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Locked File /FET Follower Project.pdf uploaded #file-notice

Group Notification
 

The following files and folders have been uploaded to the Files area of the [email protected] group.

By: Everett N4CY <everettsharp@...>

Description:
This is info on the board that I designed for the Lankford FET Follower
 

On Fri, Mar 3, 2023 at 07:57 AM, "Group Notification" <[email protected]> wrote:

The following files and folders have been uploaded to the Files area of the [email protected] group.

By: Everett N4CY <everettsharp@...>

Description:
This is info on the board that I designed for the Lankford FET Follower


J310's in TO-92 are hard to find and J271 is obsolete by Mouser still has stock of both but at 10x the price of the drawing. .? What is the size of the capacitor marked 1 in the drawing ?? 1 pF, 1 nF or 1uF?

Roger
 

1uF

In a message dated 3/3/2023 10:26:51 AM Central Standard Time, sailtamarack@... writes:
?

On Fri, Mar 3, 2023 at 07:57 AM, "Group Notification" <[email protected]> wrote:

The following files and folders have been uploaded to the Files area of the [email protected] group.

By: Everett N4CY <everettsharp@...>

Description:
This is info on the board that I designed for the Lankford FET Follower


J310's in TO-92 are hard to find and J271 is obsolete by Mouser still has stock of both but at 10x the price of the drawing. .? What is the size of the capacitor marked 1 in the drawing ?? 1 pF, 1 nF or 1uF?

Roger

 

Hi Everett,
?I'm curious about the 50Ω output impedance, Dallas always said it was close to 100Ω output and you have a 1 to1 output transformer.
I have a couple 2 FET amps, When I get some time I'll test them. I'm busy trying to learn Arduino code and write a sketch for it.
???????????????????????????????????? Mikek
 

Mikek,

Most people use 50 ohms these days, so all of my designs are using?50 ohms.

Everett





On Friday, March 3, 2023, 11:03 AM, Mikek <amdx@...> wrote:

Hi Everett,
?I'm curious about the 50Ω output impedance, Dallas always said it was close to 100Ω output and you have a 1 to1 output transformer.
I have a couple 2 FET amps, When I get some time I'll test them. I'm busy trying to learn Arduino code and write a sketch for it.
???????????????????????????????????? Mikek

 

On Fri, Mar 3, 2023 at 09:40 AM, Everett N4CY wrote:
Most people use 50 ohms these days, so all of my designs are using?50 ohms.

?I understand 50Ω and sometimes 75Ω are standards for common coax cable.
?For phased wiring of receive antennas, ingress must be kept as close to zero as possible,
?twisted pairs (or Cat5/6) are good at that, and they are about 100Ωs impedance.
The reason I brought it up is because, I thought I'd read something Dallas wrote saying,
the output impedance of the 2 FET Amp was close 100Ω.
?Just curious, I guess I should take the time to investigate the ones I built.
???????????????????????????????????????????????????? Mikek
 

On Sat, Mar 4, 2023 at 05:34 AM, Mikek wrote:
On Fri, Mar 3, 2023 at 09:40 AM, Everett N4CY wrote:
Most people use 50 ohms these days, so all of my designs are using?50 ohms.

?I understand 50Ω and sometimes 75Ω are standards for common coax cable.
?For phased wiring of receive antennas, ingress must be kept as close to zero as possible,
?twisted pairs (or Cat5/6) are good at that, and they are about 100Ωs impedance.
The reason I brought it up is because, I thought I'd read something Dallas wrote saying,
the output impedance of the 2 FET Amp was close 100Ω.
?Just curious, I guess I should take the time to investigate the ones I built.
???????????????????????????????????????????????????? Mikek
IIRC Dallas liked twisted pair because he found it has less noise pickup than coax.?

Roger
 

Roger,

You can get better results using a FT240-75 toroid with 25 turns of RG316 coax.

Everett




On Saturday, March 4, 2023, 11:46 AM, Roger Need via groups.io <sailtamarack@...> wrote:

On Sat, Mar 4, 2023 at 05:34 AM, Mikek wrote:
On Fri, Mar 3, 2023 at 09:40 AM, Everett N4CY wrote:
Most people use 50 ohms these days, so all of my designs are using?50 ohms.

?I understand 50Ω and sometimes 75Ω are standards for common coax cable.
?For phased wiring of receive antennas, ingress must be kept as close to zero as possible,
?twisted pairs (or Cat5/6) are good at that, and they are about 100Ωs impedance.
The reason I brought it up is because, I thought I'd read something Dallas wrote saying,
the output impedance of the 2 FET Amp was close 100Ω.
?Just curious, I guess I should take the time to investigate the ones I built.
???????????????????????????????????????????????????? Mikek
IIRC Dallas liked twisted pair because he found it has less noise pickup than coax.?

Roger

 

Or

Cat5e ( external use, solid copper not cheap crap) with common mode chokes fitted..ala LZ1AQ ( what i use, what a difference they make!!!)

If done properly, turn preamp off zero pickup, ( assuming you common mode choked your mains power, pc leads, tx antennas ( so don’t re radiate noise,) etc, which obviously you have done.

Simon g0zen

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