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.
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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
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
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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
toggle quoted message
Show quoted text
-----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
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Show quoted text
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.
toggle quoted message
Show quoted text
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
toggle quoted message
Show quoted text
-----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
toggle quoted message
Show quoted text
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
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
toggle quoted message
Show quoted text
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=26265873 -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
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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
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-----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
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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.
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On Wednesday, March 6th, 2024 at 11:49 AM, Greg W?GUS <w.zero.gus@...> wrote:
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Thanks Steve!? I wonder who figured out the crystal baking trick?!?!
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Re: AC Switches for 4 Line Twins
This might help.? Has anyone used this place???
73 Steve WA8ZMC
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Re: Drake L7 Power output
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"
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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
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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
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