Metalwork - Lathe and Mill topics: December 2023

Sunday, 31 December 2023

[Amateur-repairs] Test Gear For Sale Starting with a "HEATHKIT IP-5220 AC Adjustable Power Supply"

Selling a HEATHKIT IP-5220 AC Power Supply. With original Manual. I am selling this for the original builder and owner. He is cutting back and downsizing.
Unit works as expected. Cosmetically very good, a little more Windex may help. Except for the front panel lower left. The paint/stencil? is marred. He did not remember why. See pictures.
. Much better than just a Variac. More stuff to come
$200 pick up in South Aiken County South Carolina. It is pretty heavy with the big transformer Not sure what shipping would cost.

_._,_._,_

Groups.io Links:

You receive all messages sent to this group.

_._,_._,_

Monday, 25 December 2023

Re: [Amateur-repairs] SETTING UP A TEST BENCH

Hi All

Regardless of what equipment is provided on the bench you need a clearly
illuminated single point for switching the bench on and off including
the item under test that everyone in the house knows about in case you
get into trouble.

Out of interest I do not support the variac and lamp method of reforming
electrolytics in old gear. I prefer the longer method of using a series
resistor and separate supply - article on my technical website explains
my method but everyone to their own.

Best wishes for the new year

--
73

Bob

Bob F Burns G3OOU, G-QRP 6907, @BobFBurns
Crystal Palace Radio & Electronics Club: https://www.cprec.org/
Admin/sales site: http://www.g3oou.co.uk/
Technical site: www.qsl.net/g3oou

-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#90902): https://groups.io/g/Amateur-repairs/message/90902
Mute This Topic: https://groups.io/mt/102090237/693790
Group Owner: Amateur-repairs+owner@groups.io
Unsubscribe: https://groups.io/g/Amateur-repairs/leave/4530700/693790/458576413/xyzzy [jhjoshan@gmail.com]
-=-=-=-=-=-=-=-=-=-=-=-

Re: [Amateur-repairs] SETTING UP A TEST BENCH

I use halogen bulbs as they are readily available. My dim bulb tester a 20A Variac and has halogen bulbs inside a cabinet, a rotary switch to select from 7.5W (a panel mounted bulb across the bulbs) connected in a Binary arrangement so I can select 7.5w to 507.5W in 50W increments. The last selection of the knob connects the output directly to the load.

I also included a digital display indicating output volts, load current and wattage. There is a 100W isolation transformer inside as well for AC-DC sets. It makes things a lot easier to have all of this inside one reasonably sized cabinet, and no possibility of damaging the bulbs.

Clint, VE3CMQ

From: Amateur-repairs@groups.io <Amateur-repairs@groups.io> On Behalf Of Don VE3IDS via groups.io
Sent: Sunday, 24 December 2023 10:53
To: Amateur-repairs@groups.io
Subject: Re: [Amateur-repairs] SETTING UP A TEST BENCH

Dan,

Look for " Rough Service Bulbs ". They are still available and are incandescent. A plus is the filament is better supported for knocking around and are usually rated for a little higher voltage ~130. Farm supply stores should have them if the big box stores don't.

73 Don ve3ids

Sunday, 24 December 2023

Re: [Amateur-repairs] SETTING UP A TEST BENCH

For the large Dim-bulb user- Amazon.

Gary

On 12/24/2023 10:23 AM, Dan wrote:

My startup rig is a 20A Powerstat variac, re-fused down to an appropriate level, a dim bulb tester, and a Kill-A-Watt meter, then the device under test. Works well. The Kill-A-Watt meter has to be slightly modified to display values at low AC input voltages.    Can you even buy incandescent A19/E26 base incandescent bulbs anymore? Maybe Amazon?    Dan  WB4GRA

On Dec 24, 2023, at 10:43 AM, Jim Shorney <jimNU0C@gmail.com> wrote:      Another thing worth noting is that makers of variacs often skip putting a fuse on the output side. Think about transformer theory and you will see why this is important.    73    -Jim  NU0C

On Sun, 24 Dec 2023 09:03:18 -0500  "Tim Reimers KA4LFP" <treimers95@gmail.com> wrote:    "A good rheostat for slowly powering up something that make have been turn  off for the last 20, 30, 40 years."      Couple of points here  A Variac (what you're talking about when you say rheostat)  Does NOT LIMIT CURRENT.  A dead short in a DUT will still destroy components like the DUTs power  transformer, even sometimes at the low voltage a variac provides.    Also, a Variac does not protect you from the AC line. A large (massive)  number of old shortwave radios and other audio gear had "hot chassis"  designs, with no power transformer, and the chassis was physically isolated  from the case.  A so-called AC-AC design.        Best design for a power system for your bench:    Separate GFCI circuit feeding a large isolation transformer, in series with  a Dim Bulb Tester in series with the Variac.    The Dim Bulb Tester does limit current to protect you from those dead  shorted dried out capacitors that will let all the unobtanium smoke out of  your power transformer.    73, Tim KA4LFP            Morse Code: The original digital mode.

      --    73    -Jim  NU0C

Re: [Amateur-repairs] SETTING UP A TEST BENCH

Most of mine are PowerStat variable auto-transformers, many are open, sized from about 110VA to 2+Kva , fed thru a GFCI, and should be fuses for that specific gadget under test, but a lot depends on what you are doing with what, and the situation is with it .

From: Amateur-repairs@groups.io [mailto:Amateur-repairs@groups.io] On Behalf Of bobcolenso via groups.io
Sent: Sunday, December 24, 2023 11:05 AM
To: Amateur-repairs@groups.io
Subject: Re: [Amateur-repairs] SETTING UP A TEST BENCH

Yep, I stand corrected! Variac, not rheostat.
--

Bob
KD8WU

Re: [Amateur-repairs] SETTING UP A TEST BENCH

Dan,

73 Don ve3ids

On Sun., Dec. 24, 2023, 11:23 a.m. Dan, <pitfit@comcast.net> wrote:

My startup rig is a 20A Powerstat variac, re-fused down to an appropriate level, a dim bulb tester, and a Kill-A-Watt meter, then the device under test. Works well. The Kill-A-Watt meter has to be slightly modified to display values at low AC input voltages.

Can you even buy incandescent A19/E26 base incandescent bulbs anymore? Maybe Amazon?

Dan
WB4GRA
> On Dec 24, 2023, at 10:43 AM, Jim Shorney <jimNU0C@gmail.com> wrote:
>
>
> Another thing worth noting is that makers of variacs often skip putting a fuse on the output side. Think about transformer theory and you will see why this is important.
>
> 73
>
> -Jim
> NU0C
>
>> On Sun, 24 Dec 2023 09:03:18 -0500
>> "Tim Reimers KA4LFP" <treimers95@gmail.com> wrote:
>>
>> "A good rheostat for slowly powering up something that make have been turn
>> off for the last 20, 30, 40 years."
>>
>>
>> Couple of points here
>> A Variac (what you're talking about when you say rheostat)
>> Does NOT LIMIT CURRENT.
>> A dead short in a DUT will still destroy components like the DUTs power
>> transformer, even sometimes at the low voltage a variac provides.
>>
>> Also, a Variac does not protect you from the AC line. A large (massive)
>> number of old shortwave radios and other audio gear had "hot chassis"
>> designs, with no power transformer, and the chassis was physically isolated
>> from the case.
>> A so-called AC-AC design.
>>
>>
>>
>> Best design for a power system for your bench:
>>
>> Separate GFCI circuit feeding a large isolation transformer, in series with
>> a Dim Bulb Tester in series with the Variac.
>>
>> The Dim Bulb Tester does limit current to protect you from those dead
>> shorted dried out capacitors that will let all the unobtanium smoke out of
>> your power transformer.
>>
>> 73, Tim KA4LFP
>>
>>
>>
>>
>>
>> Morse Code: The original digital mode.
>>
>>
>>
>>
>>
>
>
>
> --
>
> 73
>
> -Jim
> NU0C
>
>
>
>
>

_._,_._,_

Groups.io Links:

You receive all messages sent to this group.

_._,_._,_

Re: [Amateur-repairs] SETTING UP A TEST BENCH

My startup rig is a 20A Powerstat variac, re-fused down to an appropriate level, a dim bulb tester, and a Kill-A-Watt meter, then the device under test. Works well. The Kill-A-Watt meter has to be slightly modified to display values at low AC input voltages.

Can you even buy incandescent A19/E26 base incandescent bulbs anymore? Maybe Amazon?

Dan
WB4GRA
> On Dec 24, 2023, at 10:43 AM, Jim Shorney <jimNU0C@gmail.com> wrote:
>
>
> Another thing worth noting is that makers of variacs often skip putting a fuse on the output side. Think about transformer theory and you will see why this is important.
>
> 73
>
> -Jim
> NU0C
>
>> On Sun, 24 Dec 2023 09:03:18 -0500
>> "Tim Reimers KA4LFP" <treimers95@gmail.com> wrote:
>>
>> "A good rheostat for slowly powering up something that make have been turn
>> off for the last 20, 30, 40 years."
>>
>>
>> Couple of points here
>> A Variac (what you're talking about when you say rheostat)
>> Does NOT LIMIT CURRENT.
>> A dead short in a DUT will still destroy components like the DUTs power
>> transformer, even sometimes at the low voltage a variac provides.
>>
>> Also, a Variac does not protect you from the AC line. A large (massive)
>> number of old shortwave radios and other audio gear had "hot chassis"
>> designs, with no power transformer, and the chassis was physically isolated
>> from the case.
>> A so-called AC-AC design.
>>
>>
>>
>> Best design for a power system for your bench:
>>
>> Separate GFCI circuit feeding a large isolation transformer, in series with
>> a Dim Bulb Tester in series with the Variac.
>>
>> The Dim Bulb Tester does limit current to protect you from those dead
>> shorted dried out capacitors that will let all the unobtanium smoke out of
>> your power transformer.
>>
>> 73, Tim KA4LFP
>>
>>
>>
>>
>>
>> Morse Code: The original digital mode.
>>
>>
>>
>>
>>
>
>
>
> --
>
> 73
>
> -Jim
> NU0C
>
>
>
>
>

-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#90890): https://groups.io/g/Amateur-repairs/message/90890
Mute This Topic: https://groups.io/mt/102090237/693790
Group Owner: Amateur-repairs+owner@groups.io
Unsubscribe: https://groups.io/g/Amateur-repairs/leave/4530700/693790/458576413/xyzzy [jhjoshan@gmail.com]
-=-=-=-=-=-=-=-=-=-=-=-

Re: [Amateur-repairs] SETTING UP A TEST BENCH

Yep, I stand corrected! Variac, not rheostat.
--

Bob
KD8WU

_._,_._,_

Groups.io Links:

You receive all messages sent to this group.

_._,_._,_

Re: [Amateur-repairs] SETTING UP A TEST BENCH

Another thing worth noting is that makers of variacs often skip putting a fuse on the output side. Think about transformer theory and you will see why this is important.

73

-Jim
NU0C

On Sun, 24 Dec 2023 09:03:18 -0500
"Tim Reimers KA4LFP" <treimers95@gmail.com> wrote:

> "A good rheostat for slowly powering up something that make have been turn
> off for the last 20, 30, 40 years."
>
>
> Couple of points here
> A Variac (what you're talking about when you say rheostat)
> Does NOT LIMIT CURRENT.
> A dead short in a DUT will still destroy components like the DUTs power
> transformer, even sometimes at the low voltage a variac provides.
>
> Also, a Variac does not protect you from the AC line. A large (massive)
> number of old shortwave radios and other audio gear had "hot chassis"
> designs, with no power transformer, and the chassis was physically isolated
> from the case.
> A so-called AC-AC design.
>
>
>
> Best design for a power system for your bench:
>
> Separate GFCI circuit feeding a large isolation transformer, in series with
> a Dim Bulb Tester in series with the Variac.
>
> The Dim Bulb Tester does limit current to protect you from those dead
> shorted dried out capacitors that will let all the unobtanium smoke out of
> your power transformer.
>
> 73, Tim KA4LFP
>
>
>
>
>
> Morse Code: The original digital mode.
>
>
>
>
>

--

73

-Jim
NU0C

-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#90888): https://groups.io/g/Amateur-repairs/message/90888
Mute This Topic: https://groups.io/mt/102090237/693790
Group Owner: Amateur-repairs+owner@groups.io
Unsubscribe: https://groups.io/g/Amateur-repairs/leave/4530700/693790/458576413/xyzzy [jhjoshan@gmail.com]
-=-=-=-=-=-=-=-=-=-=-=-

Re: [Amateur-repairs] SETTING UP A TEST BENCH

Excellent advice.

Gary

On 12/24/2023 8:03 AM, Tim Reimers KA4LFP wrote:

"A good rheostat for slowly powering up something that make have been turn off for the last 20, 30, 40 years."

Couple of points here

A Variac (what you're talking about when you say rheostat)

Does NOT LIMIT CURRENT.

A dead short in a DUT will still destroy components like the DUTs power transformer, even sometimes at the low voltage a variac provides.

Also, a Variac does not protect you from the AC line. A large (massive) number of old shortwave radios and other audio gear had "hot chassis" designs, with no power transformer, and the chassis was physically isolated from the case.

A so-called AC-AC design.

Best design for a power system for your bench:

Separate GFCI circuit feeding a large isolation transformer, in series with a Dim Bulb Tester in series with the Variac.

The Dim Bulb Tester does limit current to protect you from those dead shorted dried out capacitors that will let all the unobtanium smoke out of your power transformer.

73, Tim KA4LFP

Morse Code: The original digital mode.

Re: [Amateur-repairs] SETTING UP A TEST BENCH

"A good rheostat for slowly powering up something that make have been turn off for the last 20, 30, 40 years."

Couple of points here

A Variac (what you're talking about when you say rheostat)

Does NOT LIMIT CURRENT.

A dead short in a DUT will still destroy components like the DUTs power transformer, even sometimes at the low voltage a variac provides.

Also, a Variac does not protect you from the AC line. A large (massive) number of old shortwave radios and other audio gear had "hot chassis" designs, with no power transformer, and the chassis was physically isolated from the case.

A so-called AC-AC design.

Best design for a power system for your bench:

Separate GFCI circuit feeding a large isolation transformer, in series with a Dim Bulb Tester in series with the Variac.

The Dim Bulb Tester does limit current to protect you from those dead shorted dried out capacitors that will let all the unobtanium smoke out of your power transformer.

73, Tim KA4LFP

Morse Code: The original digital mode.

_._,_._,_

Groups.io Links:

You receive all messages sent to this group.

_._,_._,_

Re: [Amateur-repairs] SETTING UP A TEST BENCH

One thing on my To-Do list is to install a dedicated power outlet for the Unit Under Test, a power consumption meter like a "Kill A Watt", and a BIG E-STOP button.

A good rheostat for slowly powering up something that make have been turn off for the last 20, 30, 40 years.

Besides ham radio stuff, I've been contemplating vintage audio equipment and what I would need for that. 8Ω dummy loads, AF power meter, AF spectrum analyzer (?)
--

Bob
KD8WU

_._,_._,_

Groups.io Links:

You receive all messages sent to this group.

_._,_._,_

Saturday, 23 December 2023

Re: [Amateur-repairs] SETTING UP A TEST BENCH

Thanks, Bob KD8WU, for your thoughts. I, too, have eyes that are getting older. "Setting up a test bench" to me is one of the "fun" things to do during inclement weather - or when something new needs to be done - or when you're going a bit nutty because you're feeling a bit lazy and stuck inside. Let us know how it's going. I'm interested in seeing other hams' workspaces.

Dave W9OCM

Fairmount, IN 46928

On Sat, Dec 23, 2023 at 6:59 AM bobcolenso via groups.io <bobcolenso=yahoo.com@groups.io> wrote:

All this is giving me some ideas also. I like the big screen TV for reading schematics. My eyes are starting to get old.

A lot of people have mentioned a good soldering iron(s). This is very important! Mine is variable up to 750° or so, But I also have different size tips, normal for regular PCB components, and a BIG tip for things that have more thermal mass.

My sig gen is an HP-8648C has more than what I really need (9K to 3G, -139 dBm to +14.5 dBm) [Below 30 MHz S9 is defined as -73 dBm, S1 is -121 dBm, so you want that covered. 40 over S9 is a pretty strong signal AT -33dBm]

Don't go with an elCheapo multimeter with a dial and a needle, you'll get elCheapo results. Get something decent. I have a Boonton 92C, it's an RF mV meter calibrated to 700 MHz has a max full scale of 3 volts, the bottom FS is 3mV and I can read 250, maybe 100 µV.

Also a VTVM for peaking and nulling non-RF levels. Here I use an HP-410-C, which is actually a transistorized VTVM.

A good Frequency Counter.

One thing I just got is a 0 to 450 volt power supply. This I can use on spare part electrolytic caps sitting around.

On the want list is another dummy load and coax so I can put it in the far corner of the basement.

One thing you can do is look at web sites of people who work on radios and see what they use and get ideas from there. You know what you want to do with it, you know your skill level, ect.

Above all; HAVE FUN!

--

Bob
KD8WU

_._,_._,_

Groups.io Links:

You receive all messages sent to this group.

_._,_._,_

Re: [Amateur-repairs] SETTING UP A TEST BENCH

All this is giving me some ideas also. I like the big screen TV for reading schematics. My eyes are starting to get old.

A lot of people have mentioned a good soldering iron(s). This is very important! Mine is variable up to 750° or so, But I also have different size tips, normal for regular PCB components, and a BIG tip for things that have more thermal mass.

My sig gen is an HP-8648C has more than what I really need (9K to 3G, -139 dBm to +14.5 dBm) [Below 30 MHz S9 is defined as -73 dBm, S1 is -121 dBm, so you want that covered. 40 over S9 is a pretty strong signal AT -33dBm]

Don't go with an elCheapo multimeter with a dial and a needle, you'll get elCheapo results. Get something decent. I have a Boonton 92C, it's an RF mV meter calibrated to 700 MHz has a max full scale of 3 volts, the bottom FS is 3mV and I can read 250, maybe 100 µV.

Also a VTVM for peaking and nulling non-RF levels. Here I use an HP-410-C, which is actually a transistorized VTVM.

A good Frequency Counter.

One thing I just got is a 0 to 450 volt power supply. This I can use on spare part electrolytic caps sitting around.

On the want list is another dummy load and coax so I can put it in the far corner of the basement.

One thing you can do is look at web sites of people who work on radios and see what they use and get ideas from there. You know what you want to do with it, you know your skill level, ect.

Above all; HAVE FUN!

--

Bob
KD8WU

_._,_._,_

Groups.io Links:

You receive all messages sent to this group.

_._,_._,_

Sunday, 31 December 2023

Monday, 25 December 2023

Sunday, 24 December 2023

BobKD8WU

BobKD8WU

BobKD8WU

Saturday, 23 December 2023

BobKD8WU

BobKD8WU

Bob
KD8WU

Bob
KD8WU

Bob
KD8WU

Bob
KD8WU

Bob
KD8WU