开云体育

ctrl + shift + ? for shortcuts
© 2025 Groups.io

Drake L7 10m modification


 

I just finished modifying my Drake L7 to operate on 10m.
I have been reading articles on line regarding this modification and was puzzled as to why adding a 68pf capacitor to the “L4 15m input coil” would be part of the 10m modification.
The 15m coil isn’t even accessed using the 10m band switch.
After studying the schematic and verifying the actual band switch wiring I came to the conclusion that C6 is only needed to “Stretch” the range of the 15m input to allow for 12m WARC operation (The 15m input coil would have to be readjusted to allow 15m / 12m band operation after this mod)
Not caring about 12m as it is usually dead anyway
I only installed the 10m C7 capacitor and the amp tunes and loads just fine across the entire 10m band.
I believed that Drake listed these additions / removals as “Export Models Only” covering more than just one band as WARC wasn’t available for use in the US until 1980.
It’s a lot less painful not to have to burrow into the tight pi network enclosure just to solder in a capacitor that most likely wouldn’t be utilized anyway.

Tom W9TAB


 

I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

开云体育

Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

They also used a filter to prevent 11 meter operation in some of the amps. I don't know if they were the earlier L7's or the later ones?

Merry Christmas to all and happy holidays.

Tim

WB8UHZ

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

Roger,

I worked on several L7s and don't remember access to that "stud and nut 10M lockout" being a problem in terms of access. ?As I recall, it was not in the area of the input tuning coils but further back. ?We're testing my ?15+ year memory here. ?I'll give this some more thought.

Merry Christmas,

Evan, K9SQG

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

开云体育

I just recently did the 10m mod on my L7

Tom W9TAB?

On Dec 24, 2024, at 9:08?AM, Evan via groups.io <k9sqg@...> wrote:

?
Roger,

I worked on several L7s and don't remember access to that "stud and nut 10M lockout" being a problem in terms of access. ?As I recall, it was not in the area of the input tuning coils but further back. ?We're testing my ?15+ year memory here. ?I'll give this some more thought.

Merry Christmas,

Evan, K9SQG

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

开云体育

Yes it had the band pass filter. I removed it. Now to "unlock" the band selector and add a capacitor.?
Thanks
Roger



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "amfone via groups.io" <amfone20000@...>
Date: 12/24/24 10:02 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

They also used a filter to prevent 11 meter operation in some of the amps. I don't know if they were the earlier L7's or the later ones?

Merry Christmas to all and happy holidays.

Tim

WB8UHZ

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

开云体育

Do you remember how you removed the stop in the band selector??



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Thomas W9TAB via groups.io" <electron@...>
Date: 12/24/24 11:19 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

I just recently did the 10m mod on my L7

Tom W9TAB?

On Dec 24, 2024, at 9:08?AM, Evan via groups.io <k9sqg@...> wrote:

?
Roger,

I worked on several L7s and don't remember access to that "stud and nut 10M lockout" being a problem in terms of access. ?As I recall, it was not in the area of the input tuning coils but further back. ?We're testing my ?15+ year memory here. ?I'll give this some more thought.

Merry Christmas,

Evan, K9SQG

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

You might want to give this a read.

/g/DRAKE-RADIO/files/Drake%20L7%2010%20Meter%20High%20Input%20SWR%20complete.pdf

On Wed, 25 Dec 2024 07:38:21 -0500
"Roger KW4EMF via groups.io" <rogerlhill@...> wrote:

Yes it had the band pass filter. I removed it. Now to "unlock" the band selector and add a capacitor.
--

73

-Jim
NU0C


 

开云体育

Thanks Jim. I was wondering if someone out there had made there own input tuning coil for 10m instead of just adding a capacitor.?



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Jim Shorney via groups.io" <jimNU0C@...>
Date: 12/25/24 7:53 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification


You might want to give this a read.

/g/DRAKE-RADIO/files/Drake%20L7%2010%20Meter%20High%20Input%20SWR%20complete.pdf

On Wed, 25 Dec 2024 07:38:21 -0500
"Roger KW4EMF via groups.io" <rogerlhill@...> wrote:

> Yes it had the band pass filter. I removed it. Now to "unlock" the band selector and add a capacitor.

--

73

-Jim
NU0C






 

开云体育

I just added a capacitor to mine, that’s all it took.
My SWR is 1.1 to 1.3 across entire 10m band with solid 1kw out and 60w exciter.?
Note: I did not add a capacitor to the 15m pi network as it wasn’t part of the 10m mod.?

On Dec 26, 2024, at 8:03?AM, Roger KW4EMF <rogerlhill@...> wrote:

?
Thanks Jim. I was wondering if someone out there had made there own input tuning coil for 10m instead of just adding a capacitor.?



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Jim Shorney via groups.io" <jimNU0C@...>
Date: 12/25/24 7:53 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification


You might want to give this a read.

/g/DRAKE-RADIO/files/Drake%20L7%2010%20Meter%20High%20Input%20SWR%20complete.pdf

On Wed, 25 Dec 2024 07:38:21 -0500
"Roger KW4EMF via groups.io" <rogerlhill@...> wrote:

> Yes it had the band pass filter. I removed it. Now to "unlock" the band selector and add a capacitor.

--

73

-Jim
NU0C






 

It's been a few years but IIRC I used a dental pick to coax the nut off and then popped the screw out.


On Thu, 26 Dec 2024 15:20:11 -0500
"Roger KW4EMF via groups.io" <rogerlhill@...> wrote:

It doesn't say how to get that little stop screw out of the band switch. I can see it. But don't see any way to access it short of removing the band switch.?

--

73

-Jim
NU0C


 

On one L7 that I serviced it had a "shorting" trace on the 11M filter?

On Wednesday, December 25, 2024 at 07:38:24 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Yes it had the band pass filter. I removed it. Now to "unlock" the band selector and add a capacitor.?
Thanks
Roger



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "amfone via groups.io" <amfone20000@...>
Date: 12/24/24 10:02 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

They also used a filter to prevent 11 meter operation in some of the amps. I don't know if they were the earlier L7's or the later ones?

Merry Christmas to all and happy holidays.

Tim

WB8UHZ

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

开云体育

My L7 had a shorting trace as well but I chose to remove the filter because that was where I mounted the step start, soft key and bias board at.?

On Dec 27, 2024, at 10:49?AM, Evan via groups.io <k9sqg@...> wrote:

?
On one L7 that I serviced it had a "shorting" trace on the 11M filter?

On Wednesday, December 25, 2024 at 07:38:24 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Yes it had the band pass filter. I removed it. Now to "unlock" the band selector and add a capacitor.?
Thanks
Roger



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "amfone via groups.io" <amfone20000@...>
Date: 12/24/24 10:02 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

They also used a filter to prevent 11 meter operation in some of the amps. I don't know if they were the earlier L7's or the later ones?

Merry Christmas to all and happy holidays.

Tim

WB8UHZ

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

开云体育

Do you remember where the shorting trace is? I have not heard of that before. I did get that little bolt/ nut out of the band switch and bypassed the filter board. There is no way to get conventional tools on that band switch stop like a wrench or pliers. It's between a rock and another rock in this case. I used a precision screw driver and a small hammer to peck the nut loose. Then just keep flicking it with the screw driver until it is completely unscrewed. Then fish or dump the pieces out of the amp. The first photo is the knuriled head of the screw. Second photo is the nut on the other side. Third is the narrow gap you have to go through to get at it.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Thomas W9TAB via groups.io" <electron@...>
Date: 12/27/24 11:58 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

My L7 had a shorting trace as well but I chose to remove the filter because that was where I mounted the step start, soft key and bias board at.?

On Dec 27, 2024, at 10:49?AM, Evan via groups.io <k9sqg@...> wrote:

?
On one L7 that I serviced it had a "shorting" trace on the 11M filter?

On Wednesday, December 25, 2024 at 07:38:24 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Yes it had the band pass filter. I removed it. Now to "unlock" the band selector and add a capacitor.?
Thanks
Roger



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "amfone via groups.io" <amfone20000@...>
Date: 12/24/24 10:02 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

They also used a filter to prevent 11 meter operation in some of the amps. I don't know if they were the earlier L7's or the later ones?

Merry Christmas to all and happy holidays.

Tim

WB8UHZ

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

开云体育

Yep I can see that. I used a small precision screw driver and a tiny ball peen hammer to coax the nut loose then kept flicking the nut till it fell apart.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Jim Shorney via groups.io" <jimNU0C@...>
Date: 12/26/24 5:02 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification


It's been a few years but IIRC I used a dental pick to coax the nut off and then popped the screw out.


On Thu, 26 Dec 2024 15:20:11 -0500
"Roger KW4EMF via groups.io" <rogerlhill@...> wrote:

> It doesn't say how to get that little stop screw out of the band switch. I can see it. But don't see any way to access it short of removing the band switch.?


--

73

-Jim
NU0C






 

开云体育

I think I understand. The filter board itself had a way to bypass it. I kinda made my own shorting trace.?



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/27/24 11:49 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

On one L7 that I serviced it had a "shorting" trace on the 11M filter?

On Wednesday, December 25, 2024 at 07:38:24 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Yes it had the band pass filter. I removed it. Now to "unlock" the band selector and add a capacitor.?
Thanks
Roger



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "amfone via groups.io" <amfone20000@...>
Date: 12/24/24 10:02 AM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

They also used a filter to prevent 11 meter operation in some of the amps. I don't know if they were the earlier L7's or the later ones?

Merry Christmas to all and happy holidays.

Tim

WB8UHZ

On Tuesday, December 24, 2024 at 08:39:41 AM EST, Roger KW4EMF <rogerlhill@...> wrote:


Ok. Thanks. That is a tiny crack to go through to get it. I tried to run my snake camera down in there to get a look but can't get it in there. I just removed the one small plate over the input tuning coils.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?


 

The shorting trace would be obvious if you have the later circuit board. A single wide trace running from front to back with a hole for a wire at each end. The idea was to unsolder the coax center conductor at each end and move them to the shorting trace.

On Fri, 27 Dec 2024 14:08:36 -0500
"Roger KW4EMF via groups.io" <rogerlhill@...> wrote:

Do you remember where the shorting trace is?

--

73

-Jim
NU0C


 

开云体育

Here it is. A screw with a plan head no slot or anything. Just some knurl around the outside and a nut.



Sent from my T-Mobile 5G Device


-------- Original message --------
From: "Evan via groups.io" <k9sqg@...>
Date: 12/23/24 10:59 PM (GMT-05:00)
Subject: Re: [DRAKE-RADIO] Drake L7 10m modification

Roger,

To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.

But let's hear what the experts say.

Best of luck.

73,

Evan, K9SQG

On Monday, December 23, 2024 at 10:34:43 PM EST, Roger KW4EMF <rogerlhill@...> wrote:


I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?