Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
Dremel? Butchery! Scalpel / craft knife (even box-cutter!) can do a neater safer job. Slice across both ends of the gap you want to create, use your soldering iron/station to overheat the section of track and swipe it sideways. Then use the blade to? scrape bare the track ends? for solder points.
73 de ZL2DEX
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While it sounds like the diodes are lower voltages, should this protect the relays from a near by xmitter??
This is the mod thats mentioned to protect Q13, wondering if the diodes I have will be good enough to protect it:
"At pin 12 of K1 relay solder 2 4148 diodes in parallel but in opposite polarity. This will limit the receiver from getting high RF voltage."
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The NTE109 is a Germanium diode, equivalent to a 1N270.? It turns on
at a lower voltage, about .3V, than a 1N4148 Silicon diode, which
turns on at about .6V.
David N1HAC
On 8/28/18 6:21 PM, Chris [N7CCX]
wrote:
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I am going through my stash of diodes and found I had a couple of
NTE 109 diodes..?
The diode is
60 mA Continuous Average Forward Current, 100V Peak Reverse
Voltage..
The 1n4148 is 10ma 20v reverse; significantly different
values.
Is the NTE still enough of a limit that the bitx40 would be
safe from a nearby xmitter???
Thanks!
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I am going through my stash of diodes and found I had a couple of NTE 109 diodes..?
The diode is 60 mA Continuous Average Forward Current, 100V Peak Reverse Voltage..
The 1n4148 is 10ma 20v reverse; significantly different values.
Is the NTE still enough of a limit that the bitx40 would be safe from a nearby xmitter???
Thanks!
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
Hope you find it. Better the one that is gone, than if one in the two filters for lower bands was lost.
Tom, wb6b
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
Well, here is the photo of my attempt at cutting traces with a Dremel 200 tool and a tiny little bit that looks like an end mill !! ?
I learned the hard way that you have to hold this thing with two hands, ?come straight vertical, and don¡¯t come anywhere close to the inductors.?
I managed to touch L 14 twice, first time knocked off one of its ?wires, another time and it went ZING! ?somewhere in my room and I haven¡¯t found it yet. ? ?So until I find it, that filter is only going to have two sections!
Once I learn to be that careful, it wasn¡¯t very difficult. ? I ?used low speed on the Dremel tool. ?If you work really slow or you can create a denuded solder point for a trace that you needed to cut, And then solder ?to.?
Because I hadn¡¯t planned this in advance, I don¡¯t have great options for mounting the board but I¡¯ll figure it out. ?
On Aug 28, 2018, at 17:09, Gibby,Gordon L < ggibby@...> wrote:
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Here are photos of the assembled board. ? I did break down and use shielded microphone cable for the relay control wires. ? Soldering those SMT inductors was a bit of a thrill with a Walmart soldering iron. ? As some of you suggested, I put the relays
on the ground plane side. ? The extra circuitry unused is for a regulated voltage.
<image1.jpeg>
On Tue, Aug 28, 2018 at 3:51 AM Tom, wb6b < wb6b@...> wrote:
Warren thanks,
I googled around and discovered I'm not the only one trying to prototype things with tiny chips. So, thanks for pointing the Adafruit one out. I'll order the Adafruit one or see what Digi-Key has.
Tom, wb6b
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UBITX V3 TX GAIN VARIATIONS
Investigating transmit gain in UBITX V3 using LTSPICE, Aug 28, 2018
Caveats:
all modeling done at 13.8vdc
For simplification:
q90 collector circuit modeled as parallel feed with 400 ohm load
q911-q912 collector circuit modeled as parallel feed with 200 ohm load
q92,q93 and q96,q97 collector circuit modeled as parallel feed
??????????????????? with 50 ohm load,each side
observations:
in the bidir amps the 2n3904 gain rolls off 1.2 db from 5MHz
to 45 MHz...not real bad; I believe 2n3904s are quite usable
in the bidir amps at 45 MHz.
In the TX:
q90 rolls off less than .5 db from 5 to 30 MHz
same for Q911-Q912
same for Q92,Q93,Q96,q97
so, adding q90 rolloff, and q911-912 rolloff, and q92,q93,q96,q97
rolloff I get (.5+.5+.5)= 1.5 db rolloff from 5 to 30 MHz.
My most recent ubitx v3 has 10W out on 40M, but less than 2W out on 15M.
That is more than 7dB drop.
I take it from the above that replacing the TX driver transistors with
higher Ft devices may not substantially improve the 15M performance.
WARNING: q911,q912,q92,q93,q96,q97 all dissipate at least 296 mW. That
means 250 mW transistors are not acceptable.
So, in searching for a better Ft device for the TX chain:
the BFR106 has the dissipation, but the 3.5 to 5GHz Ft invites instability
the MMBT10? ?? lists dissipation at 225 mW, so it may not be a good candidate
the MMBT2369 lists dissipation at 225 mW, so it may not be a good candidate
the DTX2222A has the dissipation, but the Ft is not better than 2n3904, and
the footprint is not compatible with the board.
So at this point, I do not see a real winner for 2n3904 replacement.
I am sure open to suggestions on this front.
All of the above really leads me to question the power amp circuit..
and I do not have the wherewithall to model that successfully.
Any ideas there?
Rod KM6SN
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Yes, but we know this is not perfect.? Wrong word should been reasonable.
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Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
Yes but you have no idea how many never found it.
rOn
On August 28, 2018 at 5:01 PM Christopher Miller <djmalak2k6@...> wrote:
The question would be then can it be changed, and did the ubitx exist when the group moved from yahoo?
I'm guessing no and no. So then you would have to create a new group and move thousands of members over a trivial thing like removing 20 from the group name. Clearly the problem isn't people finding or using the group.
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
Here are photos of the assembled board. ? I did break down and use shielded microphone cable for the relay control wires. ? Soldering those SMT inductors was a bit of a thrill with a Walmart soldering iron. ? As some of you suggested, I put the relays on the
ground plane side. ? The extra circuitry unused is for a regulated voltage.
toggle quoted message
Show quoted text
On Tue, Aug 28, 2018 at 3:51 AM Tom, wb6b < wb6b@...> wrote:
Warren thanks,
I googled around and discovered I'm not the only one trying to prototype things with tiny chips. So, thanks for pointing the Adafruit one out. I'll order the Adafruit one or see what Digi-Key has.
Tom, wb6b
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Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
The question would be then can it be changed, and did the ubitx exist when the group moved from yahoo?
I'm guessing no and no. So then you would have to create a new group and move thousands of members over a trivial thing like removing 20 from the group name. Clearly the problem isn't people finding or using the group.
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Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
Problem is the group name should be descriptive. Can't help what's in a description it is not in the name.
rOn
On August 28, 2018 at 4:06 PM Christopher Miller <djmalak2k6@...> wrote:
Considering the mods can't get people to stay on topic in a thread, why should it be assumed the same won't happen with subgroups? Who is going to spend the time moving topics around? Like Arv pointed out, you can mute threads.
To the guy pointing out the name of the group is bitx20, Read the group description.?
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Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
For several hours now I have composed and edited this message, now
before anybody adds any other comments to this thread I should probably
send this and piss everybody off.
It sounds to me that some people think the group is too big and needs to
be broken up. Now the one thing that attracted me to this group was the
community, people helping other people with various radio problems.
Personal opinion here, break up the group you may kill the community.
How to handle the flow.
Digests have been mentioned. My personal experience with digests in
another group in the past was that the digest pretty much trashed all
threading and made everything hard to follow. My eventual solution was
to take the entire email flow and have my email client do the threading.
It was much easier to follow that which was interesting to me.
Here are the top tags that have been used, you can try searching on some
of those.
#ubitx 418 threads
#ubitx-help 84 threads
#bitx40 75 threads
#bitx40help 57 threads
#parts 30 threads
#radiuno 22 threads
#bitx20help 18 threads
#w8tee 18 threads
#firmware 13 threads
#bitx20 13 threads
I read this group via email, my email client has no problem threading
messages, it also has search and filtering capabilities on a couple of
levels. I have filters, pretty much inactive now, that put certain
addresses and subjects right straight in the bit bucket. If your email
client does not have those capabilities then use the web page, you can
do searches from there.
There are related groups on groups.io as well. This is not a complete
list, just some of those that I find interesting so far.
SoftwareControlledHamRadio 1107 members 44 messages this month
HBTE (Home Brew Test Equipment) 156 members 124 messages this month
antennas 168 members 130 messages this month
And of course.
BITX20 6469 members 2524 messages this month
So this BITX20 group has lots of members and lots of messages every
month. Could some of the traffic here be spread out over some of these
other groups? Yes, and I believe that will happen over time as a couple
of those groups are less than a month old, but this will still be a busy
group and each of us will have to find strategies to deal with that.
There is no single strategy that will work for everybody. I personally
read every single message, I also follow 6 other Ham Radio related lists
and read 200 - 1000 pages of other material most days as well. But I
like to read.
Getting 6469 people to all do things a certain way is kind of like
herding cats. I think I heard that around here recently, not quite in
that context but pretty close I think.
Art N4EZZ <n4ezz@...>
GnuPG key ID 0x6712DD0E
=============================
I need a little tingle once and awhile.
WA0JYD
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On 08/28/2018 08:08 AM, ab2ts wrote: How about it? ? It is getting very hard to search and find posts just for the radio I have.
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Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
Considering the mods can't get people to stay on topic in a thread, why should it be assumed the same won't happen with subgroups? Who is going to spend the time moving topics around? Like Arv pointed out, you can mute threads.
To the guy pointing out the name of the group is bitx20, Read the group description.?
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Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
Subgroups may not be the solution that some would like.? Here is what the
help page says about subgroups. SubgroupsGroups.io supports subgroups. A subgroup is a group within another
group.
When viewing your group on the website, you can create a subgroup
by clicking
the 'Subgroup' tab on the left side. The email address of a
subgroup is of the form [email protected].Subgroups have all the functionality of normal
groups, with the
exceptions that to be a member of a subgroup, you must be a
member of
the parent group, and you cannot invite people to join subgroups.?
Once a person is a member of the parent group, they can subscribe
directly to the
subgroup if it's permitted, they can be added directly
to the subgroup, or they can
ask to join the subgroup if it is restricted. does support several methods of controlling how much email you receive, and when
that occurs.? Problem is that they do not support this being done by proxy.? Most of it only works
when you are directly logged into <>.? This means that if you are using an email
handler (gmail, hotmail, etc.) to view your email you may not have access to those tools that are
uniquely supported by .? You might want to log directly into the BITX20 group and then
configure how messages are handled with respect to your ID.? Once configured the handling
should control how messages are delivered to your email handler.? It works with gmail, but I
have not tested it with any other 3rd party email tools.
Arv
_._
From: Roy AppletonSent: ?28/?08/?2018 07:19 PMTo: [email protected]Subject: Re: [BITX20] Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?On Tue, Aug 28, 2018, 12:59 PM DuWayne Schmidlkofer < duwayne@...> wrote:
-- If there were only a couple messages a day it might make sense to keep everything together.? But I have received over 3000 digests, and it has become nearly impossible to determine which flavor BITX the messages are for.? I have a Bitx20, Bitx40 and a uBitx , it would be nice to not have to wade through all the messages and ignore the 300+ messages about End Fed antennas to find information related to my Bitx40.? ? I belong to other Groups that have sub-groups and they work well for keeping things a little more organized.
DuWayne? KV4QB
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Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
I vote for subgroups - PLEASE!
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Allison
If the IMD were "perfect" you would see two tones, period. :-)
WA8TOD
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Re: Nextion 3.2 for CEC 1.097
#ubitx
Nikos,? I do have the 3.5" Nextion display (¡.T035-011) and would love to have the files (you can send them to jlauber@...).? As for changing the x,y, h and w values, in the Nextion editor, click on any element of the display, and the Attribute page for that element pops up...scroll down to the bottom of the list and you'll find x, y, h and w and you can simply edit them.? But getting the right values to put in those is the devil in these details!
73
John
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Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
Actually all the uBITX message are NOT BITX20 related!
On August 28, 2018 at 2:45 PM Bill Bates <billy.bates@...> wrote:
From: Roy Appleton Sent: ?28/?08/?2018 07:19 PM To: [email protected] Subject: Re: [BITX20] Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?
On Tue, Aug 28, 2018, 12:59 PM DuWayne Schmidlkofer < duwayne@...> wrote:
-- If there were only a couple messages a day it might make sense to keep everything together.? But I have received over 3000 digests, and it has become nearly impossible to determine which flavor BITX the messages are for.? I have a Bitx20, Bitx40 and a uBitx , it would be nice to not have to wade through all the messages and ignore the 300+ messages about End Fed antennas to find information related to my Bitx40.? ? I belong to other Groups that have sub-groups and they work well for keeping things a little more organized.
DuWayne? KV4QB?
?
?
?
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Warren,
To that we are both in the same pew.? Bandaids are turning to cardiac surgery.
Unfortunate that that is the case.
I've gone back to modernizing a old atlas that was a parts dog for fun.
A display, Arduino, and 5351 can do a lot for that one.?
Allison
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David McGaw
