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On Fri, Aug 31, 2018 at 5:46 PM n5ib_2 < n5ib@...> wrote: The bias tee isn't used to power the T1, since it has internal battery power, and, with latching relays, only draws power when tuning.
The bias tee, using a lithium coin cell for DC power, fires an optical isolator at the antenna end that triggers the remote control line on the T1.
So the only connection between the Tx and the T1 is the coax.
N5IB
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Re: VK4PP uBitx LPF BANK add-on Board
The measurements that I made? for the daughterboard? bleed-through indicate that for the ENTIRE SYSTEM,? including the printed circuit board, connecting leads, relays, coils, coil wiring?and all the RF?wiring,? the bleed? through is almost NEGLIGIBLE. (lifted
the bottom green wire in the accompanying photo and measured bleed through that had to go through ALL SIX RELAYS).??? Far, far below the pass through the filter....? down to unmeasureable on the ICOM718..whereas properly filtered harmonics? were depressed
into the S5 or S6 range from 30dB overS9? fundamental (as predicted by others' measurements indicating the FILTERS had acceptable performance)??? ?Measurement performed?at 3.5? MHz.? Presumably capacitive coupling would increase related to frequency, perhaps
10 times the amount would be expected?at 30 MHz --- but that would only be 10dB more signal, perhaps reaching to S2? ?I don't want to risk my finals by doing? the experiment over and over.? ?The bleed through with a daughterboard --- even with unshielded
wires --- is far far far below? the requirements to meet FCC specs.? ? (-43 dB being? somewhere around S7.5 in my tests).? ? Get the relays separated, get the things apart physically that need to NOT bleed into each other....and it isn't that difficult
to fix the harmonics.? (The spurs are a different issue).? ?
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I interpret this measurement from Glenn:
? ? "-32dB from one set of contacts to the other. (common terminal)"
as being from KT1 pin 14 to pin 16 as seen in the uBitx schematic.
Also, interpret his -39 and -41 dB numbers to be from one relay section to the other,
which I averaged as -40dB.? ? For example, KT1 pin 12 to pin 5.
I now suspect those assumptions are incorrect, but the analysis could easily be adjusted to for any change to those two numbers.
Jerry
On Fri, Aug 31, 2018 at 03:40 AM, Glenn wrote:
All good points Warren.?? I did some checks of isolation using a typical DIP relay, type HK19F. DPDT
I made a small jig to hold the relays and measure isolation across contacts etc.
Typically it was -34dB across open contacts,
-32dB from one set of contacts to the other. (common terminal)
-41dB from open terminals on each side
-39dB from common of one pole to open on the other pole.
-48db from common to coil.
?At 30MHz.? Better as freq drops of course.
That's without effects of a PCB and various other traces.
glenn
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Re: VK4PP uBitx LPF BANK add-on Board
I interpret this measurement from Glenn:
? ? "-32dB from one set of contacts to the other. (common terminal)"
as being from KT1 pin 14 to pin 16 as seen in the uBitx schematic.
Also, interpret his -39 and -41 dB numbers to be from one relay section to the other,
which I averaged as -40dB.? ? For example, KT1 pin 12 to pin 5.
I now suspect those assumptions are incorrect, but the analysis could easily be adjusted to for any change to those two numbers.
Jerry
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On Fri, Aug 31, 2018 at 03:40 AM, Glenn wrote:
All good points Warren.?? I did some checks of isolation using a typical DIP relay, type HK19F. DPDT
I made a small jig to hold the relays and measure isolation across contacts etc.
Typically it was -34dB across open contacts,
-32dB from one set of contacts to the other. (common terminal)
-41dB from open terminals on each side
-39dB from common of one pole to open on the other pole.
-48db from common to coil.
?At 30MHz.? Better as freq drops of course.
That's without effects of a PCB and various other traces.
glenn
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Re: VK4PP uBitx LPF BANK add-on Board
In many places, I said "30m" when I should have said 10m (or 30mhz) in that previous post.
Here's an edited version:
The relays are not that bad, primary issue on the uBitx is how the board is routed.?
Look at the uBitx schematic, find KT1 near the 10m (10 meters, or 30mhz) LPF of L11,12,13.
Assume the relays are in the relaxed state as drawn, for operation at 10m.
The 32dB number is for isolation from KT1 pin 14 to 16.
So when operating at 10m, we have 32dB of loss going from pin 14 to pin 16,?
through the 20m filter at L14,15,16, and then another 32dB of loss
going from KT1 pin 1 to 3 at the other side of the filters.? A total of 64dB down
to sneak around the KT1 filter by that path.? The third filter is not a factor for this
since it is an additional 64dB down.??
The roughly 40dB loss in going around the 10m LPF from KT1 pin 12 to 5
is the primary factor that the relays themselves contribute to blow-by,
that's acceptable unless the PA is putting out harmonics that are as strong as the fundamental.
That 40dB path disappears if we use 3 additional relays at the far side of the LPF's.
?
Blow-by when operating on 10m is the primary consideration,
operating at lower frequencies will have proportionally less capacitive coupling through the relays.
Someone proposed the scheme below a few weeks ago using?a total of 4 DPDT relays?
which I have named RA, RB, RC, RD.
I forget exactly who brought this up, it came as a web pointer to schematics for a board in production.?
There's blow-by when operating on 10m of 32+32=64dB through RB, RD, and the 20m LPF.
There is also a path of path across RA, RC, and the 40m LPF of 32+32=64dB.
And a path across the RB and RD relay sections of 40+40=80dB through that same 40m LPF.
With all three blow-by paths of 64,64, and 80 dB in parallel, we have a net of about 57dB of blow-by.
Not bad for just 4 relays, and the board routes sort out nicely.
? ? ? ? ? ? ? ? ? ? o---------[10m]---------o
? ? ? ? ? ? ? ?+----o RB? ? ? ? ? ? ? ? ?RD o----+
? ? ? ? ? ? ? ?|? ? o---------[20m]---------o? ? |
? ? ? ? ? ? ? ?|? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?|
? ? ? ? ?o-----+? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?+--------o
---------o RA? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? RC o---------
? ? ? ? ?o-----+? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?+--------o
? ? ? ? ? ? ? ?|? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?|
? ? ? ? ? ? ? ?|? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?|
? ? ? ? ? ? ? ?|? ? o---------[40m]---------o? ? |
? ? ? ? ? ? ? ?+----o RB? ? ? ? ? ? ? ? ?RD o----+
? ? ? ? ? ? ? ? ? ? o---------[80m]---------o
Jerry, KE7ER
?
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I could probably help but I don't have any black pla to print with. Here in Tucson we have a maker space called xero craft. You may have one where you live. Xero for example has a couple of printers that can be used for a donation. Another option would be to use shapeway or some other site that will print and mail an object for a fee.
Feel free to contact me if you are willing to pay for a spool of filament and I will be happy to do it.
Chris
On Fri, Aug 31, 2018, 8:31 AM David Posthuma < davep@...> wrote: I am using the 4.2" Nextion?touch screen on my Ubitx. Does anyone know where I can get a small black bezel/frame for it? I only need about 1/4-inch on all sides. Unfortunately, I don't have access to a 3D printer. Thank you for any leads the group may provide.
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The bias tee isn't used to power the T1, since it has internal battery power, and, with latching relays, only draws power when tuning.
The bias tee, using a lithium coin cell for DC power, fires an optical isolator at the antenna end that triggers the remote control line on the T1.
So the only connection between the Tx and the T1 is the coax.
N5IB
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Re: VK4PP uBitx LPF BANK add-on Board
I decided to test the? little daughterboard system that I built to move the input filtering off theboard.
Everything connected:? 80 metersignal (has to go thru three relays on the board and 3 relays off the board):? S9+30 dB in my apprxoimately 70db attenuation system.
Remove the wire from the soldered-to-the-trace input to just the 80 meter LPF, lay it a couple centimeters to the side....
Signal? dropped to barely hearable and S0.
30 db for? the portion above S9? (verified with attentuators)
18 db more toget to S7.5? (verified? with attentuators)
Unknown from S7.5 to S0 but likely at? least 6db/Sunit (sincethose above7 were 12dB perS unit measured) --42 db
Total isolation at 80 meters roughly 90 dB
?at the very least (down to the verified? S7.5 point) 48 dB + whatever it takes to go from 7.5 to0??
Icom718.
So the isolation at 80 meters seems good....probably declines with frequency?
gordon
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All good points Warren.?? I did some checks of isolation using a typical DIP relay, type HK19F. DPDT
I made a small jig to hold the relays and measure isolation across contacts etc.
Typically it was -34dB across open contacts,
-32dB from one set of contacts to the other. (common terminal)
-41dB from open terminals on each side
-39dB from common of one pole to open on the other pole.
-48db from common to coil.
?At 30MHz.? Better as freq drops of course.
That's without effects of a PCB and various other traces.
glenn
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One other thing on the Elecraft T1 autotuner. ?I remember something that Wayne Burdick, N6KR (Elecraft founder and CEO) said about the T1. ?During initial testing of it, he messed up and accidentally hit it with 100 watts for a brief period (It's spec'd for 20W CW max) and it survived. ?Of course, this isn't recommended but it speaks well for Elecraft's product quality. ?
I have one I use regularly in portable ops with rigs other than my KX2 and I built 2 from the kits for others who didn't want to attempt the very close soldering necessary to install the relays in it. ?
I've had mine for over 5 years now and it runs just fine. ?I had forgotten about N5IB's "bias tee" but that's a really good way to power it remotely. ?You still have to use a separate remote cable and that must be well shielded, but you wouldn't have to be checking on the battery all the time. ?
The T1 should handle a stock 10-20 watt uBITX with no problem and will match some pretty wierd antenna configurations on many bands.
Jim, W0EB
------ Original Message ------
Sent: 8/31/2018 10:11:15 AM
Subject: Re: [BITX20] ATU for mBITX
I've built 3 of them and they remote very easily but you do have to use well shielded cables as any RF pickup tends to mess up the tuning.
Elecraft's software is NOT hackable and is proprietary, not open-source. ?
Jim
------ Original Message ------
Sent: 8/31/2018 10:04:33 AM
Subject: Re: [BITX20] ATU for mBITX
There is already a jack to remote control it.? See manual.
rOn
On August 31, 2018 at 8:50 AM "Tom, wb6b" <wb6b@...> wrote:
On Thu, Aug 30, 2018 at 09:36 AM, ajparent1/KB1GMX wrote:
T1 its the ideal pocket sized ATU That's a cool Auto Tuner. Did not realize Elecraft made a reasonable cost Auto ATU. Wonder how hard it would be to hack it, so I could put in in a weather proof box at my antenna and remotely control it?
Tom, wb6b
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Re: VK4PP uBitx LPF BANK add-on Board
Warren,
The relays are not that bad, primary issue on the uBitx is how the board is routed.?
Look at the uBitx schematic, find KT1 near the 30m LPF of L11,12,13.
Assume the relays are in the relaxed state as drawn, for operation at 30m.
The 32dB number is for isolation from KT1 pin 14 to 16.
So when operating at 30mhz, we have 32dB of loss going from pin 14 to pin 16,?
through the 20m filter at L14,15,16, and then another 32dB of loss
going from KT1 pin 1 to 3 at the other side of the filters.? A total of 64dB down
to sneak around the KT1 filter by that path.? The third filter is not a factor for this
since it is an additional 64dB down.??
The roughly 40dB loss in going around the 30m LPF from KT1 pin 12 to 5
is the primary factor that the relays themselves contribute to blow-by,
that's acceptable unless the PA is putting out harmonics that are as strong as the fundamental.
That 40dB path disappears if we use 3 additional relays at the far side of the LPF's.
?
Blow-by when operating on 30m is the primary consideration,
operating at lower frequencies will have proportionally less capacitive coupling through the relays.
Someone proposed the scheme below a few weeks ago using?a total of 4 DPDT relays
which I have named RA, RB, RC, RD.
I forget exactly who brought this up, it came as a web pointer to schematics for a board in production.?
There's blow-by when operating on 30m of 32+32=64dB through RB, RD, and the 20m LPF.
There is also a path of path across RA, RC, and the 40m LPF of 32+32=64dB.
And a path across the RB and RD relay sections of 40+40=80dB through that same 40m LPF.
With all three blow-by paths of 64,64, and 80 dB in parallel, we have a net of about 57dB of blow-by.
Not bad for just 4 relays, and the board routes sort out nicely.
? ? ? ? ? ? ? ? ? ? o---------[10m]---------o
? ? ? ? ? ? ? ?+----o RB? ? ? ? ? ? ? ? ?RD o----+
? ? ? ? ? ? ? ?|? ? o---------[20m]---------o? ? |
? ? ? ? ? ? ? ?|? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?|
? ? ? ? ?o-----+? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?+--------o
---------o RA? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? RC o---------
? ? ? ? ?o-----+? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?+--------o
? ? ? ? ? ? ? ?|? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?|
? ? ? ? ? ? ? ?|? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?|
? ? ? ? ? ? ? ?|? ? o---------[40m]---------o? ? |
? ? ? ? ? ? ? ?+----o RB? ? ? ? ? ? ? ? ?RD o----+
? ? ? ? ? ? ? ? ? ? o---------[80m]---------o
Jerry, KE7ER
?
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On Fri, Aug 31, 2018 at 06:01 AM, Warren Allgyer wrote:
That 32 dB number is the killer for the uBitx relay scheme. It gets at least 3 dB worse with each relay added to the chain and all four relays are in the chain.
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I am using the 4.2" Nextion?touch screen on my Ubitx. Does anyone know where I can get a small black bezel/frame for it? I only need about 1/4-inch on all sides. Unfortunately, I don't have access to a 3D printer. Thank you for any leads the group may provide.
|
look at the "Bias Tee" link at <>
for a way to remote the Elecraft T1 and run power on the coax.
Each of the two Bias Tee units will fit the traditional Altoids tin.
The T1 tuner and its Bias Tee can be fitted into a weatherproof box at the antenna
At the Tx end an SWR meter is needed to monitor/verify the match.
N5IB
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I've built 3 of them and they remote very easily but you do have to use well shielded cables as any RF pickup tends to mess up the tuning.
Elecraft's software is NOT hackable and is proprietary, not open-source. ?
Jim
------ Original Message ------
Sent: 8/31/2018 10:04:33 AM
Subject: Re: [BITX20] ATU for mBITX
There is already a jack to remote control it.? See manual.
rOn
On August 31, 2018 at 8:50 AM "Tom, wb6b" <wb6b@...> wrote:
On Thu, Aug 30, 2018 at 09:36 AM, ajparent1/KB1GMX wrote:
T1 its the ideal pocket sized ATU That's a cool Auto Tuner. Did not realize Elecraft made a reasonable cost Auto ATU. Wonder how hard it would be to hack it, so I could put in in a weather proof box at my antenna and remotely control it?
Tom, wb6b
|
There is already a jack to remote control it.? See manual.
rOn
On August 31, 2018 at 8:50 AM "Tom, wb6b" <wb6b@...> wrote:
On Thu, Aug 30, 2018 at 09:36 AM, ajparent1/KB1GMX wrote:
T1 its the ideal pocket sized ATU That's a cool Auto Tuner. Did not realize Elecraft made a reasonable cost Auto ATU. Wonder how hard it would be to hack it, so I could put in in a weather proof box at my antenna and remotely control it?
Tom, wb6b
|
Re: BITX40 Saving Settings Issue
Thanks Allard. I will check for ground loops.?
Also so I was not clear. When I do a reset to the default, it does sense the cw present and I have the cw configuration in settings. However when I turn off the rig and then back on, it does not sense the cw.?
73,
Gary K4 VI G
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You can't go wrong with it :) how much power can the polyvaricon handle?
Il 31/ago/2018 15:09, "Tom, wb6b" < wb6b@...> ha scritto: On Fri, Aug 31, 2018 at 04:44 AM, Peter Parker wrote:
I would go for a simple manual ATU.
Tom, wb6b
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please go thro the link ?It might help you.
Hi Ben,
Send me your RS274D files....? lynatmts@...
Lyn WA4GEH
--
"You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat."
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That's the display contrast setting?
Sent from my Samsung Galaxy smartphone.
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-------- Original message -------- From: SaMa photo SaMa photo <infosamaphoto@...> Date: 31/08/2018 14:15 (GMT+00:00) Subject: [BITX20] Raduino setting
Good evening
the trimmer mounted on raduino what is it for?
thank you
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Good evening
the trimmer mounted on raduino what is it for?
thank you
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On Fri, Aug 31, 2018 at 04:44 AM, Peter Parker wrote:
I would go for a simple manual ATU.
This may now be my favorite antenna tuner.  Tom, wb6b
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Re: VK4PP uBitx LPF BANK add-on Board
Glenn
That 32 dB number is the killer for the uBitx relay scheme. It gets at least 3 dB worse with each relay added to the chain and all four relays are in the chain.
WA8TOD
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Jim Sheldon
David Posthuma