That will teach
me for DL'ing so quickly LOL.....can you post a URL to the
corrected document? 73
Gedas, W8BYA EN70JT
Light travels faster than sound.....
This is why some people appear bright until you hear them speak.
On 3/20/2025 2:30 PM, Everett N4CY via
groups.io wrote:
toggle quoted message
Show quoted text
I made the corrections that
Martin mentioned and I also add the Bias adjustment
procedure to the posting and deleted the 2 original
postings.
?
Everett N4CY
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I made the corrections that Martin mentioned and I also add the Bias adjustment procedure to the posting and deleted the 2 original postings.
?
Everett N4CY
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Re: "active antenna preamplifiers" in ham radio May 1986
Thanks Martin, I will correct it.
On Thursday, March 20, 2025, 11:45 AM, Martin - Southwest UK via groups.io <martin_ehrenfried@...> wrote: Hi Everett,
?
I think if you do this, you will have to spell out that a separate "ground" reference for the antenna and PCB needs to be provided, as the coax performs this function by default in most other designs.
?
I know it seems obvious, but many end users don't understand this significant point.
?
Regards,
?
Martin
?
?
On Wed, Mar 19, 2025 at 06:24 PM, Everett N4CY wrote:
I designed a new board that has a common mode choke on the back side of?the board,
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Re: "active antenna preamplifiers" in ham radio May 1986
toggle quoted message
Show quoted text
So we can not do attachments OR embedded graphics in the body of an email??? A picture is worth 1k words.? But I understand the cost when archived in storage.? These days, storage is the least expensive of digital options.? But I still understand.?
Today I will be attempting to make a frequency sweep of my unit.? I'll wait to upload to the files until that is complete. ?
Dave - W?LEV
On Thu, Mar 20, 2025 at 8:06?AM Martin - Southwest UK via <martin_ehrenfried= [email protected]> wrote: Yes, that's the default setting in this group, attachments are removed.
?
Dave, can you add it in the files section please.
?
Regards,
?
Martin
?
?
?
On Thu, Mar 20, 2025 at 06:47 AM, Andrea Dalbagno wrote:
It seems that the attachment has been removed from your email.
--
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Re: "active antenna preamplifiers" in ham radio May 1986
Hi Everett,
?
Incidentally, note that in your schematic, one of the input diodes, seems to have the wrong polarity.
?
Personally, I'd bias them to ensure decent IMD performance, but maybe you have already measured this using a high Z source and considered it to be OK ?
?
Regards,
?
Martin
|
Re: "active antenna preamplifiers" in ham radio May 1986
Hi Everett,
?
I think if you do this, you will have to spell out that a separate "ground" reference for the antenna and PCB needs to be provided, as the coax performs this function by default in most other designs.
?
I know it seems obvious, but many end users don't understand this significant point.
?
Regards,
?
Martin
?
?
On Wed, Mar 19, 2025 at 06:24 PM, Everett N4CY wrote:
I designed a new board that has a common mode choke on the back side of?the board,
|
Re: "active antenna preamplifiers" in ham radio May 1986
Hi Dave,
?
The free versions of IO groups, have limitations on storage. These limitations depend on the T&C's of when the group was established, the older groups have more free storage than younger groups. It was offered as an incentive to early adopters.
?
If folks include images or files in the body of their posts, it automatically gets included and stored, which counts towards the overall limit.
?
IO also reduces the resolution of images included in posts, but not when uploaded to images, and any messages that include previous posts with files or images can end up being copied multiple times.
?
By getting folks to deliberately upload to the files and photos area, only items that are likely to be of long term use get to be stored, and the more trivial items are excluded.
?
I hope this helps provide a bit of the background as to why the rules on various groups sometimes differ.
?
Regards,
?
Martin
?
On Thu, Mar 20, 2025 at 04:12 PM, W0LEV wrote:
So we can not do attachments OR embedded graphics in the body of an email???
|
Re: "active antenna preamplifiers" in ham radio May 1986
So we can not do attachments OR embedded graphics in the body of an email??? A picture is worth 1k words.? But I understand the cost when archived in storage.? These days, storage is the least expensive of digital options.? But I still understand.?
Today I will be attempting to make a frequency sweep of my unit.? I'll wait to upload to the files until that is complete. ?
Dave - W?LEV
On Thu, Mar 20, 2025 at 8:06?AM Martin - Southwest UK via <martin_ehrenfried= [email protected]> wrote:
Yes, that's the default setting in this group, attachments are removed.
?
Dave, can you add it in the files section please.
?
Regards,
?
Martin
?
?
?
On Thu, Mar 20, 2025 at 06:47 AM, Andrea Dalbagno wrote:
It seems that the attachment has been removed from your email.
|
File /Modified AMRAD eProbe Antenna.pdf uploaded
#file-notice
The following items have been added to the Files area of the [email protected] group.
By: Everett N4CY <everettsharp@...>
Description:
Active eProbe antenna
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Re: "active antenna preamplifiers" in ham radio May 1986
Mike,
?
I just uploaded it.
?
Everett N4CY
In a message dated 3/20/2025 10:44:13 AM Central Daylight Time, amdx@... writes:
?
Has the 4 FET input High Z amp schematic been posted to the files section, if so under what heading?
??????????????????? Thanks, Mikek
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Re: "active antenna preamplifiers" in ham radio May 1986
Has the 4 FET input High Z amp schematic been posted to the files section, if so under what heading?
??????????????????? Thanks, Mikek
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Re: "active antenna preamplifiers" in ham radio May 1986
Hi Henry,
?
I just quickly built one up.
?
The gain seems quite low and the IMD performance isn't that good. Current draw is about 10mA, which is quite low.
?
I need to experiment to see if I can further optimise the circuit, but it's not looking too promising.
?
When folks state things like "good strong signal handling" without providing any figures, or other parameters as evidence, it's difficult to know if a circuit is performing as expected.
?
Regards,
?
Martin
?
?
On Wed, Mar 19, 2025 at 02:30 AM, <tardivat@...> wrote:
Have you tried the G4COL design with? transformer in the FET circuit?
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Re: File /AG5RT/LZ1AQ amplifier noise reduction.pdf uploaded
#file-notice
Dear Fred
Please send both papers to me directly.? thanks in advance.
best Paul? VE3PVB
On Thursday, March 20, 2025 at 09:09:20 a.m. EDT, Fred M via groups.io <dl4zao@...> wrote:
Tell me, what you need, i have both papers available.
?
regards, Fred
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Re: File /AG5RT/LZ1AQ amplifier noise reduction.pdf uploaded
#file-notice
Tell me, what you need, i have both papers available.
?
regards, Fred
|
Re: File /AG5RT/LZ1AQ amplifier noise reduction.pdf uploaded
#file-notice
On Thu, Mar 20, 2025 at 05:15 AM, Paul V Birke wrote:
can you send me the reference directly to me
Hi Paul,
?
Is the link not working?? If not, you can search on the German word "aktiv" in the files section.? If that does not work, you can contact me directly:? mark-whittington@...?
Mark
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Re: File /AG5RT/LZ1AQ amplifier noise reduction.pdf uploaded
#file-notice
Dear Mark
can you send me the reference directly to me
thanks
Paul? VE3PVB
On Thursday, March 20, 2025 at 07:39:27 a.m. EDT, Mark Whittington AG5RT <mark-whittington@...> wrote:
On Thu, Mar 20, 2025 at 04:10 AM, Paul V Birke wrote:
Maybe that is why the original East German design had a suitable inductor in the same place
There is also this German design that uses the inductors:? ?"Aktiv empangen mit neuen Ideen" (new ideas for active reception)?
?
This may have been the inspiration for the LZ1AQ design.
?
Mark
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Re: File /AG5RT/LZ1AQ amplifier noise reduction.pdf uploaded
#file-notice
On Thu, Mar 20, 2025 at 04:10 AM, Paul V Birke wrote:
Maybe that is why the original East German design had a suitable inductor in the same place
There is also this German design that uses the inductors:? ?"Aktiv empangen mit neuen Ideen" (new ideas for active reception)?
?
This may have been the inspiration for the LZ1AQ design.
?
Mark
|
Re: File /AG5RT/LZ1AQ amplifier noise reduction.pdf uploaded
#file-notice
Complementary Push-Pull
Amplifiers for Active Antennas:
A Critical Review
by
Chris Trask / N7ZWY
Sonoran Radio Research
P.O. Box 25240
Tempe, AZ 85285-5240
Dan, this paper contains the East German KA-1000 design...please download
Paul?? VE3PVB
On Thursday, March 20, 2025 at 01:58:00 a.m. EDT, Dan Clementi <dan@...> wrote:
On Thu, Mar 20, 2025 at 12:28 AM, Paul V Birke wrote:
Maybe that is why the original East German design had a suitable inductor in the same place
East German???? To what are you referring?
As far as I am aware, the LZ1AQ loop amplifier is this one:
?
Dan - K3GMQ
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Re: File /AG5RT/LZ1AQ amplifier noise reduction.pdf uploaded
#file-notice
On Thursday, March 20, 2025 at 01:58:00 a.m. EDT, Dan Clementi <dan@...> wrote:
On Thu, Mar 20, 2025 at 12:28 AM, Paul V Birke wrote:
Maybe that is why the original East German design had a suitable inductor in the same place
East German???? To what are you referring?
As far as I am aware, the LZ1AQ loop amplifier is this one:
?
Dan - K3GMQ
|
Re: "active antenna preamplifiers" in ham radio May 1986
Thank you, Martin.
73 Andrea IN3IWZ?
Il gio 20 mar 2025, 09:06 Martin - Southwest UK via <martin_ehrenfried= [email protected]> ha scritto: Yes, that's the default setting in this group, attachments are removed.
?
Dave, can you add it in the files section please.
?
Regards,
?
Martin
?
?
?
On Thu, Mar 20, 2025 at 06:47 AM, Andrea Dalbagno wrote:
It seems that the attachment has been removed from your email.
|
Everett N4CY