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Re: Drake L7 Power output

 

I remember these ads really well, and vaguely recall this (from one of the ads you posted)



Anyone recall how long it ran with the brick on the key?

John K5MO


Re: Drake SL-2300 2.3-5645kHz Filter Testing

 

Thanks, Jim. A lot of these gadgets aren't as useer-friendly to me as an ol' sweeper and scope.

I bought up an estate a few years ago and had two of those BY HT's. I guess you have to load software from your PC to even enter a frequency. I sold them and kept my Yaesu FT-470 :-)



Steve Wedge, W1ES/4

Time flies like an arrow.? Fruit flies like a banana.

Sent with Proton Mail secure email.

On Wednesday, March 6th, 2024 at 5:37 PM, Jim Shorney <jimNU0C@...> wrote:

You are mainly interested in S21 logmag. You will want to do a calibration centered on 5.645 MHz with probably 30 KHz or so span. You can set your stimulus centered on 5.645 using Center/Span settings. Turn off all but one of the traces, and set the trace for format S21 Thru > LOGMAG. Connect the filter between the two ports with very short coax pigtails and you should see a nice picture. You can very the width of the sweep by changing the Stimulus Span. I was thinking that the firmware might have the ability to print the filter bandwidth parameters but I may be thinking of the Midnight SNA. You can dive deeper with the NanoVNA-app or nanovna-saver software. If you want to save screen shots you need software. NanoVNA-app is probably best for beginners. You need to jump through some hoops to get nanovna-saver running on Windows or Linux.


My TinySA shows about -10 dBm out of the NVNA at 5.645 MHz so it should be plenty safe.

You can also measure return loss other parameters if you want to get more advanced but this will get you started. There has been a fair amount of discussion in the NanoVNA group about this also.

73

-Jim
NU)C

On Wed, 06 Mar 2024 14:01:49 -0800
"Steve Wedge, W1ES/4 via groups.io" w1es@... wrote:

I¡¯ve been having trouble trying to figure out how to set up the NVNA to check filters. I¡¯ve found nothing really online. Any suggestions? Those menus are a challenge to me.

Steve Wedge, W1ES/4

Time flies like an arrow. Fruit flies like a banana.

Sent from Proton Mail for iOS

On Wed, Mar 6, 2024 at 15:48, Jim Shorney <[jimNU0C@...](mailto:On Wed, Mar 6, 2024 at 15:48, Jim Shorney <<a href=)> wrote:

We'll try this again, without the fat figered ENTER key...

Not particularly. I used the raw output of my NanoVNA-H and Midnight SNA. I would have to dig up what those values are.

This does not answer your question but I posted a bunch of 7-Line NVNA sweeps here:

/g/DRAKE-RADIO/album?id=262658

73

-Jim
NU0C

On Wed, 06 Mar 2024 12:21:32 -0800
"Jerry Kessler" N4JL.cw@... wrote:

Jim,

Any guidance as to maximum signal level for sweeping these Drake filters?

Thanks,

Jerry, N4JL

-----Original Message-----
From: [email protected] [email protected] On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 12:22 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake SL-2300 2.3-5645kHz Filter Testing

Wes,

Comments inline below.

On Wed, 06 Mar 2024 07:03:50 -0800
"Wes Winkler via groups.io" wewinkler@... wrote:

I got a couple of Drake SL-2300 2.3-5645kHz Filters at a swap meet and am
contemplating testing them with a NanoVNA. I have three concerns.

1) Can I directly connect the filter to the Nano VNA? I am mainly
concerned about damaging the filter due to the signal input signal level.
Yes. I have done it with several TR7 filters with both a NVNA and a Midnight
SNA. They both agree closely with sweeps done with two different HP 8594E
spectrum analyzers with the tracking generator option. You could use an
inline 50 Ohm attenuator on the NVNA output if you are really worried about
the signal level but I have had no issues.

2) I reviewed the TR-7 manual but it not immediately obvious which is the
input, and which is the output of the filter.
The filters are symmetrical. It doesn't matter. If you really want to know
you can trace the signal path on the block diagram and the schematics to
figure out which port is which by visually inspecting the filter board.

3) An idea of what the input/output impedance termination should be? I
may need matching transformers for the Nano VNA test.
50 Ohms. You can directly connect to the NVNA.

Attached are some samples done within the past couple of months of NOS eBay
filters. One is a screen cap of an Inrad 4 KHz, the other two are sweeps of
a late production Drake labeled SL2300 done with nanovna-saver software in
Linux.

You can also bench test the filters from your radio without taking them off
the filter board. All you need is a source of around 10 volts to activate
the filter you want to test and a source of -4 or so to bias off the unused
filters. I used by bench supply for the + voltage and a 18650 lithium-ion
cell for the - voltage.

73

-Jim
NU0C
--

73

-Jim
NU0C



--

73

-Jim
NU0C



Re: AC Switches for 4 Line Twins

 

¿ªÔÆÌåÓý

I have.?

Mark has a very extensive collection of potentiometers. He was able to provide me with a brand-new two-gang pot with on-off switch, with a tap on one of the pots and with a custom-length shaft, for a 1936 RCA console radio. It was fairly expensive, about $30 about 10 years ago, but it brought the radio back to life in perfect condition. There is no way I would have found another source.

73,
Graham N6GH





On Mar 6, 2024, at 10:45?AM, Steve Kessler <wpe8jvi@...> wrote:

?This might help.? Has anyone used this place???

73
Steve WA8ZMC


Re: Drake L7 Power output

 

I am most interested in the era of the 76 and 77.

73

-Jim
NU0C

On Wed, 06 Mar 2024 14:12:49 -0800
"Paul Christensen" <w9ac@...> wrote:

In total, I have 63 of their ads saved that span a time from 1970 through
about 2000.

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 5:03 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake L7 Power output


Thanks Paul. I've been meaning to look for some of those. My small Alpha is
a 76.

73

-Jim
NU0C

On Wed, 06 Mar 2024 13:23:38 -0800
"Paul Christensen" <w9ac@...> wrote:

Here are a few ETO/Alpha ads on my Google Drive with the legendary
brick on the key. Don't do this with today's solid-state amps.


?usp=s
haring

?usp=s
haring

?usp=s
haring

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim
Shorney
Sent: Wednesday, March 6, 2024 12:30 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake L7 Power output


Oh yeah. Looking at my 77Sx I believe it.

73

-Jim
NU0C

On Wed, 06 Mar 2024 09:11:01 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-03-06 08:47, Jim Shorney wrote:

I have a couple of Alphas that would do that but my antenna would
complain.
*** Remember the Alpha advertisement with the brick on the code key?

- Jerry, KF6VB










--

73

-Jim
NU0C


Re: Drake SL-2300 2.3-5645kHz Filter Testing

 

You are mainly interested in S21 logmag. You will want to do a calibration centered on 5.645 MHz with probably 30 KHz or so span. You can set your stimulus centered on 5.645 using Center/Span settings. Turn off all but one of the traces, and set the trace for format S21 Thru > LOGMAG. Connect the filter between the two ports with very short coax pigtails and you should see a nice picture. You can very the width of the sweep by changing the Stimulus Span. I was thinking that the firmware might have the ability to print the filter bandwidth parameters but I may be thinking of the Midnight SNA. You can dive deeper with the NanoVNA-app or nanovna-saver software. If you want to save screen shots you need software. NanoVNA-app is probably best for beginners. You need to jump through some hoops to get nanovna-saver running on Windows or Linux.

My TinySA shows about -10 dBm out of the NVNA at 5.645 MHz so it should be plenty safe.

You can also measure return loss other parameters if you want to get more advanced but this will get you started. There has been a fair amount of discussion in the NanoVNA group about this also.

73

-Jim
NU)C

On Wed, 06 Mar 2024 14:01:49 -0800
"Steve Wedge, W1ES/4 via groups.io" <w1es@...> wrote:

I¡¯ve been having trouble trying to figure out how to set up the NVNA to check filters. I¡¯ve found nothing really online. Any suggestions? Those menus are a challenge to me.

Steve Wedge, W1ES/4

Time flies like an arrow. Fruit flies like a banana.

Sent from [Proton Mail]() for iOS

On Wed, Mar 6, 2024 at 15:48, Jim Shorney <[jimNU0C@...](mailto:On Wed, Mar 6, 2024 at 15:48, Jim Shorney <<a href=)> wrote:

We'll try this again, without the fat figered ENTER key...

Not particularly. I used the raw output of my NanoVNA-H and Midnight SNA. I would have to dig up what those values are.

This does not answer your question but I posted a bunch of 7-Line NVNA sweeps here:

/g/DRAKE-RADIO/album?id=262658

73

-Jim
NU0C

On Wed, 06 Mar 2024 12:21:32 -0800
"Jerry Kessler" <N4JL.cw@...> wrote:

Jim,

Any guidance as to maximum signal level for sweeping these Drake filters?

Thanks,

Jerry, N4JL

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 12:22 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake SL-2300 2.3-5645kHz Filter Testing


Wes,

Comments inline below.

On Wed, 06 Mar 2024 07:03:50 -0800
"Wes Winkler via groups.io" <wewinkler@...> wrote:

I got a couple of Drake SL-2300 2.3-5645kHz Filters at a swap meet and am
contemplating testing them with a NanoVNA. I have three concerns.

1) Can I directly connect the filter to the Nano VNA? I am mainly
concerned about damaging the filter due to the signal input signal level.

Yes. I have done it with several TR7 filters with both a NVNA and a Midnight
SNA. They both agree closely with sweeps done with two different HP 8594E
spectrum analyzers with the tracking generator option. You could use an
inline 50 Ohm attenuator on the NVNA output if you are really worried about
the signal level but I have had no issues.

2) I reviewed the TR-7 manual but it not immediately obvious which is the
input, and which is the output of the filter.

The filters are symmetrical. It doesn't matter. If you really want to know
you can trace the signal path on the block diagram and the schematics to
figure out which port is which by visually inspecting the filter board.

3) An idea of what the input/output impedance termination should be? I
may need matching transformers for the Nano VNA test.

50 Ohms. You can directly connect to the NVNA.

Attached are some samples done within the past couple of months of NOS eBay
filters. One is a screen cap of an Inrad 4 KHz, the other two are sweeps of
a late production Drake labeled SL2300 done with nanovna-saver software in
Linux.

You can also bench test the filters from your radio without taking them off
the filter board. All you need is a source of around 10 volts to activate
the filter you want to test and a source of -4 or so to bias off the unused
filters. I used by bench supply for the + voltage and a 18650 lithium-ion
cell for the - voltage.

73

-Jim
NU0C










--

73

-Jim
NU0C





--

73

-Jim
NU0C


Re: Drake L7 Power output

 

In total, I have 63 of their ads saved that span a time from 1970 through
about 2000.

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 5:03 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake L7 Power output


Thanks Paul. I've been meaning to look for some of those. My small Alpha is
a 76.

73

-Jim
NU0C

On Wed, 06 Mar 2024 13:23:38 -0800
"Paul Christensen" <w9ac@...> wrote:

Here are a few ETO/Alpha ads on my Google Drive with the legendary
brick on the key. Don't do this with today's solid-state amps.


?usp=s
haring

?usp=s
haring

?usp=s
haring

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim
Shorney
Sent: Wednesday, March 6, 2024 12:30 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake L7 Power output


Oh yeah. Looking at my 77Sx I believe it.

73

-Jim
NU0C

On Wed, 06 Mar 2024 09:11:01 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-03-06 08:47, Jim Shorney wrote:

I have a couple of Alphas that would do that but my antenna would
complain.
*** Remember the Alpha advertisement with the brick on the code key?

- Jerry, KF6VB


Re: Drake L7 Power output

 

Easy on that Brown Brothers key!? :-)

John K5MO


On Wed, Mar 6, 2024 at 5:03?PM Jim Shorney <jimNU0C@...> wrote:

Thanks Paul. I've been meaning to look for some of those. My small Alpha is a 76.

73

-Jim
NU0C

On Wed, 06 Mar 2024 13:23:38 -0800
"Paul Christensen" <w9ac@...> wrote:

> Here are a few ETO/Alpha ads on my Google Drive with the legendary brick on
> the key.? Don't do this with today's solid-state amps.
>
>
> haring
>
> haring
>
> haring
>
> Paul, W9AC
>
> -----Original Message-----
> From: [email protected] <[email protected]> On Behalf Of Jim Shorney
> Sent: Wednesday, March 6, 2024 12:30 PM
> To: [email protected]
> Subject: Re: [DRAKE-RADIO] Drake L7 Power output
>
>
> Oh yeah. Looking at my 77Sx I believe it.
>
> 73
>
> -Jim
> NU0C
>
> On Wed, 06 Mar 2024 09:11:01 -0800
> "jerry-KF6VB" <jerry@...> wrote:
>
> > On 2024-03-06 08:47, Jim Shorney wrote:
> >? ?
> > > I have a couple of Alphas that would do that but my antenna would
> > > complain.?
> >
> > *** Remember the Alpha advertisement with the brick on the code key?
> >
> >? ? ? ? ? ? ? ? ? ?- Jerry, KF6VB?






Re: Drake L7 Power output

 

Thanks Paul. I've been meaning to look for some of those. My small Alpha is a 76.

73

-Jim
NU0C

On Wed, 06 Mar 2024 13:23:38 -0800
"Paul Christensen" <w9ac@...> wrote:

Here are a few ETO/Alpha ads on my Google Drive with the legendary brick on
the key. Don't do this with today's solid-state amps.


haring

haring

haring

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 12:30 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake L7 Power output


Oh yeah. Looking at my 77Sx I believe it.

73

-Jim
NU0C

On Wed, 06 Mar 2024 09:11:01 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-03-06 08:47, Jim Shorney wrote:

I have a couple of Alphas that would do that but my antenna would
complain.
*** Remember the Alpha advertisement with the brick on the code key?

- Jerry, KF6VB


Re: Drake SL-2300 2.3-5645kHz Filter Testing

 

I¡¯ve been having trouble trying to figure out how to set up the NVNA to check filters. I¡¯ve found nothing really online. Any suggestions? ?Those menus are a challenge to me.?

Steve Wedge, W1ES/4

Time flies like an arrow. Fruit flies like a banana.


Sent from for iOS


On Wed, Mar 6, 2024 at 15:48, Jim Shorney <jimNU0C@...> wrote:

We'll try this again, without the fat figered ENTER key...

Not particularly. I used the raw output of my NanoVNA-H and Midnight SNA. I would have to dig up what those values are.

This does not answer your question but I posted a bunch of 7-Line NVNA sweeps here:

/g/DRAKE-RADIO/album?id=262658

73

-Jim
NU0C


On Wed, 06 Mar 2024 12:21:32 -0800
"Jerry Kessler" <N4JL.cw@...> wrote:

> Jim,
>
> Any guidance as to maximum signal level for sweeping these Drake filters?
>
> Thanks,
>
> Jerry, N4JL
>
> -----Original Message-----
> From: [email protected] <[email protected]> On Behalf Of Jim Shorney
> Sent: Wednesday, March 6, 2024 12:22 PM
> To: [email protected]
> Subject: Re: [DRAKE-RADIO] Drake SL-2300 2.3-5645kHz Filter Testing
>
>
> Wes,
>
> Comments inline below.
>
> On Wed, 06 Mar 2024 07:03:50 -0800
> "Wes Winkler via groups.io" <wewinkler@...> wrote:
>
> > I got a couple of Drake SL-2300 2.3-5645kHz Filters at a swap meet and am
> contemplating testing them with a NanoVNA. I have three concerns.
> >
> > 1) Can I directly connect the filter to the Nano VNA? I am mainly
> concerned about damaging the filter due to the signal input signal level.
>
> Yes. I have done it with several TR7 filters with both a NVNA and a Midnight
> SNA. They both agree closely with sweeps done with two different HP 8594E
> spectrum analyzers with the tracking generator option. You could use an
> inline 50 Ohm attenuator on the NVNA output if you are really worried about
> the signal level but I have had no issues.
>
> > 2) I reviewed the TR-7 manual but it not immediately obvious which is the
> input, and which is the output of the filter.
>
> The filters are symmetrical. It doesn't matter. If you really want to know
> you can trace the signal path on the block diagram and the schematics to
> figure out which port is which by visually inspecting the filter board.
>
> > 3) An idea of what the input/output impedance termination should be? I
> may need matching transformers for the Nano VNA test.
>
> 50 Ohms. You can directly connect to the NVNA.
>
> Attached are some samples done within the past couple of months of NOS eBay
> filters. One is a screen cap of an Inrad 4 KHz, the other two are sweeps of
> a late production Drake labeled SL2300 done with nanovna-saver software in
> Linux.
>
> You can also bench test the filters from your radio without taking them off
> the filter board. All you need is a source of around 10 volts to activate
> the filter you want to test and a source of -4 or so to bias off the unused
> filters. I used by bench supply for the + voltage and a 18650 lithium-ion
> cell for the - voltage.
>
> 73
>
> -Jim
> NU0C
>
>
>
>
>
>
>
>
>
>
>



--

73

-Jim
NU0C






Re: Drake L7 Power output

 

FT8 is a continuous carrier mode. True that it is MFSK, but there is only ONE tone present at any given time. This has been explained many times by the developers and Joe Taylor himself in various WSJTX forums. You can treat it like CW for PEP measurement. It is the duty cycle that can kill. That's why I like the TR7. I can run full power FT/JT all day and it handles it well.

73

-Jim
NU0C

On Wed, 06 Mar 2024 13:07:06 -0800
"Dudley (WA5QPZ)" <jhurry@...> wrote:

To get that kind of power out, I am sure the driver rig is beyond its pro limits , since FT8 is a accumulated pep mode, ? Most 100 watt pep should only be run at 1/2 power, or 50 watts out

73,
Dudley
WA5QPZ



On Mar 6, 2024, at 11:52?AM, Mike Bryce <prosolar@...> wrote:

?I always wanted to know what they used as an exciter.

Mike Bryce WB8VGE
prosolar@...

"The eye is always caught?by the light, but shadows?have more to say"


On Mar 6, 2024, at 12:30 PM, Jim Shorney <jimNU0C@...> wrote:


Oh yeah. Looking at my 77Sx I believe it.

73

-Jim
NU0C

On Wed, 06 Mar 2024 09:11:01 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-03-06 08:47, Jim Shorney wrote:

I have a couple of Alphas that would do that but my antenna would
complain. ?
*** Remember the Alpha advertisement with the brick on the code key?

?????????????????- Jerry, KF6VB








--

73

-Jim
NU0C


Re: Drake SL-2300 2.3-5645kHz Filter Testing

 

Thanks for the info Rob. I will add it to my notes.

73

-Jim
NU0C

On Wed, 06 Mar 2024 13:10:23 -0800
"Rob Sherwood" <rob@...> wrote:

Insertion loss can change a bit with the drive level which is more likely with CW bandwidths. An SSB filter loss should be under 4 dB at a -10 dBm level. A 250 Hz filter may have 10 dB insertion loss. I do not recommend driving filters over +10 dBm.

Rob, NC0B
On Mar 6, 2024, at 1:23?PM, Jerry Kessler <N4JL.cw@...> wrote:

?Jim,

Any guidance as to maximum signal level for sweeping these Drake filters?

Thanks,

Jerry, N4JL

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 12:22 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake SL-2300 2.3-5645kHz Filter Testing


Wes,

Comments inline below.

On Wed, 06 Mar 2024 07:03:50 -0800
"Wes Winkler via groups.io" <wewinkler@...> wrote:

I got a couple of Drake SL-2300 2.3-5645kHz Filters at a swap meet and am
contemplating testing them with a NanoVNA. I have three concerns.

1) Can I directly connect the filter to the Nano VNA? I am mainly
concerned about damaging the filter due to the signal input signal level.

Yes. I have done it with several TR7 filters with both a NVNA and a Midnight
SNA. They both agree closely with sweeps done with two different HP 8594E
spectrum analyzers with the tracking generator option. You could use an
inline 50 Ohm attenuator on the NVNA output if you are really worried about
the signal level but I have had no issues.

2) I reviewed the TR-7 manual but it not immediately obvious which is the
input, and which is the output of the filter.

The filters are symmetrical. It doesn't matter. If you really want to know
you can trace the signal path on the block diagram and the schematics to
figure out which port is which by visually inspecting the filter board.

3) An idea of what the input/output impedance termination should be? I
may need matching transformers for the Nano VNA test.

50 Ohms. You can directly connect to the NVNA.

Attached are some samples done within the past couple of months of NOS eBay
filters. One is a screen cap of an Inrad 4 KHz, the other two are sweeps of
a late production Drake labeled SL2300 done with nanovna-saver software in
Linux.

You can also bench test the filters from your radio without taking them off
the filter board. All you need is a source of around 10 volts to activate
the filter you want to test and a source of -4 or so to bias off the unused
filters. I used by bench supply for the + voltage and a 18650 lithium-ion
cell for the - voltage.

73

-Jim
NU0C















--

73

-Jim
NU0C


Re: Drake L7 Power output

 

Here are a few ETO/Alpha ads on my Google Drive with the legendary brick on
the key. Don't do this with today's solid-state amps.


haring

haring

haring

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 12:30 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake L7 Power output


Oh yeah. Looking at my 77Sx I believe it.

73

-Jim
NU0C

On Wed, 06 Mar 2024 09:11:01 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-03-06 08:47, Jim Shorney wrote:

I have a couple of Alphas that would do that but my antenna would
complain.
*** Remember the Alpha advertisement with the brick on the code key?

- Jerry, KF6VB


Re: Drake SL-2300 2.3-5645kHz Filter Testing

 

Insertion loss can change a bit with the drive level which is more likely with CW bandwidths. An SSB filter loss should be under 4 dB at a -10 dBm level. A 250 Hz filter may have 10 dB insertion loss. I do not recommend driving filters over +10 dBm.

Rob, NC0B

On Mar 6, 2024, at 1:23?PM, Jerry Kessler <N4JL.cw@...> wrote:

?Jim,

Any guidance as to maximum signal level for sweeping these Drake filters?

Thanks,

Jerry, N4JL

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 12:22 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake SL-2300 2.3-5645kHz Filter Testing


Wes,

Comments inline below.

On Wed, 06 Mar 2024 07:03:50 -0800
"Wes Winkler via groups.io" <wewinkler@...> wrote:

I got a couple of Drake SL-2300 2.3-5645kHz Filters at a swap meet and am
contemplating testing them with a NanoVNA. I have three concerns.

1) Can I directly connect the filter to the Nano VNA? I am mainly
concerned about damaging the filter due to the signal input signal level.

Yes. I have done it with several TR7 filters with both a NVNA and a Midnight
SNA. They both agree closely with sweeps done with two different HP 8594E
spectrum analyzers with the tracking generator option. You could use an
inline 50 Ohm attenuator on the NVNA output if you are really worried about
the signal level but I have had no issues.

2) I reviewed the TR-7 manual but it not immediately obvious which is the
input, and which is the output of the filter.

The filters are symmetrical. It doesn't matter. If you really want to know
you can trace the signal path on the block diagram and the schematics to
figure out which port is which by visually inspecting the filter board.

3) An idea of what the input/output impedance termination should be? I
may need matching transformers for the Nano VNA test.

50 Ohms. You can directly connect to the NVNA.

Attached are some samples done within the past couple of months of NOS eBay
filters. One is a screen cap of an Inrad 4 KHz, the other two are sweeps of
a late production Drake labeled SL2300 done with nanovna-saver software in
Linux.

You can also bench test the filters from your radio without taking them off
the filter board. All you need is a source of around 10 volts to activate
the filter you want to test and a source of -4 or so to bias off the unused
filters. I used by bench supply for the + voltage and a 18650 lithium-ion
cell for the - voltage.

73

-Jim
NU0C











Re: Drake L7 Power output

 

¿ªÔÆÌåÓý

To get that kind of power out, I am sure the driver rig is beyond its pro limits , since FT8 is a accumulated pep mode, ? Most 100 watt pep should only be run at 1/2 power, or 50 watts out

73,
Dudley
WA5QPZ



On Mar 6, 2024, at 11:52?AM, Mike Bryce <prosolar@...> wrote:

?I always wanted to know what they used as an exciter.

Mike Bryce WB8VGE

"The eye is always caught?by the light, but shadows?have more to say"


On Mar 6, 2024, at 12:30 PM, Jim Shorney <jimNU0C@...> wrote:


Oh yeah. Looking at my 77Sx I believe it.

73

-Jim
NU0C

On Wed, 06 Mar 2024 09:11:01 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-03-06 08:47, Jim Shorney wrote:

I have a couple of Alphas that would do that but my antenna would
complain. ?

*** Remember the Alpha advertisement with the brick on the code key?

?????????????????- Jerry, KF6VB










Re: Drake SL-2300 2.3-5645kHz Filter Testing

 

We'll try this again, without the fat figered ENTER key...

Not particularly. I used the raw output of my NanoVNA-H and Midnight SNA. I would have to dig up what those values are.

This does not answer your question but I posted a bunch of 7-Line NVNA sweeps here:

/g/DRAKE-RADIO/album?id=262658

73

-Jim
NU0C


On Wed, 06 Mar 2024 12:21:32 -0800
"Jerry Kessler" <N4JL.cw@...> wrote:

Jim,

Any guidance as to maximum signal level for sweeping these Drake filters?

Thanks,

Jerry, N4JL

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 12:22 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake SL-2300 2.3-5645kHz Filter Testing


Wes,

Comments inline below.

On Wed, 06 Mar 2024 07:03:50 -0800
"Wes Winkler via groups.io" <wewinkler@...> wrote:

I got a couple of Drake SL-2300 2.3-5645kHz Filters at a swap meet and am
contemplating testing them with a NanoVNA.? I have three concerns.

1) Can I directly connect the filter to the Nano VNA? I am mainly
concerned about damaging the filter due to the signal input signal level.

Yes. I have done it with several TR7 filters with both a NVNA and a Midnight
SNA. They both agree closely with sweeps done with two different HP 8594E
spectrum analyzers with the tracking generator option. You could use an
inline 50 Ohm attenuator on the NVNA output if you are really worried about
the signal level but I have had no issues.

2) I reviewed the TR-7 manual but it not immediately obvious which is the
input, and which is the output of the filter.

The filters are symmetrical. It doesn't matter. If you really want to know
you can trace the signal path on the block diagram and the schematics to
figure out which port is which by visually inspecting the filter board.

3) An idea of what the input/output impedance termination should be?? I
may need matching transformers for the Nano VNA test.

50 Ohms. You can directly connect to the NVNA.

Attached are some samples done within the past couple of months of NOS eBay
filters. One is a screen cap of an Inrad 4 KHz, the other two are sweeps of
a late production Drake labeled SL2300 done with nanovna-saver software in
Linux.

You can also bench test the filters from your radio without taking them off
the filter board. All you need is a source of around 10 volts to activate
the filter you want to test and a source of -4 or so to bias off the unused
filters. I used by bench supply for the + voltage and a 18650 lithium-ion
cell for the - voltage.

73

-Jim
NU0C












--

73

-Jim
NU0C


Re: Drake SL-2300 2.3-5645kHz Filter Testing

 

Jim,

Any guidance as to maximum signal level for sweeping these Drake filters?

Thanks,

Jerry, N4JL

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Wednesday, March 6, 2024 12:22 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake SL-2300 2.3-5645kHz Filter Testing


Wes,

Comments inline below.

On Wed, 06 Mar 2024 07:03:50 -0800
"Wes Winkler via groups.io" <wewinkler@...> wrote:

I got a couple of Drake SL-2300 2.3-5645kHz Filters at a swap meet and am
contemplating testing them with a NanoVNA.? I have three concerns.

1) Can I directly connect the filter to the Nano VNA? I am mainly
concerned about damaging the filter due to the signal input signal level.

Yes. I have done it with several TR7 filters with both a NVNA and a Midnight
SNA. They both agree closely with sweeps done with two different HP 8594E
spectrum analyzers with the tracking generator option. You could use an
inline 50 Ohm attenuator on the NVNA output if you are really worried about
the signal level but I have had no issues.

2) I reviewed the TR-7 manual but it not immediately obvious which is the
input, and which is the output of the filter.

The filters are symmetrical. It doesn't matter. If you really want to know
you can trace the signal path on the block diagram and the schematics to
figure out which port is which by visually inspecting the filter board.

3) An idea of what the input/output impedance termination should be?? I
may need matching transformers for the Nano VNA test.

50 Ohms. You can directly connect to the NVNA.

Attached are some samples done within the past couple of months of NOS eBay
filters. One is a screen cap of an Inrad 4 KHz, the other two are sweeps of
a late production Drake labeled SL2300 done with nanovna-saver software in
Linux.

You can also bench test the filters from your radio without taking them off
the filter board. All you need is a source of around 10 volts to activate
the filter you want to test and a source of -4 or so to bias off the unused
filters. I used by bench supply for the + voltage and a 18650 lithium-ion
cell for the - voltage.

73

-Jim
NU0C


Re: T4X-B no transmit on 75 and 160

 

I heard it from somewhere and shared it with this group but I can't remember who told me.? There is somebody in this group with the physics background who explained why it works.? It has something to do with microscopic coatings on the quartz and "boiling" them off in the oven.

Steve Wedge, W1ES/4

Time flies like an arrow.? Fruit flies like a banana.

Sent with secure email.

On Wednesday, March 6th, 2024 at 11:49 AM, Greg W?GUS <w.zero.gus@...> wrote:

Thanks Steve!? I wonder who figured out the crystal baking trick?!?!


Re: AC Switches for 4 Line Twins

 

This might help.? Has anyone used this place???

73
Steve WA8ZMC


Re: Drake L7 Power output

 

¿ªÔÆÌåÓý

I always wanted to know what they used as an exciter.

Mike Bryce WB8VGE

"The eye is always caught?by the light, but shadows?have more to say"


On Mar 6, 2024, at 12:30 PM, Jim Shorney <jimNU0C@...> wrote:


Oh yeah. Looking at my 77Sx I believe it.

73

-Jim
NU0C

On Wed, 06 Mar 2024 09:11:01 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-03-06 08:47, Jim Shorney wrote:

I have a couple of Alphas that would do that but my antenna would
complain. ?

*** Remember the Alpha advertisement with the brick on the code key?

?????????????????- Jerry, KF6VB










Re: Drake L7 Power output

 

Oh yeah. Looking at my 77Sx I believe it.

73

-Jim
NU0C

On Wed, 06 Mar 2024 09:11:01 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-03-06 08:47, Jim Shorney wrote:

I have a couple of Alphas that would do that but my antenna would
complain.
*** Remember the Alpha advertisement with the brick on the code key?

- Jerry, KF6VB