relays as he implies .....conducted, yes.
73 Kees K5BCQ?
|
Re: Harmonics and Relay Replacement
Good Morning Jim, Thanks for entertaining the idea.? Your shared data maybe useful as you have shown same board and relay with different measured results. For that particular board and the measurement data you gathered, I would say the results ARE encouraging from this viewpoint: You have 4.5 dBc more margin to FCC spec on your worst case data point (40m 3rd harmonic) with the supplied data set.  Comments: I have no measurement error / uncertainty reference or relevant personal judgement / experience to truly offer. But, I would think it more difficult to accurately measure the case of more suppression, and so the uncertainty here would be higher. Note that the 2nd and 3rd harmonics are swapping (80m Top and 17m Bot) Regards, Gary AG5TX
|
Re: Harmonics and Relay Replacement
Thanks for those pictures, Sarma. To me, that seems to indicate even closer coupling from the relay armature to the coil. Bad for RF.
73 Kees K5BCQ
|
Re: Harmonics and Relay Replacement
This is a cool find. Nice read.?
toggle quoted message
Show quoted text
On Oct 12, 2018, at 6:49 AM, Mvs Sarma < mvssarma@...> wrote: Regarding Filters and axicom realy towards band switching? , i saw an useful link.
?
Perhaps it helps.
regards
sarma
?vu3zmv
|
Sorry Owen,
Missed your reply.
I put the inductors in a convenient place without obliterating the
component legends.
The seller on eBay had mentioned that they were Murata, the size may be
1210, slightly fatter than 1206.
Shielding the toroid made a slight change but this issue may be because
of hi Q ringing. I just soldered them
as I saw fit and placed them at right angles to the toroid. That worked..
it also works in the exact place or
the old toroids.
Mike:
I think a combination of Q and small size and probably they are
internally shielded I don't know.
I also replaced L1-4 with 330nH SMD and that helps a little on one test
board.
My interest was to fix these problem with the simplest solution without
major surgery. The next gen
board will probably be bigger with more inexpensive relays like two
relays per filter.
The Axicom relays cost me about 5$ landed and taxed.. I am only going to
change KT1,2,3 but in
production the cost has to be kept down in true BITX spirit.
Raj
At 12/10/2018, you wrote:
toggle quoted message
Show quoted text
I'd like to second this question
about the required inductors. Is it that the SMD inductors have a lower
Q, or is it the smaller physical size, or the change in position, or a
combination of all these changes?
Thanks
Mike M.
KU4QO?
On Wed, Oct 10, 2018 at 12:01 PM ohwenzelph via Groups.Io
<Ohwenzelph=
[email protected]> wrote:
- I like this, but...
- looks like you left C215 in but took C211 out of the circuit, does it
matter? Maybe not..
- are you sure they are Murata? Are they shielded? Probably not exactly
1206, maybe 1210.
- does shielding matter, does the self resonant frequency matter? If it
works, I just want to be able to duplicate it!
- thanks so much
|
I'd like to second this question about the required inductors. Is it that the SMD inductors have a lower Q, or is it the smaller physical size, or the change in position, or a combination of all these changes?
Thanks Mike M. KU4QO?
On Wed, Oct 10, 2018 at 12:01 PM ohwenzelph via Groups.Io <Ohwenzelph= [email protected]> wrote: I like this, but...
looks like you left C215 in but took C211 out of the circuit, does it matter? Maybe not..
are you sure they are Murata? Are they shielded? Probably not exactly 1206, maybe 1210.
does shielding matter, does the self resonant frequency matter? If it works, I just want to be able to duplicate it!
thanks so much
_._,_._,_
|
Re: Harmonics and Relay Replacement
Interesting link by this Italian guy, surely not a macaroni one hihi, he also says to add a capacitor across (?) the coil.
Il 12/ott/2018 12:49, "Mvs Sarma" < mvssarma@...> ha scritto: Regarding Filters and axicom realy towards band switching? , i saw an useful link.
?
Perhaps it helps.
regards
sarma
?vu3zmv
|
Re: Harmonics and Relay Replacement
Regarding Filters and axicom realy towards band switching? , i saw an useful link.
?
Perhaps it helps.
regards
sarma
?vu3zmv
|
Re: Harmonics and Relay Replacement
I had an old Panasonic DS2E relay. Here are top and side exploded photos. Sorry for lack of clarity
The contacts can be seen mounted on either side of the relay. The armature moves sideways pulling one and pushing another contact.
regards
sarma
?vu3zmv
|
Turn off 2- Step Verification
- Open your Google Account.
- In the "Sign in & security" section, select
2-Step Verification. You might need to sign in.
- Select Turn off.
- A pop-up window will appear to confirm that you want to turn off
2-Step Verification. Select Turn off.
From the net!
Raj
At 12/10/2018, you wrote:
toggle quoted message
Show quoted text
I was using 2 factor
authentication with Google. It is still set for my
account, and I need to get it
turned off. How do I contact a group admin or someone that can help fix
my account?
Mike
AI4NS
--
Mike
AI4NS
|
Re: Recommended mods for spurs and harmonics
On Fri, Oct 12, 2018 at 09:06 AM, Jerry Gaffke wrote:
We do have insufficient local oscillator drive from CLK1 into the mixer,
Has anyone tried changing the attenuator from 6db to a 3db one? 73 NIck VK4PP
|
Mike? AI4NS
What is this "2-factor authentication with Google" that you mentioned?? I just looked at your
member profile on the BITX20 site and see nothing like that on Groups.io.? You are set for
All Messages, and Full Featured Digest.?
Arv? K7HKL _._
I was using 2 factor authentication with Google. It is still set for my account, and I need to get it turned off. How do I contact a group admin or someone that can help fix my account?
Mike AI4NS
--
Mike
AI4NS
|
I was using 2 factor authentication with Google. It is still set for my account, and I need to get it turned off. How do I contact a group admin or someone that can help fix my account?
Mike AI4NS -- Mike AI4NS
|
Recommended mods for spurs and harmonics
There were a bunch of spurs coming out of that first mixer into the 30mhz LPF on transmit that were below 30mhz. One in particular (first flagged by Allison) was at? (45mhz - Carrier), so transmitting at 21mhz we got a spur at 45-21=24mhz. Some of the spurs were be due to unwanted coupling from the power amp back into that 45mhz IF. This issue is possibly addressed by Raj's hack at L5 and L7:?? ? ?? /g/BITX20/message/60453Raj previously had some success with adding a second 45mhz crystal filter, but it's looking like the L5,L7 hack may be a better solution. ? ?? /g/BITX20/topic/25208658The four relay switched transmit LPF's do not attenuate harmonics as well as they should, as first pointed out by Warren. Many have addressed this with major hacks to the uBitx board, or by adding external filters in line with the antenna.? But it is now looking like this can be adequately addressed (except 40m) by simply replacing the relays with the Axicom, which is more suitable for switching RF: ? ?? /g/BITX20/message/60368With luck, 40 meters can also be cleaned up with a minor mod to the board traces while swapping out the relays. Kees is looking at various ways of improving the performance of the existing relays, if it works this may be easier and cheaper than replacing the relays: ? ?? /g/BITX20/topic/27240335We do have insufficient local oscillator drive from CLK1 into the mixer, and the related issue of too much signal coming in from the 45mhz IF. That will contribute intermodulation distortion. Also more carrier leakage than we should have. However these issues are close in to the transmitted signal, within the bandwidth used by a typical AM signal, and generally not a problem with regard to regulations. Yet another issue is inadequate power out on the high bands, such as 10 meters. Addressing this is perhaps best left for v5 of the uBitx, or perhaps grafting G0UPL's new QSX power amp to the uBitx:?? /g/BITX20/topic/27121196We need to have a clean signal before we worry about making it stronger. Some are using high power external linear amps with the uBitx. Not a good idea unless you first clean up the spurs, harmonics, IMD, and carrier leakage described here.? Between Raj's L5,L7 fix and cleaning up the relays around the transmit LPF's, the uBitx may be good enough to meet regs across all bands and all modes. Both of these fixes are starting to look cheap and easy enough to do. But unless you are the adventurous sort, I suggest holding back a few weeks till further reports are in. Jerry, KE7ER
On Thu, Oct 11, 2018 at 02:11 PM, ajparent1/KB1GMX wrote:
Did You make a measurement on the mirror reception which should be attenuated by the input lpf? Or is it another stone to be lifted?
A low pass filter at the input of Q90 is insufficient to remove anything below its cut of of about 33.5mhz.
This is not new new here, I just haven't mentioned it in the last 4 weeks, prior to that it was a near daily topic
so its gone to the collective forgetfulness.
Problem 11.996(approx) carrier osc leakage.? Board level issue with OSC0 propagation to other parts of the board.
Problem? mirror image of output and IF, spectral folding from mixing products and sampling theory.? Side effect of?
insufficient filtering results in spurs in the 16-17mhz range when tuned to 10M SSB.? The only way to filter that is
bandpass at the output of the mixer.
>>>>in the QRP-labs PA : the output stage fo the driver is using a center tapped transformer. Why not choose an extra bifilar wound choke as correctly done int the PA stage?? Did You try this configuration? <<<
Ask Hans but the design for that stage is low power so current effects in the transformer are minimal at that
power level.? ? In my work I'e done both and for that stage and power level its overkill.
?
Allison
|
OK, 3 more plots.? Mouser just delivered. The first one is with 680uH and the second is with 1mH. That's about 8dB better at 25MHz and below when compared to a plain uBITX "16 pin" relay. The third plot shows a plain "16 pin" HFD-27 relay for comparison with no inductance added to the coil leads. 73 Kees K5BCQ   
|
Re: QSX 10W HF Linear PA kit
On Thu, Oct 11, 2018 at 01:05 PM, Henning Weddig wrote:
Did You make a measurement on the mirror reception which should be attenuated by the input lpf? Or is it another stone to be lifted?
A low pass filter at the input of Q90 is insufficient to remove anything below its cut of of about 33.5mhz.
This is not new new here, I just haven't mentioned it in the last 4 weeks, prior to that it was a near daily topic
so its gone to the collective forgetfulness.
Problem 11.996(approx) carrier osc leakage.? Board level issue with OSC0 propagation to other parts of the board.
Problem? mirror image of output and IF, spectral folding from mixing products and sampling theory.? Side effect of?
insufficient filtering results in spurs in the 16-17mhz range when tuned to 10M SSB.? The only way to filter that is
bandpass at the output of the mixer.
>>>>in the QRP-labs PA : the output stage fo the driver is using a center tapped transformer. Why not choose an extra bifilar wound choke as correctly done int the PA stage?? Did You try this configuration? <<<
Ask Hans but the design for that stage is low power so current effects in the transformer are minimal at that
power level.? ? In my work I'e done both and for that stage and power level its overkill.
?
Allison
|
Re: Harmonics and Relay Replacement
Thanks Jim that helps. ?I may have been a bit optimistic about the test lead situation here.73 Scott
toggle quoted message
Show quoted text
On Oct 11, 2018, at 12:02 PM, Jim Sheldon < w0eb@...> wrote: Scott, Use the shortest leads possible, measure the inductance as quickly as you can after "Zeroing" your meter with the leads shorted. ?That's the way I do it. ?The inductance of the leads is a factor as well as the capacitance of your hand & fingers. ?Zero it, connect the inductor and get your hands back. ?Write down the reading as quick as you can. ?I also turn the unit on and leave it on for at least 10-15 minutes before doing any measurements with it. ?This applies to any LC meter, no matter the brand or the circuit it uses.
About the best advice I can give, ?maybe Raj does it differently and he will chime in also.
Jim - W0EB
------ Original Message ------
From: "Scott McDonald via Groups.Io" < ka9p@...> Sent: 10/11/2018 10:46:44 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
Hi Jim, or Raj, or ¡.
?
I have trouble with reproducibility on lower numbers with my recently purchased LC200.
?
Butt when I see people that know what they are doing having good results, I'm inclined to ask whether there is anything special, or for that matter, just how are you measuring the lower value inductances, figuring based on past experience that I may not have yet acquired the "knack."
?
Thanks, Scott ka9p
?
?
-----Original Message-----
From: Jim Sheldon < w0eb@...>
To: BITX20 < [email protected]>
Sent: Thu, Oct 11, 2018 9:37 am
Subject: Re: [BITX20] Harmonics and Relay Replacement
Hi Raj,
Funny, I have a DE-5000, LC-100A (real cheap one from eBay) and the AADE
and they all agree within less than 1 percent. You might have a bad
crystal oscillator on the uP in your AADE? Or maybe I just got lucky as
I was given my AADE by a friend, several years ago. Not sure where he
got it.
The biggest surprise is how accurate the very inexpensive LC-100A has
been. I think I paid $9.95 USD with free shipping for it.
Jim, W0EB
------ Original Message ------
From: "Raj vu2zap" < rajendrakumargg@...>
To: [email protected]
Sent: 10/11/2018 3:45:22 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
>I don't trust my AADE meter below 1uH. I use a meter called DE 5000, it
>read commercial
>sub uH inductors very accurately. The AADE meter was way off.
>
>The DE meter can be set for 1,10,100 KHz measurement frequency. At 100K
>the meter
>reads 1nH
>
>Raj
>
>
>You will need the accesories TL-21 and 22 ..
>
>At 11/10/2018, you wrote:
>>Kees,
>>In measuring a Virtual relay and an Axicom relay that I have here,
>>both show approximately 20nH.
>
>
>
>
|
Emissions allowed In Band Segments
Wavelength band | Frequencies | Emission types authorized | Standards see ¡ì 97.307(f) , paragraph: | LF: | | | | 2200 m | Entire band | RTTY, data | (3). | 2200 m | Entire band | Phone, image | (1), (2). | MF: | | | | 160 m | Entire band | RTTY, data | (3). | 160 m | Entire band | Phone, image | (1), (2). | 630 m | Entire band | RTTY, data | (3). | 630 m | Entire band | Phone, image | (1), (2). | HF: | | | | 80 m | Entire band | RTTY, data | (3), (9). | 75 m | Entire band | Phone, image | (1), (2). | 60 m | 5.332, 5.348, 5.3585, 5.373 and 5.405 MHz | Phone, RTTY, data | (14). | 40 m | 7.000-7.100 MHz | RTTY, data | (3), (9) | 40 m | 7.075-7.100 MHz | Phone, image | (1), (2), (9), (11) | 40 m | 7.100-7.125 MHz | RTTY, data | (3), (9) | 40 m | 7.125-7.300 MHz | Phone, image | (1), (2) | 30 m | Entire band | RTTY, data | (3). | 20 m | 14.00-14.15 MHz | RTTY, data | (3). | 20 m | 14.15-14.35 MHz | Phone, image | (1), (2). | 17 m | 18.068-18.110 MHz | RTTY, data | (3). | 17 m | 18.110-18.168 MHz | Phone, image | (1), (2). | 15 m | 21.0-21.2 MHz | RTTY, data | (3), (9). | 15 m | 21.20-21.45 MHz | Phone, image | (1), (2). | 12 m | 24.89-24.93 MHz | RTTY, data | (3). | 12 m | 24.93-24.99 MHz | Phone, image | (1), (2). | 10 m | 28.0-28.3 MHz | RTTY, data | (4). | 10 m | 28.3-28.5 MHz | Phone, image | (1), (2), (10). | 10 m | 28.5-29.0 MHz | Phone, image | (1), (2). | 10 m | 29.0-29.7 MHz | Phone, image | (2). | VHF: | | | | 6 m | 50.1-51.0 MHz | MCW, phone, image, RTTY, data | (2), (5). | Do | 51.0-54.0 MHz | MCW, phone, image, RTTY, data, test | (2), (5), (8). | 2 m | 144.1-148.0 MHz | MCW, phone, image, RTTY, data, test | (2), (5), (8). | 1.25 m | 219-220 MHz | Data | (13) | Do | 222-225 MHz | RTTY, data, test MCW, phone, SS, image | (2), (6), (8) | UHF: | | | | 70 cm | Entire band | MCW, phone, image, RTTY, data, SS, test | (6), (8). | 33 cm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | 23 cm | Entire band | MCW, phone, image, RTTY, data, SS, test | (7), (8), and (12). | 13 cm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | SHF: | | | | 9 cm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | 5 cm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | 3 cm | Entire band | MCW, phone, image, RTTY, data, SS, test | (7), (8), and (12). | 1.2 cm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | EHF: | | | | 6 mm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | 4 mm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | 2.5 mm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | 2 mm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | 1mm | Entire band | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). | | Above 275 GHz | MCW, phone, image, RTTY, data, SS, test, pulse | (7), (8), and (12). |
? ? MRM
|
|
This email has been checked for viruses by AVG antivirus software.
|
-- ¡_. _._
|
Re: digital mode BITX QSO Afternoon/Evening, Sunday, October, 14 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.
?[grin]? ?except the ORIGINAL digital mode:? CW
cheers
gordon
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> on behalf of K5ESS <k5ess.nothdurft@...>
Sent: Thursday, October 11, 2018 4:34 PM
To: [email protected]
Subject: Re: [BITX20] digital mode BITX QSO Afternoon/Evening, Sunday, October, 14 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.
?
Digital modes not allowed on 7277. ?FCC 97.305
Mike
K5ESS
?
From: [email protected] [mailto:[email protected]]
On Behalf Of Don - KM4UDX
Sent: Thursday, October 11, 2018 1:22 PM
To: [email protected]
Subject: [BITX20] digital mode BITX QSO Afternoon/Evening, Sunday, October, 14 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.
?
I gave phone/SSB a go last sunday from Northern Virginia, no luck.
I have much better luck with PSK31 or JT8.?
Does any uBITXer want to try digital modes on 10/15??
If so, I'd vote for staying on the same 7277 but use psk31 just for fun?
Don
km4udx
|
Re: digital mode BITX QSO Afternoon/Evening, Sunday, October, 14 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.
Digital modes not allowed on 7277. ?FCC 97.305 Mike K5ESS ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Don - KM4UDX
Sent: Thursday, October 11, 2018 1:22 PM
To: [email protected]
Subject: [BITX20] digital mode BITX QSO Afternoon/Evening, Sunday, October, 14 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere. ? I gave phone/SSB a go last sunday from Northern Virginia, no luck.
I have much better luck with PSK31 or JT8.?
Does any uBITXer want to try digital modes on 10/15??
If so, I'd vote for staying on the same 7277 but use psk31 just for fun?
Don
km4udx
|
Raj vu2zap
Nick VK4PP
MadRadioModder