[ARC5] ARC5 Digest, Vol 119, Issue 29
Paddy Ryan
pei7cn at eircom.net
Mon Dec 23 08:09:13 EST 2013
dropping the B+ from 300 to 200
I use 10w 100volt zeners in series off the B+ with 10W WW dropping resistor
to power tube receivers..it is stable and regulated and very inexpensive
compared to 0A2s VR150s etc
73 de Pat/EI7CN
-----Original Message-----
From: arc5-request at mailman.qth.net
Sent: Monday, December 23, 2013 12:42 PM
To: arc5 at mailman.qth.net
Subject: ARC5 Digest, Vol 119, Issue 29
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Today's Topics:
1. Anybody Restoring an Airplane? (Robert Eleazer)
2. Re: Power Supply Filter Question (Fuqua, Bill L)
3. Re: Power Supply Filter Question (Fuqua, Bill L)
4. Re: Power Supply Filter Question (Fuqua, Bill L)
5. DC-DC: Need a Receiver Bias Supply? (David Stinson)
6. Re: DC-DC: Need a Receiver Bias Supply? (Bill Cromwell)
----------------------------------------------------------------------
Message: 1
Date: Sun, 22 Dec 2013 19:00:38 -0500
From: "Robert Eleazer" <releazer at earthlink.net>
To: <arc5 at mailman.qth.net>
Subject: [ARC5] Anybody Restoring an Airplane?
Message-ID: <002e01ceff72$035d3dc0$8550c58e at DH26DQ31>
Content-Type: text/plain; charset="iso-8859-1"
AN-74 Antennas, genuine NOS. See ebay Item 291026640133
Wayne
------------------------------
Message: 2
Date: Mon, 23 Dec 2013 03:26:51 +0000
From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
To: "jfor at quikus.com" <jfor at quikus.com>
Cc: "arc5 at mailman.qth.net" <arc5 at mailman.qth.net>, Robert Eleazer
<releazer at earthlink.net>
Subject: Re: [ARC5] Power Supply Filter Question
Message-ID:
<B7E8B5B4A202074084E2515A7B10A7F32D6871F6 at ex10mb02.ad.uky.edu>
Content-Type: text/plain; charset="us-ascii"
No, the cathode is good for at at least 300vDC
________________________________________
From: J. Forster [jfor at quikus.com]
Sent: Sunday, December 22, 2013 2:40 PM
To: Fuqua, Bill L
Cc: Robert Eleazer; arc5 at mailman.qth.net
Subject: Re: [ARC5] Power Supply Filter Question
Yes, but it takes a floatingg heater supply for the pass tube.
-John
==============
> Well,
> If you can do it with a power MOSFET you can do it with a 6080.
> It will allow as little as about 15 volts drop between plate and cathode
> with both sections in parallel and at 70ma current.
> And you still have a tube power supply.
> 73
> Bill wa4lav
>
> ________________________________________
> From: arc5-bounces at mailman.qth.net [arc5-bounces at mailman.qth.net] on
> behalf of Robert Eleazer [releazer at earthlink.net]
> Sent: Friday, December 20, 2013 9:04 PM
> To: arc5 at mailman.qth.net
> Subject: [ARC5] Power Supply Filter Question
>
> Back when I first started learning about boatanchors I read the usual ARRL
> material that described the classic way to build a power supply: a
> capacitor, an choke inductor, and a capacitor. I soon found out how rare
> and expensive the required inductors were.
>
> I was amused last year when I rebuilt the AC power supply on a BC-348-N.
> It was classic - literally right out of the Surplus Conversion Manual -
> using two fairly low valued high voltage caps and a pretty big inductor.
> I used some new, bigger, caps when I rebuilt it but left the inductor in
> place. Of course, it was also running the B+ way too high and I added
> some power resistors in both the AC input line and the B+ line. Got the
> B+ from over 250VDC down to about 200 VDC.
>
> Now, we have available high voltage caps that have much larger values that
> those 20 mfd cans we used to use and are a lot smaller as well. But I
> wonder if adding some inductance to the power supply circuit would do some
> good? Would winding some wire around a piece of steel or even around a
> nail provide better filtering than just some big caps?
>
> Thanks,
>
> Wayne
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
------------------------------
Message: 3
Date: Mon, 23 Dec 2013 03:33:02 +0000
From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
To: "jfor at quikus.com" <jfor at quikus.com>
Cc: "arc5 at mailman.qth.net" <arc5 at mailman.qth.net>, Robert Eleazer
<releazer at earthlink.net>
Subject: Re: [ARC5] Power Supply Filter Question
Message-ID:
<B7E8B5B4A202074084E2515A7B10A7F32D68720E at ex10mb02.ad.uky.edu>
Content-Type: text/plain; charset="us-ascii"
I should say the filament to cathode is good for 300 volts DC and he is
wanting around 200VDC.
Use the tube as a cathode follower and voltage divider on grid to set the
output. You can even add
a capacitor between grid and ground for additional active filtering.
73
Bill wa4lav
________________________________________
From: arc5-bounces at mailman.qth.net [arc5-bounces at mailman.qth.net] on behalf
of Fuqua, Bill L [wlfuqu00 at uky.edu]
Sent: Sunday, December 22, 2013 10:26 PM
To: jfor at quikus.com
Cc: arc5 at mailman.qth.net; Robert Eleazer
Subject: Re: [ARC5] Power Supply Filter Question
No, the cathode is good for at at least 300vDC
________________________________________
From: J. Forster [jfor at quikus.com]
Sent: Sunday, December 22, 2013 2:40 PM
To: Fuqua, Bill L
Cc: Robert Eleazer; arc5 at mailman.qth.net
Subject: Re: [ARC5] Power Supply Filter Question
Yes, but it takes a floatingg heater supply for the pass tube.
-John
==============
> Well,
> If you can do it with a power MOSFET you can do it with a 6080.
> It will allow as little as about 15 volts drop between plate and cathode
> with both sections in parallel and at 70ma current.
> And you still have a tube power supply.
> 73
> Bill wa4lav
>
> ________________________________________
> From: arc5-bounces at mailman.qth.net [arc5-bounces at mailman.qth.net] on
> behalf of Robert Eleazer [releazer at earthlink.net]
> Sent: Friday, December 20, 2013 9:04 PM
> To: arc5 at mailman.qth.net
> Subject: [ARC5] Power Supply Filter Question
>
> Back when I first started learning about boatanchors I read the usual ARRL
> material that described the classic way to build a power supply: a
> capacitor, an choke inductor, and a capacitor. I soon found out how rare
> and expensive the required inductors were.
>
> I was amused last year when I rebuilt the AC power supply on a BC-348-N.
> It was classic - literally right out of the Surplus Conversion Manual -
> using two fairly low valued high voltage caps and a pretty big inductor.
> I used some new, bigger, caps when I rebuilt it but left the inductor in
> place. Of course, it was also running the B+ way too high and I added
> some power resistors in both the AC input line and the B+ line. Got the
> B+ from over 250VDC down to about 200 VDC.
>
> Now, we have available high voltage caps that have much larger values that
> those 20 mfd cans we used to use and are a lot smaller as well. But I
> wonder if adding some inductance to the power supply circuit would do some
> good? Would winding some wire around a piece of steel or even around a
> nail provide better filtering than just some big caps?
>
> Thanks,
>
> Wayne
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net
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------------------------------
Message: 4
Date: Mon, 23 Dec 2013 03:34:21 +0000
From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
To: "jfor at quikus.com" <jfor at quikus.com>
Cc: "arc5 at mailman.qth.net" <arc5 at mailman.qth.net>, Robert Eleazer
<releazer at earthlink.net>
Subject: Re: [ARC5] Power Supply Filter Question
Message-ID:
<B7E8B5B4A202074084E2515A7B10A7F32D687222 at ex10mb02.ad.uky.edu>
Content-Type: text/plain; charset="us-ascii"
naturally a 6AS7 will work as well.
________________________________________
From: arc5-bounces at mailman.qth.net [arc5-bounces at mailman.qth.net] on behalf
of Fuqua, Bill L [wlfuqu00 at uky.edu]
Sent: Sunday, December 22, 2013 10:33 PM
To: jfor at quikus.com
Cc: arc5 at mailman.qth.net; Robert Eleazer
Subject: Re: [ARC5] Power Supply Filter Question
I should say the filament to cathode is good for 300 volts DC and he is
wanting around 200VDC.
Use the tube as a cathode follower and voltage divider on grid to set the
output. You can even add
a capacitor between grid and ground for additional active filtering.
73
Bill wa4lav
________________________________________
From: arc5-bounces at mailman.qth.net [arc5-bounces at mailman.qth.net] on behalf
of Fuqua, Bill L [wlfuqu00 at uky.edu]
Sent: Sunday, December 22, 2013 10:26 PM
To: jfor at quikus.com
Cc: arc5 at mailman.qth.net; Robert Eleazer
Subject: Re: [ARC5] Power Supply Filter Question
No, the cathode is good for at at least 300vDC
________________________________________
From: J. Forster [jfor at quikus.com]
Sent: Sunday, December 22, 2013 2:40 PM
To: Fuqua, Bill L
Cc: Robert Eleazer; arc5 at mailman.qth.net
Subject: Re: [ARC5] Power Supply Filter Question
Yes, but it takes a floatingg heater supply for the pass tube.
-John
==============
> Well,
> If you can do it with a power MOSFET you can do it with a 6080.
> It will allow as little as about 15 volts drop between plate and cathode
> with both sections in parallel and at 70ma current.
> And you still have a tube power supply.
> 73
> Bill wa4lav
>
> ________________________________________
> From: arc5-bounces at mailman.qth.net [arc5-bounces at mailman.qth.net] on
> behalf of Robert Eleazer [releazer at earthlink.net]
> Sent: Friday, December 20, 2013 9:04 PM
> To: arc5 at mailman.qth.net
> Subject: [ARC5] Power Supply Filter Question
>
> Back when I first started learning about boatanchors I read the usual ARRL
> material that described the classic way to build a power supply: a
> capacitor, an choke inductor, and a capacitor. I soon found out how rare
> and expensive the required inductors were.
>
> I was amused last year when I rebuilt the AC power supply on a BC-348-N.
> It was classic - literally right out of the Surplus Conversion Manual -
> using two fairly low valued high voltage caps and a pretty big inductor.
> I used some new, bigger, caps when I rebuilt it but left the inductor in
> place. Of course, it was also running the B+ way too high and I added
> some power resistors in both the AC input line and the B+ line. Got the
> B+ from over 250VDC down to about 200 VDC.
>
> Now, we have available high voltage caps that have much larger values that
> those 20 mfd cans we used to use and are a lot smaller as well. But I
> wonder if adding some inductance to the power supply circuit would do some
> good? Would winding some wire around a piece of steel or even around a
> nail provide better filtering than just some big caps?
>
> Thanks,
>
> Wayne
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
------------------------------
Message: 5
Date: Mon, 23 Dec 2013 05:56:13 -0600
From: "David Stinson" <arc5 at ix.netcom.com>
To: "ARC-5 List" <arc5 at mailman.qth.net>
Subject: [ARC5] DC-DC: Need a Receiver Bias Supply?
Message-ID: <27A5D4F80CE74621B9F2E9EE3D2A630F at CompaqSR5710F>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Another use for these little DC-DC converter bricks:
If you get one that's isolated (the output does not share a common
negative or ground with the input), you can use it to "flip"
your A+ voltage of 6, 12, or 24 volts and zener it to a nice
little bias supply.
There are many little low-current converters available for cheap
with various inputs and outputs.
For example- if your A+ is 12 Volts and you need -7.5 bias,
get one that does 10-16 Volts in, 9 or 12 Volts out.
Resistor and a zener and away you go.
The RFI situation may vary, but I've built a couple of supplies
using DC-DC converters with ferrites and a metal box to
encase them. It's worked for me with the residual "birdies" not
being any problem (hey... whadda ya want for a $10 supply??).
To see what's available, search the Bay with this string:
-non dc-dc converter isolated
"-non" because otherwise it will list "non-isolated" and that
won't work for a bias supply.
73 DE Dave AB5S
------------------------------
Message: 6
Date: Mon, 23 Dec 2013 07:42:02 -0500
From: Bill Cromwell <wrcromwell at gmail.com>
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] DC-DC: Need a Receiver Bias Supply?
Message-ID: <52B82F9A.7010104 at gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 12/23/2013 06:56 AM, David Stinson wrote:
> Another use for these little DC-DC converter bricks:
> If you get one that's isolated (the output does not share a common
> negative or ground with the input), you can use it to "flip"
> your A+ voltage of 6, 12, or 24 volts and zener it to a nice little
> bias supply.
> There are many little low-current converters available for cheap with
> various inputs and outputs.
> For example- if your A+ is 12 Volts and you need -7.5 bias,
> get one that does 10-16 Volts in, 9 or 12 Volts out. Resistor and a
> zener and away you go.
>
> The RFI situation may vary, but I've built a couple of supplies using
> DC-DC converters with ferrites and a metal box to encase them. It's
> worked for me with the residual "birdies" not
> being any problem (hey... whadda ya want for a $10 supply??).
>
> To see what's available, search the Bay with this string:
>
> -non dc-dc converter isolated
>
> "-non" because otherwise it will list "non-isolated" and that
> won't work for a bias supply.
>
> 73 DE Dave AB5S
Hi Dave,
I haven't used zener diodes in a grid circuit as they are reported to be
excellent noise generators. I'm reluctant to put a noise generator on a
grid and degrade the receiver's noise performance. Since I haven't used
a zener diode in a grid circuit I can't attest to a noise problem. I AM
building a noise-impedance bridge and I have confidence the zener diode
in that will do it's job.
Are there some people who have used a zener diode in a grid circuit
(bias supply regulator) without noise problems? Maybe with a filter cap?
73,
Bill KU8H
------------------------------
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