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K4DPK VFO Stabilizer


 

¿ªÔÆÌåÓý

I¡¯ll soon be installing a K4DPK VFO stabilizer in my TR-4Cw.? The stabilizer works on 10-14 VDC.? Since there¡¯s no low voltage in the TR-4Cw, I¡¯m curious how others have attempted the supply voltage dilemma,.? Here are some options:

?

  1. Use the 12.6VAC filament line and use a well filtered half-wave rectifier and Zener diode.? The stabilizer draws relatively low current so ripple shouldn¡¯t be too difficult to manage;
  2. Use a filtered full-wave bridge rectifier on the 12.6VAC line for better ripple suppression. ?Note that one side of the 12.6VAC winding from the AC-4 power supply is grounded/bonded to the chassis.? As such, a standard two-diode full wave rectifier isn¡¯t easily managed here;
  3. Or as Drake engineers loved, consider hot, power-hungry wire wound resistors to drop voltage on one of the B+ lines.? Frankly, it¡¯s not an option to add even more cabinet heat to a problem that is heat generated in the first place;
  4. External DC wall cube.? This throw-in-the-towel solution and #3 above just aren¡¯t viable for me.? ?

?

Other options come to mind?? I¡¯m not keen on anything that uses DC-DC switching regulators no matter how well they¡¯re filtered.?

?

Paul, W9AC


 

On 2024-01-18 11:17, Paul Christensen wrote:
I'll soon be installing a K4DPK VFO stabilizer in my TR-4Cw. The
stabilizer works on 10-14 VDC. Since there's no low voltage in the
TR-4Cw, I'm curious how others have attempted the supply voltage
dilemma,
*** I had a similar requirement for my KWM-2. I used a half-wave rectifier
off the filament circuit, feeding a TO-92 three-terminal regulator. Which
has far better ripple rejection than a zener diode.

Actually, I wound up using two half-wave rectifier circuits; one for
a BHI noise reduction module inserted in the audio stream, and the other
for a DC fan.

In the case of the KWM2, there was an empty tube socket on the chassis,
meant for a noise blanker option. This had most of the signals I needed,
including a switch closure for the "NB" position on the front panel. So
now when I click to "NB", the band noise goes down. I mostly leave it in
"NB".

- Jerry, KF6VB


 

Jerry,

You probably used a 78L12?

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of jerry-KF6VB
Sent: Thursday, January 18, 2024 2:52 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] K4DPK VFO Stabilizer

On 2024-01-18 11:17, Paul Christensen wrote:
I'll soon be installing a K4DPK VFO stabilizer in my TR-4Cw. The
stabilizer works on 10-14 VDC. Since there's no low voltage in the
TR-4Cw, I'm curious how others have attempted the supply voltage
dilemma,
*** I had a similar requirement for my KWM-2. I used a half-wave rectifier
off the filament circuit, feeding a TO-92 three-terminal regulator.
Which
has far better ripple rejection than a zener diode.

Actually, I wound up using two half-wave rectifier circuits; one for a BHI
noise reduction module inserted in the audio stream, and the other for a DC
fan.

In the case of the KWM2, there was an empty tube socket on the chassis,
meant for a noise blanker option. This had most of the signals I needed,
including a switch closure for the "NB" position on the front panel. So now
when I click to "NB", the band noise goes down. I mostly leave it in "NB".

- Jerry, KF6VB


 

Even better, use a 317T regulator *with recommended external caps*. Better specs and you can set the voltage to exactly what you want.

73

-Jim
NU0C

On Thu, 18 Jan 2024 11:52:15 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-01-18 11:17, Paul Christensen wrote:
I'll soon be installing a K4DPK VFO stabilizer in my TR-4Cw. The
stabilizer works on 10-14 VDC. Since there's no low voltage in the
TR-4Cw, I'm curious how others have attempted the supply voltage
dilemma,
*** I had a similar requirement for my KWM-2. I used a half-wave
rectifier
off the filament circuit, feeding a TO-92 three-terminal regulator.
Which
has far better ripple rejection than a zener diode.

Actually, I wound up using two half-wave rectifier circuits; one for
a BHI noise reduction module inserted in the audio stream, and the other
for a DC fan.

In the case of the KWM2, there was an empty tube socket on the
chassis,
meant for a noise blanker option. This had most of the signals I
needed,
including a switch closure for the "NB" position on the front panel. So
now when I click to "NB", the band noise goes down. I mostly leave it
in
"NB".

- Jerry, KF6VB






--

73

-Jim
NU0C


 

On 2024-01-18 12:06, Paul Christensen wrote:
Jerry,
You probably used a 78L12?
*** That sounds about right. And now that I remember, I used
a 1/2 wave voltage doubler running off the 6.3VAC.

- Jerry, KF6VB


 

Jim,

I don't believe the 317T is a low-drop-out regulator. There won't be much
In-Out margin on the 12.6 VAC string during a brown-out condition with
half-wave rectification. It also requires (or strongly suggested by the
OEMs) use of protection diodes across the I/O terminals and output.
Considering the low current draw and wide supply range of the K4DPK
stabilizer, 78L10 or 78L12 should be sufficient.

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Thursday, January 18, 2024 3:10 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] K4DPK VFO Stabilizer


Even better, use a 317T regulator *with recommended external caps*. Better
specs and you can set the voltage to exactly what you want.

73

-Jim
NU0C

On Thu, 18 Jan 2024 11:52:15 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-01-18 11:17, Paul Christensen wrote:
I'll soon be installing a K4DPK VFO stabilizer in my TR-4Cw. The
stabilizer works on 10-14 VDC. Since there's no low voltage in the
TR-4Cw, I'm curious how others have attempted the supply voltage
dilemma,
*** I had a similar requirement for my KWM-2. I used a half-wave
rectifier off the filament circuit, feeding a TO-92 three-terminal
regulator.
Which
has far better ripple rejection than a zener diode.

Actually, I wound up using two half-wave rectifier circuits; one for
a BHI noise reduction module inserted in the audio stream, and the
other for a DC fan.

In the case of the KWM2, there was an empty tube socket on the
chassis, meant for a noise blanker option. This had most of the
signals I needed, including a switch closure for the "NB" position on
the front panel. So now when I click to "NB", the band noise goes
down. I mostly leave it in "NB".

- Jerry, KF6VB






--

73

-Jim
NU0C


 

Paul

I have not read the other suggestions, but two come to mind

1. Can you unground one side of the AC for heaters.? Normally it is a twisted pair.? I used a bridge to pull down the heater voltage on a R4C from 7.0 to 6.5. (It had forfeited some tubes for transistors)

2. There are very cheap DC to DC converters (sometimes called regulators or step up or step down (buck) but are adjustable for output voltage) from China on the internet, for $5.? So rectify your heater voltage - half wave may be OK.? The two sides of the converter are electrically isolated.

I used one also on a drake R2C using a replacement mains transformer that did not have a 12.6V output.? So boosted from 6.3V.? If there is interference put the ferrite beads on the wires.

Nigel




On Thu, Jan 18, 2024 at 8:09?PM Jim Shorney <jimNU0C@...> wrote:

Even better, use a 317T regulator *with recommended external caps*. Better specs and you can set the voltage to exactly what you want.

73

-Jim
NU0C

On Thu, 18 Jan 2024 11:52:15 -0800
"jerry-KF6VB" <jerry@...> wrote:

> On 2024-01-18 11:17, Paul Christensen wrote:
> > I'll soon be installing a K4DPK VFO stabilizer in my TR-4Cw.? The
> > stabilizer works on 10-14 VDC.? Since there's no low voltage in the
> > TR-4Cw, I'm curious how others have attempted the supply voltage
> > dilemma,?
>
> *** I had a similar requirement for my KWM-2.? I used a half-wave
> rectifier
> off the filament circuit, feeding a TO-92 three-terminal regulator.?
> Which
> has far better ripple rejection than a zener diode.
>
> Actually, I wound up using two half-wave rectifier circuits;? one for
> a BHI noise reduction module inserted in the audio stream, and the other
> for a DC fan.
>
>? ? In the case of the KWM2, there was an empty tube socket on the
> chassis,
> meant for a noise blanker option.? This had most of the signals I
> needed,
> including a switch closure for the "NB" position on the front panel.? So
> now when I click to "NB", the band noise goes down.? I mostly leave it
> in
> "NB".
>
>? ? ? ? ? ? ? ? ? ?- Jerry, KF6VB
>
>
>
>
>



--

73

-Jim
NU0C






 

¿ªÔÆÌåÓý

Nigel,

?

I would like to avoid switching/bucking DC-DC regulators.? Sometimes they seem fine only to discover a spur or two some time after a mod is made.

?

Just me, but I think all vacuum tube gear should run without grounded heater returns.? In audio stages, it¡¯s so much easier to balance out hum that way.?

?

Yes, it¡¯s possible to un-ground the heaters but have a look at the collision of parts and wiring under a TR-4Cw.? Adding a dedicated wiring string for the heater return on all tubes would be a nightmare.?

?

Paul, W9AC

?

From: [email protected] <[email protected]> On Behalf Of nigel patterson G3YDT
Sent: Thursday, January 18, 2024 3:31 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] K4DPK VFO Stabilizer

?

Paul

?

I have not read the other suggestions, but two come to mind

?

1. Can you unground one side of the AC for heaters.? Normally it is a twisted pair.? I used a bridge to pull down the heater voltage on a R4C from 7.0 to 6.5. (It had forfeited some tubes for transistors)

?

2. There are very cheap DC to DC converters (sometimes called regulators or step up or step down (buck) but are adjustable for output voltage) from China on the internet, for $5.? So rectify your heater voltage - half wave may be OK.? The two sides of the converter are electrically isolated.

?

I used one also on a drake R2C using a replacement mains transformer that did not have a 12.6V output.? So boosted from 6.3V.? If there is interference put the ferrite beads on the wires.

?

Nigel

?

?

?

?

On Thu, Jan 18, 2024 at 8:09?PM Jim Shorney <jimNU0C@...> wrote:


Even better, use a 317T regulator *with recommended external caps*. Better specs and you can set the voltage to exactly what you want.

73

-Jim
NU0C

On Thu, 18 Jan 2024 11:52:15 -0800
"jerry-KF6VB" <jerry@...> wrote:

> On 2024-01-18 11:17, Paul Christensen wrote:
> > I'll soon be installing a K4DPK VFO stabilizer in my TR-4Cw.? The
> > stabilizer works on 10-14 VDC.? Since there's no low voltage in the
> > TR-4Cw, I'm curious how others have attempted the supply voltage
> > dilemma,?
>
> *** I had a similar requirement for my KWM-2.? I used a half-wave
> rectifier
> off the filament circuit, feeding a TO-92 three-terminal regulator.?
> Which
> has far better ripple rejection than a zener diode.
>
> Actually, I wound up using two half-wave rectifier circuits;? one for
> a BHI noise reduction module inserted in the audio stream, and the other
> for a DC fan.
>
>? ? In the case of the KWM2, there was an empty tube socket on the
> chassis,
> meant for a noise blanker option.? This had most of the signals I
> needed,
> including a switch closure for the "NB" position on the front panel.? So
> now when I click to "NB", the band noise goes down.? I mostly leave it
> in
> "NB".
>
>? ? ? ? ? ? ? ? ? ?- Jerry, KF6VB
>
>
>
>
>



--

73

-Jim
NU0C





 

There are LDO versions of the 317 series. Fixed regulators can also benefit from a protection diode. The risk is if the input voltage falls below the output voltage. Diodes are cheap. I have a tendency to add one if I have to replace a regulator.

73

-Jim
NU0C

On Thu, 18 Jan 2024 15:25:49 -0500
"Paul Christensen" <w9ac@...> wrote:

Jim,

I don't believe the 317T is a low-drop-out regulator. There won't be much
In-Out margin on the 12.6 VAC string during a brown-out condition with
half-wave rectification. It also requires (or strongly suggested by the
OEMs) use of protection diodes across the I/O terminals and output.
Considering the low current draw and wide supply range of the K4DPK
stabilizer, 78L10 or 78L12 should be sufficient.

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Thursday, January 18, 2024 3:10 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] K4DPK VFO Stabilizer


Even better, use a 317T regulator *with recommended external caps*. Better
specs and you can set the voltage to exactly what you want.

73

-Jim
NU0C

On Thu, 18 Jan 2024 11:52:15 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-01-18 11:17, Paul Christensen wrote:
I'll soon be installing a K4DPK VFO stabilizer in my TR-4Cw. The
stabilizer works on 10-14 VDC. Since there's no low voltage in the
TR-4Cw, I'm curious how others have attempted the supply voltage
dilemma,
*** I had a similar requirement for my KWM-2. I used a half-wave
rectifier off the filament circuit, feeding a TO-92 three-terminal
regulator.
Which
has far better ripple rejection than a zener diode.

Actually, I wound up using two half-wave rectifier circuits; one for
a BHI noise reduction module inserted in the audio stream, and the
other for a DC fan.

In the case of the KWM2, there was an empty tube socket on the
chassis, meant for a noise blanker option. This had most of the
signals I needed, including a switch closure for the "NB" position on
the front panel. So now when I click to "NB", the band noise goes
down. I mostly leave it in "NB".

- Jerry, KF6VB







--

73

-Jim
NU0C


 

Also marketed as LED drivers. I have an adjustable one driving the +20v PLL power source in a Uniden scanner as the original dead chip was unobtanium at the time. It's been working well for a couple of years now.

73

-Jim
NU0C

On Thu, 18 Jan 2024 20:31:19 +0000
"nigel patterson G3YDT" <wnigelpatterson@...> wrote:

There are very cheap DC to DC converters (sometimes called regulators or
step up or step down (buck) but are adjustable for output voltage) from
China on the internet, for $5.

--

73

-Jim
NU0C


 

Paul, what's the current requirement for that VFO stabilizer board?

73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com

On 1/18/2024 4:28 PM, Jim Shorney wrote:
There are LDO versions of the 317 series. Fixed regulators can also benefit from a protection diode. The risk is if the input voltage falls below the output voltage. Diodes are cheap. I have a tendency to add one if I have to replace a regulator.

73

-Jim
NU0C

On Thu, 18 Jan 2024 15:25:49 -0500
"Paul Christensen" <w9ac@...> wrote:

Jim,

I don't believe the 317T is a low-drop-out regulator. There won't be much
In-Out margin on the 12.6 VAC string during a brown-out condition with
half-wave rectification. It also requires (or strongly suggested by the
OEMs) use of protection diodes across the I/O terminals and output.
Considering the low current draw and wide supply range of the K4DPK
stabilizer, 78L10 or 78L12 should be sufficient.

Paul, W9AC

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim Shorney
Sent: Thursday, January 18, 2024 3:10 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] K4DPK VFO Stabilizer


Even better, use a 317T regulator *with recommended external caps*. Better
specs and you can set the voltage to exactly what you want.

73

-Jim
NU0C

On Thu, 18 Jan 2024 11:52:15 -0800
"jerry-KF6VB" <jerry@...> wrote:

On 2024-01-18 11:17, Paul Christensen wrote:
I'll soon be installing a K4DPK VFO stabilizer in my TR-4Cw. The
stabilizer works on 10-14 VDC. Since there's no low voltage in the
TR-4Cw, I'm curious how others have attempted the supply voltage
dilemma,
*** I had a similar requirement for my KWM-2. I used a half-wave
rectifier off the filament circuit, feeding a TO-92 three-terminal
regulator.
Which
has far better ripple rejection than a zener diode.

Actually, I wound up using two half-wave rectifier circuits; one for
a BHI noise reduction module inserted in the audio stream, and the
other for a DC fan.

In the case of the KWM2, there was an empty tube socket on the
chassis, meant for a noise blanker option. This had most of the
signals I needed, including a switch closure for the "NB" position on
the front panel. So now when I click to "NB", the band noise goes
down. I mostly leave it in "NB".

- Jerry, KF6VB





 

As to DC ?wall cubes, test first. ?Some of them have high onset voltage until the regulator kicks in, and some of them are prone to RFI altering the output voltage.

On Thursday, January 18, 2024 at 02:17:48 PM EST, Paul Christensen <w9ac@...> wrote:


I¡¯ll soon be installing a K4DPK VFO stabilizer in my TR-4Cw.? The stabilizer works on 10-14 VDC.? Since there¡¯s no low voltage in the TR-4Cw, I¡¯m curious how others have attempted the supply voltage dilemma,.? Here are some options:

?

  1. Use the 12.6VAC filament line and use a well filtered half-wave rectifier and Zener diode.? The stabilizer draws relatively low current so ripple shouldn¡¯t be too difficult to manage;
  2. Use a filtered full-wave bridge rectifier on the 12.6VAC line for better ripple suppression. ?Note that one side of the 12.6VAC winding from the AC-4 power supply is grounded/bonded to the chassis.? As such, a standard two-diode full wave rectifier isn¡¯t easily managed here;
  3. Or as Drake engineers loved, consider hot, power-hungry wire wound resistors to drop voltage on one of the B+ lines.? Frankly, it¡¯s not an option to add even more cabinet heat to a problem that is heat generated in the first place;
  4. External DC wall cube.? This throw-in-the-towel solution and #3 above just aren¡¯t viable for me.? ?

?

Other options come to mind?? I¡¯m not keen on anything that uses DC-DC switching regulators no matter how well they¡¯re filtered.?

?

Paul, W9AC


 

>"Paul, what's the current requirement for that VFO stabilizer board? 73/jeff/ac0c"

Jeff,

No spec but the stabilizer has four CMOS chips and one LED with the LED drawing the most current.? So, 15-20 mA.? Either a 78L10 or 1/2W 10V Zener should be fine.? The 78Lxx devices are good to a max current of 100mA.? Rather than one 'lytic filter cap, I'll use four in parallel after the half-wave rectifier.

Paul, W9AC??


 

I will no longer use any wall warts to supply DC to anything that¡¯s sensitive. I learned the hard way with one of my old Trac CMOS keyers. I had to replace all eight chips and a transistor when the wart failed.?

Steve Wedge, W1ES/4

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


Sent from for iOS


On Thu, Jan 18, 2024 at 21:45, Evan via groups.io <k9sqg@...> wrote:
As to DC ?wall cubes, test first. ?Some of them have high onset voltage until the regulator kicks in, and some of them are prone to RFI altering the output voltage.

On Thursday, January 18, 2024 at 02:17:48 PM EST, Paul Christensen <w9ac@...> wrote:


I¡¯ll soon be installing a K4DPK VFO stabilizer in my TR-4Cw.? The stabilizer works on 10-14 VDC.? Since there¡¯s no low voltage in the TR-4Cw, I¡¯m curious how others have attempted the supply voltage dilemma,.? Here are some options:

?

  1. Use the 12.6VAC filament line and use a well filtered half-wave rectifier and Zener diode.? The stabilizer draws relatively low current so ripple shouldn¡¯t be too difficult to manage;
  2. Use a filtered full-wave bridge rectifier on the 12.6VAC line for better ripple suppression. ?Note that one side of the 12.6VAC winding from the AC-4 power supply is grounded/bonded to the chassis.? As such, a standard two-diode full wave rectifier isn¡¯t easily managed here;
  3. Or as Drake engineers loved, consider hot, power-hungry wire wound resistors to drop voltage on one of the B+ lines.? Frankly, it¡¯s not an option to add even more cabinet heat to a problem that is heat generated in the first place;
  4. External DC wall cube.? This throw-in-the-towel solution and #3 above just aren¡¯t viable for me.? ?

?

Other options come to mind?? I¡¯m not keen on anything that uses DC-DC switching regulators no matter how well they¡¯re filtered.?

?

Paul, W9AC


 

¿ªÔÆÌåÓý

?Curious if your bad experience was with a switching or linear wall wart???

Dan
WB4GRA


On Jan 19, 2024, at 9:22?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:

?
I will no longer use any wall warts to supply DC to anything that¡¯s sensitive. I learned the hard way with one of my old Trac CMOS keyers. I had to replace all eight chips and a transistor when the wart failed.?

Steve Wedge, W1ES/4

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


Sent from for iOS


On Thu, Jan 18, 2024 at 21:45, Evan via groups.io <k9sqg@...> wrote:
As to DC ?wall cubes, test first. ?Some of them have high onset voltage until the regulator kicks in, and some of them are prone to RFI altering the output voltage.

On Thursday, January 18, 2024 at 02:17:48 PM EST, Paul Christensen <w9ac@...> wrote:


I¡¯ll soon be installing a K4DPK VFO stabilizer in my TR-4Cw.? The stabilizer works on 10-14 VDC.? Since there¡¯s no low voltage in the TR-4Cw, I¡¯m curious how others have attempted the supply voltage dilemma,.? Here are some options:

?

  1. Use the 12.6VAC filament line and use a well filtered half-wave rectifier and Zener diode.? The stabilizer draws relatively low current so ripple shouldn¡¯t be too difficult to manage;
  2. Use a filtered full-wave bridge rectifier on the 12.6VAC line for better ripple suppression. ?Note that one side of the 12.6VAC winding from the AC-4 power supply is grounded/bonded to the chassis.? As such, a standard two-diode full wave rectifier isn¡¯t easily managed here;
  3. Or as Drake engineers loved, consider hot, power-hungry wire wound resistors to drop voltage on one of the B+ lines.? Frankly, it¡¯s not an option to add even more cabinet heat to a problem that is heat generated in the first place;
  4. External DC wall cube.? This throw-in-the-towel solution and #3 above just aren¡¯t viable for me.? ?

?

Other options come to mind?? I¡¯m not keen on anything that uses DC-DC switching regulators no matter how well they¡¯re filtered.?

?

Paul, W9AC


 

Not sure but good point.?

I used to disconnect the 9V battery when I wasn¡¯t using it but have discovered that I¡¯ll get at least a year out of a battery even if I just leave it, so that¡¯s how I¡¯m doing it now.?

Steve Wedge, W1ES/4

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


Sent from for iOS


On Fri, Jan 19, 2024 at 09:49, Dan <pitfit@...> wrote:
?Curious if your bad experience was with a switching or linear wall wart???

Dan
WB4GRA


On Jan 19, 2024, at 9:22?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:

?
I will no longer use any wall warts to supply DC to anything that¡¯s sensitive. I learned the hard way with one of my old Trac CMOS keyers. I had to replace all eight chips and a transistor when the wart failed.?

Steve Wedge, W1ES/4

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


Sent from for iOS


On Thu, Jan 18, 2024 at 21:45, Evan via groups.io <k9sqg@...> wrote:
As to DC ?wall cubes, test first. ?Some of them have high onset voltage until the regulator kicks in, and some of them are prone to RFI altering the output voltage.

On Thursday, January 18, 2024 at 02:17:48 PM EST, Paul Christensen <w9ac@...> wrote:


I¡¯ll soon be installing a K4DPK VFO stabilizer in my TR-4Cw.? The stabilizer works on 10-14 VDC.? Since there¡¯s no low voltage in the TR-4Cw, I¡¯m curious how others have attempted the supply voltage dilemma,.? Here are some options:

?

  1. Use the 12.6VAC filament line and use a well filtered half-wave rectifier and Zener diode.? The stabilizer draws relatively low current so ripple shouldn¡¯t be too difficult to manage;
  2. Use a filtered full-wave bridge rectifier on the 12.6VAC line for better ripple suppression. ?Note that one side of the 12.6VAC winding from the AC-4 power supply is grounded/bonded to the chassis.? As such, a standard two-diode full wave rectifier isn¡¯t easily managed here;
  3. Or as Drake engineers loved, consider hot, power-hungry wire wound resistors to drop voltage on one of the B+ lines.? Frankly, it¡¯s not an option to add even more cabinet heat to a problem that is heat generated in the first place;
  4. External DC wall cube.? This throw-in-the-towel solution and #3 above just aren¡¯t viable for me.? ?

?

Other options come to mind?? I¡¯m not keen on anything that uses DC-DC switching regulators no matter how well they¡¯re filtered.?

?

Paul, W9AC


 

Modern switching wall warts are pretty good.
Think about it, they power all kinds of expensive sensitive gadgets.. ie: the $1k iPhone in your pocket!
I especially like the little 1in Apple wart.? I have had one of those powering my Arduino/Si5351 GPSDO for years now and not a problem.
There are counterfeits out there though which have a fraction of the parts inside as the Apple.
73,
Gary
WB6OGD

?


 

It used to be that iPhones wouldn't charge on just any 5V USB charger.? There is/was an extra wire that signaled the iPhone it could charge from the charger which essentially meant you had to buy Apple's more expensive charger.? I don't think that's still the case since Apple switched to the smaller charger connector.

Thanks,
Barry - N4BUQ


From: "GARY WINBLAD" <garywinblad@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Friday, January 19, 2024 9:12:34 AM
Subject: Re: [DRAKE-RADIO] K4DPK VFO Stabilizer

Modern switching wall warts are pretty good.
Think about it, they power all kinds of expensive sensitive gadgets.. ie: the $1k iPhone in your pocket!
I especially like the little 1in Apple wart.? I have had one of those powering my Arduino/Si5351 GPSDO for years now and not a problem.
There are counterfeits out there though which have a fraction of the parts inside as the Apple.
73,
Gary
WB6OGD

?



 

¿ªÔÆÌåÓý

For homebrew stuff, and things I've refurbed and worry a bit about, I have started putting in TVS diodes across the circuit input, post regulator.? This is sort of a quick & easy poor man's overvoltage protection method in that the TVS can disipate a ton of power and in the event of a failing pass transistor in a regulator can force a primary side fuse to pop.? TVS are cheap and it's easy to do other than picking the right value.

73/jeff/ac0c
alpha-charlie-zero-charlie
On 1/19/2024 11:06 AM, n4buq wrote:

It used to be that iPhones wouldn't charge on just any 5V USB charger.? There is/was an extra wire that signaled the iPhone it could charge from the charger which essentially meant you had to buy Apple's more expensive charger.? I don't think that's still the case since Apple switched to the smaller charger connector.

Thanks,
Barry - N4BUQ


From: "GARY WINBLAD" <garywinblad@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Friday, January 19, 2024 9:12:34 AM
Subject: Re: [DRAKE-RADIO] K4DPK VFO Stabilizer

Modern switching wall warts are pretty good.
Think about it, they power all kinds of expensive sensitive gadgets.. ie: the $1k iPhone in your pocket!
I especially like the little 1in Apple wart.? I have had one of those powering my Arduino/Si5351 GPSDO for years now and not a problem.
There are counterfeits out there though which have a fraction of the parts inside as the Apple.
73,
Gary
WB6OGD

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Barry,
True, but that was a long time ago.
And I am using the Apple wart to power other things.. (as well as charging my phone).
73,
Gary
WB6OGD
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On 01/19/2024 9:06 AM PST n4buq <n4buq@...> wrote:
?
?
It used to be that iPhones wouldn't charge on just any 5V USB charger.? There is/was an extra wire that signaled the iPhone it could charge from the charger which essentially meant you had to buy Apple's more expensive charger.? I don't think that's still the case since Apple switched to the smaller charger connector.
?
Thanks,
Barry - N4BUQ
?

From: "GARY WINBLAD" <garywinblad@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Friday, January 19, 2024 9:12:34 AM
Subject: Re: [DRAKE-RADIO] K4DPK VFO Stabilizer

Modern switching wall warts are pretty good.
Think about it, they power all kinds of expensive sensitive gadgets.. ie: the $1k iPhone in your pocket!
I especially like the little 1in Apple wart.? I have had one of those powering my Arduino/Si5351 GPSDO for years now and not a problem.
There are counterfeits out there though which have a fraction of the parts inside as the Apple.
73,
Gary
WB6OGD

?