A close up sharp photo will help to check.
V3 or V4 ?
Raj
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At 16/10/2018, you wrote: Hello All,
I just finished implementing the 45 Mhz crystal filter fix with the 7:2 impedance matching transformer on the output of the crystal. Now I am hearing myself in the speaker when I transmit and I am seeing the carrier wave on the SA when I push the PTT on the mic.
I not sure why the crystal filter mod would be related to these two issues. Anyone experience anything similar?
Ripley
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One of the first thing I tried was shielding. The PA, 30MHz LPF and 45MHz filter and even the
first BiDi amp. The whole effort made a little improvement but I was not satisfied.
I even tried soldering old IF transformer cans that I have a lot of...
Raj
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At 16/10/2018, you wrote: Maybe this is a stupid question but wouldn't it be possible to just shield the original toroids from electromagnetic influences?
I have a small copper cube made from plumbers Sheet copper in mind which could be connected to the ground on the underside.
Or is this just a little bit na?ve?
I would actually give it a try myself - but as I do not have a spectrum analyzer, I would not be able to find out if it did help or not.
Of course changing them to SMD inductors is easier - but this way the high Q toroids could be preserved.
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I have a factory stock Raduino for sale. It has the KD8CEC software now but came with the factory software installed. Only used a couple of hours until I got my original board fixed and calibrated. Excess to my needs at present.
$35 total shipped to Continental US and PayPal preferred.?
Other shipping, please ask..?
--
72 and God bless
KD4EPG
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Mad,
Going to Axicom relays looks like it pretty much cleans up our issues with harmonics.
But this thread is about spurs, not harmonics.
Raj has found that replacing the toroids at L5,L7 around Y1
and also L1,L2,L3,L4 on the 30mhz LPF with SMD inductors will clean up the spurs.
With both spurs and harmonics cleaned up, the rig can met regs.
Yes, the board layout is not ideal.
Board layout is why we have coupling from the power amp into Raj's L5 and L7.
But looks like replacing some relays and inductors is all we need do
to clean up the spurs and harmonics well enough to meet regs.
(We might need to clean up a trace around the 40mhz transmit LPF, I'm not sure.)
Regarding Sascha's question:?
? ?"wouldn't it be possible to just shield the original toroids from electromagnetic influences?"
I think it very well could work, worth trying if you have shielding on hand but not the SMD inductors.
Copper blocks electric fields (and electromagnetic waves) quite well.
Though if it's stray magnetic fields that's causing trouble, maybe not.
Replacing the toroids with surface mount inductors seems easier to me
than adding well grounded copper cages around the toroids.
Jerry, KE7ER
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On Mon, Oct 15, 2018 at 05:52 PM, MadRadioModder wrote:
It¡¯s the PCB tracks/ /layout and relays that are the problem¡ not the toroids/ toroid layout.
?
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Maybe a shield between the PA / LPF section and Mixer sections. Aand changing the relays. and maybe a few SMD inductors in the power feed to the RX section....
73 Nick VK4PP
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It¡¯s the PCB tracks/ /layout and relays that are the problem¡ not the toroids/ toroid layout. ? ? MRM ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Sascha Bohnet | DL5SMB via Groups.Io
Sent: Monday, October 15, 2018 5:45 PM
To: [email protected]
Subject: Re: [BITX20] Simpler spur fix ? Maybe this is a stupid question but wouldn't it be possible to just shield the original toroids from electromagnetic influences?
I have a small copper cube made from plumbers Sheet copper in mind which could be connected to the ground on the underside.
Or is this just a little bit na?ve?
I would actually give it a try myself - but as I do not have a spectrum analyzer, I would not be able to find out if it did help or not.
Of course changing them to SMD inductors is easier - but this way the high Q toroids could be preserved. -- ¡_. _._
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Re: Harmonics and Relay Replacement
I plan on doing the same. I already safely removed the 8 pin Op amp very clean too. So I shouldn¡¯t have any issue with the relays, hopefully. Waiting to order mine.
Joe
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On Oct 15, 2018, at 4:24 AM, Matthias Zwoch <zwoch@...> wrote:
Am 14.10.2018 um 23:57 schrieb Joe Puma:
Yea but changing the relays looks like the real winner here. Hello Joe,
It is not a big problem to get the HFD27 desoldered. A good desolder litz (I used 2,5mm from Felder) and a bit judding and pulling an they will come out without any damages at the PCB and the relais. Desoldered all 5. They will go in the scrapbox and this evenig the AXICOMs will take their places.
73, Matthias DD7NT
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Maybe this is a stupid question but wouldn't it be possible to just shield the original toroids from electromagnetic influences?
I have a small copper cube made from plumbers Sheet copper in mind which could be connected to the ground on the underside.
Or is this just a little bit na?ve?
I would actually give it a try myself - but as I do not have a spectrum analyzer, I would not be able to find out if it did help or not.
Of course changing them to SMD inductors is easier - but this way the high Q toroids could be preserved.
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Just assembled mine, had a faulty joint on encoder. Check it as I suspect it is associated with no tuning. Display is sign much is working. Once tuning is working, the work the audio. Rig does not have lots of excessive gain, so do advance the volume control. On my board the bfo was way off, so search for tune up instructions.
Curt
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Re: I HAVE 2 AGC AND POP FIX BOARDS COMPLETE WITH DIAGRAMS FOR SALE.MAKE ME AN OFFER DAVE G0AYD
I will buy the AGC board with components.? $15.00 ?
On Mon, Oct 15, 2018 at 2:30 PM Dave Dixon < wylyeguy2@...> wrote: the AGC & POP fix boards are by N6 DT..
On Mon, 15 Oct 2018 at 16:58, John Lauber < jlauber@...> wrote: Will you take $10?? I¡¯ll pay with PayPal. John WI6P ? From: [email protected] <[email protected]> On Behalf Of Dave Dixon
Sent: Monday, October 15, 2018 08:03
To: [email protected]
Subject: [BITX20] I HAVE 2 AGC AND POP FIX BOARDS COMPLETE WITH DIAGRAMS FOR SALE.MAKE ME AN OFFER DAVE G0AYD ?
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Looking for some insight from the group as where to look.
I assembled my unit, checked all connections, and turned it on. All I am getting on the display is "CW 7.150", no audio and no action with the encoder. The mic and speaker are attached and even attached a Bencher. The software is original from uBitx.
Thanks for any help.
John
K1VOI
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Hello All, ? I just finished implementing the 45 Mhz crystal filter fix with the 7:2 impedance matching transformer on the output of the crystal. Now I am hearing myself in the speaker when I transmit and I am seeing the carrier wave on the SA when I push the PTT on the mic. ? I not sure why the crystal filter mod would be related to these two issues. Anyone experience anything similar? ? Ripley ? ? Sent from for Windows 10 ?
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From: Raj vu2zapSent: Sunday, October 14, 2018 2:52 AM To: [email protected]Subject: Re: [BITX20] Simple spur fix ? Lev, Any experiments on this ?
At 05/09/2018, you wrote:
Would that be a good solution to make the IF amplifier tuned? Like this? Also, change the transistors to BFS17P, this is more suited to RF.
73s de HA5OGL
On Wed, Sep 5, 2018 at 10:46 AM Raj vu2zap < rajendrakumargg@...> wrote: This fix reduced the spurs by up to 10 db?? and requires ONLY ONE part to be added. There is big change above 10MHz in the board. There is some improvement below also.
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Re: I HAVE 2 AGC AND POP FIX BOARDS COMPLETE WITH DIAGRAMS FOR SALE.MAKE ME AN OFFER DAVE G0AYD
Hi Dave,
I'll take one, let me know how to contact/pay you.
Nigel.
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Re: Harmonics and Relay Replacement
Mounted the AXICOM V23105-A5303-A201 this evening. Replaced all HFD27. And bingo - the harmonics on 3,5 / 7 /10.5 meet the german RegTP requirements (-40 dB). Would also meet the -43 FCC limit. For the higher bands I will test later. Need the HP boatanchors at our local club for that. Bought the relais from the ebay seller "breconjess" UK.
So the first problem is solved. Next are the spur fixes, then AGC...
73 Matthias, DD7NT
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Re: I HAVE 2 AGC AND POP FIX BOARDS COMPLETE WITH DIAGRAMS FOR SALE.MAKE ME AN OFFER DAVE G0AYD
Hello John ??????????????? the boards are by N6 DT and come with all componants plus circuit diagram, $10 is fine for one full set of agc...pop fix boards, plus post to your country ill ifnd out what that is.regards Dave.
On Mon, 15 Oct 2018 at 16:58, John Lauber < jlauber@...> wrote: Will you take $10?? I¡¯ll pay with PayPal. John WI6P ? From: [email protected] <[email protected]> On Behalf Of Dave Dixon
Sent: Monday, October 15, 2018 08:03
To: [email protected]
Subject: [BITX20] I HAVE 2 AGC AND POP FIX BOARDS COMPLETE WITH DIAGRAMS FOR SALE.MAKE ME AN OFFER DAVE G0AYD ?
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Re: I HAVE 2 AGC AND POP FIX BOARDS COMPLETE WITH DIAGRAMS FOR SALE.MAKE ME AN OFFER DAVE G0AYD
the AGC & POP fix boards are by N6 DT..
On Mon, 15 Oct 2018 at 16:58, John Lauber < jlauber@...> wrote: Will you take $10?? I¡¯ll pay with PayPal. John WI6P ? From: [email protected] <[email protected]> On Behalf Of Dave Dixon
Sent: Monday, October 15, 2018 08:03
To: [email protected]
Subject: [BITX20] I HAVE 2 AGC AND POP FIX BOARDS COMPLETE WITH DIAGRAMS FOR SALE.MAKE ME AN OFFER DAVE G0AYD ?
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Re: Recommended fixes on ubitx.net
Jerry - thank you so much for the positive words. The encouragement is much appreciated. I may have contributed to my own problems by overdriving the audio via my sound card or ground loops, etc.? So I'm building an easy Digi board and I'll figure out the appropriate drive levels.?
And go from there!
Thanks again.
Don
Km4udx?
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Re: Harmonics and Relay Replacement
Thanks Nigel appreciated
Sent from my Samsung Galaxy smartphone.
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-------- Original message -------- From: Nigel G4ZAL <nigel@...> Date: 15/10/2018 17:03 (GMT+00:00) Subject: Re: [BITX20] Harmonics and Relay Replacement
This seller on ebay UK is selling packs of 2 or 4 - I grabbed some 4's ;-) Nigel
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Re: Harmonics and Relay Replacement
Even RS componenets have them ?I had ordered on
On Mon, Oct 15, 2018 at 9:33 PM Nigel G4ZAL < nigel@...> wrote: This seller on ebay UK is selling packs of 2 or 4 - I grabbed some 4's ;-)
Nigel
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Raj vu2zap
Nick VK4PP
MadRadioModder
Ripley
