Anyone think of a rigid, easily-ground non-ferrous material, commonly
available which could be fashioned into a screwdriver blade of about
1mmx 0.25mm section?

On Mon, 19 Dec 2022 11:48:37 +1100, Cursitor Doom <cd@notformail.com>
wrote:

> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> available which could be fashioned into a screwdriver blade of about
> 1mmx 0.25mm section?

Aluminium if you just want to be able to tweek a slug in a coil.

On Mon, 19 Dec 2022 11:59:37 +1100, chop <chop654@gmail.com> wrote:

> On Mon, 19 Dec 2022 11:48:37 +1100, Cursitor Doom <cd@notformail.com>
> wrote:
>
>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>> available which could be fashioned into a screwdriver blade of about
>> 1mmx 0.25mm section?
>
> Aluminium if you just want to be able to tweek a slug in a coil.

Or a rigid plastic.

But you can buy tuning things for coil slugs.

On 19/12/2022 00:48, Cursitor Doom wrote:
> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> available which could be fashioned into a screwdriver blade of about
> 1mmx 0.25mm section?

There are a number of uses for non-magnetic and spark-proof
screwdrivers, such as for the watch and clock trade, as well as others.

They're not always cheap though.

On 19/12/2022 00:48, Cursitor Doom wrote:
> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> available which could be fashioned into a screwdriver blade of about
> 1mmx 0.25mm section?
you don't have any?....shocking

On 19/12/2022 00:48, Cursitor Doom wrote:
> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> available which could be fashioned into a screwdriver blade of about
> 1mmx 0.25mm section?

Spaghetti.

--
Cheers
Clive

On 19/12/2022 08:41, Clive Arthur wrote:
> On 19/12/2022 00:48, Cursitor Doom wrote:
>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>> available which could be fashioned into a screwdriver blade of about
>> 1mmx 0.25mm section?
>
> Spaghetti.
>
Presumably the dried kind?

We used to use plastic knitting needles. However be aware that if we are
talking vintage radios etc, then some cores had hex holes all the way
through, allowing the real nylon tool to pass through the nearest core and
tweak the lower one and of course vice versa. This is needed to get proper
band pass tuning. You need a sweep generator and a scope of course to do
the alignment correctly, with proper crystal frequency markers to make sure
the 3dB down points are in the right place.
Of course older cores can get stuck or broken, so I wish you luck.

Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Cursitor Doom" <cd@notformail.com> wrote in message
news:21dvph1ggr27qrhemgl9ttct3i011g03au@4ax.com...
> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> available which could be fashioned into a screwdriver blade of about
> 1mmx 0.25mm section?

In the main one needs to consider why something needs to be realigned.
Normally cores in coils tend not to move unless there is excessive vibration
over the years, but sometimes small capacitors in or around coils can go
faulty, and need replacement with new ones. Then you can realign the IF
strip. Often there are band pass double coil systems to keep the audio
reasonable on AM, and cores do tend to get stuck. So be extremely careful as
the cores are very easy to chip or break.
If its a normal AM radio, you may need to align the aerial coil and
capacitors as well so the gain is reasonable over the band. Some are better
than others in this regard, but make sure once you have dont the coil at the
low end and the capacitor at the high end it does not have a dead spot in
the middle. You can literally spend ours on changing the gain points to
track it as good as you can.
The oscillator often does drift a little so always test the stations near
band edge are still receivable.
Of cours if its an FM tuner thing can be different, the old school system
was much the same as just discussed except instead of around 455Khz for the
IF its likely to be 10.7Mhz and because of the way fm is detected, alignment
may mean using an alternative detector to see what is going on, but apart
from that the principals are the same.
A lot of tuners and small portables were made using single chips, and
although it may look a bit odd, often the actual circuits were very similar
but ceramic filters could be used instead of coils in some places.
These, assuming they are not faulty tend to be very lop sided in the way
they roll off, but you need to use their frequency to align coils to try to
achieve an equal roll off each side.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Andy Bennett" <aben@ben37j.com> wrote in message
news:z9WnL.2268015$SIb3.144092@fx05.ams4...
> On 19/12/2022 08:41, Clive Arthur wrote:
>> On 19/12/2022 00:48, Cursitor Doom wrote:
>>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>>> available which could be fashioned into a screwdriver blade of about
>>> 1mmx 0.25mm section?
>>
>> Spaghetti.
>>
> Presumably the dried kind?
>

On 19/12/2022 00:48, Cursitor Doom wrote:
> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> available which could be fashioned into a screwdriver blade of about
> 1mmx 0.25mm section?

Back in the day we used plastic knitting needles, those being a common
item in many homes.
Another option is a kebab skewer or cocktail stick. soak the end in
superglue to stiffen it, as the actress said to the bishop..
The purpose made ones I used to have had little bronze leaves in the end
of a thermoplastic rod. I also had nylon one with hex ends for some of
the slugs that had hex holes

--
“It is hard to imagine a more stupid decision or more dangerous way of
making decisions than by putting those decisions in the hands of people
who pay no price for being wrong.”

Thomas Sowell

On Monday, 19 December 2022 at 10:23:27 UTC, Brian Gaff wrote:
> In the main one needs to consider why something needs to be realigned.
> Normally cores in coils tend not to move unless there is excessive vibration
> over the years, but sometimes small capacitors in or around coils can go
> faulty, and need replacement with new ones. Then you can realign the IF
> strip. Often there are band pass double coil systems to keep the audio
> reasonable on AM, and cores do tend to get stuck. So be extremely careful as
> the cores are very easy to chip or break.
> If its a normal AM radio, you may need to align the aerial coil and
> capacitors as well so the gain is reasonable over the band. Some are better
> than others in this regard, but make sure once you have dont the coil at the
> low end and the capacitor at the high end it does not have a dead spot in
> the middle. You can literally spend ours on changing the gain points to
> track it as good as you can.
> The oscillator often does drift a little so always test the stations near
> band edge are still receivable.
> Of cours if its an FM tuner thing can be different, the old school system
> was much the same as just discussed except instead of around 455Khz for the
> IF its likely to be 10.7Mhz and because of the way fm is detected, alignment
> may mean using an alternative detector to see what is going on, but apart
> from that the principals are the same.
> A lot of tuners and small portables were made using single chips, and
> although it may look a bit odd, often the actual circuits were very similar
> but ceramic filters could be used instead of coils in some places.
> These, assuming they are not faulty tend to be very lop sided in the way
> they roll off, but you need to use their frequency to align coils to try to
> achieve an equal roll off each side.
> Brian
Thanks Brian. Interesting.

Bill

On Mon, 19 Dec 2022 07:57:13 +0000, "jim.gm4dhj"
<kinvig.netta@ntlworld.com> wrote:

>On 19/12/2022 00:48, Cursitor Doom wrote:
>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>> available which could be fashioned into a screwdriver blade of about
>> 1mmx 0.25mm section?
>you don't have any?....shocking

The ones I have aren't a very good fit for these cores and I don't
feel like taking a chance on 50 year old cores. I would normally order
some, but given the Xmas post and all the rest of the mess right now,
I'm going to roll my own this time and go for a nice, snug, bespoke
fit.

On 19/12/2022 16:38, Cursitor Doom wrote:
> On Mon, 19 Dec 2022 07:57:13 +0000, "jim.gm4dhj"
> <kinvig.netta@ntlworld.com> wrote:
>
>> On 19/12/2022 00:48, Cursitor Doom wrote:
>>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>>> available which could be fashioned into a screwdriver blade of about
>>> 1mmx 0.25mm section?
>> you don't have any?....shocking
>
> The ones I have aren't a very good fit for these cores and I don't
> feel like taking a chance on 50 year old cores. I would normally order
> some, but given the Xmas post and all the rest of the mess right now,
> I'm going to roll my own this time and go for a nice, snug, bespoke
> fit.
As I said, any plastic rod...and a nailfile...

--
If I had all the money I've spent on drink...
...I'd spend it on drink.

Sir Henry (at Rawlinson's End)

On Mon, 19 Dec 2022 10:23:21 -0000, "Brian Gaff"
<brian1gaff@gmail.com> wrote:

>In the main one needs to consider why something needs to be realigned.
>Normally cores in coils tend not to move unless there is excessive vibration
>over the years, but sometimes small capacitors in or around coils can go
>faulty, and need replacement with new ones. Then you can realign the IF
>strip. Often there are band pass double coil systems to keep the audio
>reasonable on AM, and cores do tend to get stuck. So be extremely careful as
>the cores are very easy to chip or break.
> If its a normal AM radio, you may need to align the aerial coil and
>capacitors as well so the gain is reasonable over the band. Some are better
>than others in this regard, but make sure once you have dont the coil at the
>low end and the capacitor at the high end it does not have a dead spot in
>the middle. You can literally spend ours on changing the gain points to
>track it as good as you can.
> The oscillator often does drift a little so always test the stations near
>band edge are still receivable.
> Of cours if its an FM tuner thing can be different, the old school system
>was much the same as just discussed except instead of around 455Khz for the
>IF its likely to be 10.7Mhz and because of the way fm is detected, alignment
>may mean using an alternative detector to see what is going on, but apart
>from that the principals are the same.
> A lot of tuners and small portables were made using single chips, and
>although it may look a bit odd, often the actual circuits were very similar
>but ceramic filters could be used instead of coils in some places.
> These, assuming they are not faulty tend to be very lop sided in the way
>they roll off, but you need to use their frequency to align coils to try to
>achieve an equal roll off each side.
> Brian

Sounds like you know what you're on about here, Brian.
I know there are differing philosophies when it comes to realignment.
I keep a ton of high-end test equipment which comes in handy as I
already have everything I need. I like to go through stage by stage
with a sweep generator and examine the outputs of each with a spectrum
analyser to get the 'humps' of the passband all evenly distributed
around the relevant IF. People who just go through the stages peaking
each core for maximum volume risk sending the thing into feedback -
and ending up with such a narrow 'sweet spot' that the slightest
temperature change will knock the receiver off, requiring frequent
re-twiddling of the tuning knob. Worst of all are the screwdriver
jockeys who leave a trail of fractured and jammed pot-cores in their
wake. Grrrrr!!

On Mon, 19 Dec 2022 16:42:17 +0000, The Natural Philosopher
<tnp@invalid.invalid> wrote:

>On 19/12/2022 16:38, Cursitor Doom wrote:
>> On Mon, 19 Dec 2022 07:57:13 +0000, "jim.gm4dhj"
>> <kinvig.netta@ntlworld.com> wrote:
>>
>>> On 19/12/2022 00:48, Cursitor Doom wrote:
>>>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>>>> available which could be fashioned into a screwdriver blade of about
>>>> 1mmx 0.25mm section?
>>> you don't have any?....shocking
>>
>> The ones I have aren't a very good fit for these cores and I don't
>> feel like taking a chance on 50 year old cores. I would normally order
>> some, but given the Xmas post and all the rest of the mess right now,
>> I'm going to roll my own this time and go for a nice, snug, bespoke
>> fit.
>As I said, any plastic rod...and a nailfile...

I like the idea of the plastic knitting needle Brian mentioned. I
think that should do the trick and I do have an emporium for
haberdashery items within walking distance...

Cursitor Doom <cd@notformail.com> wrote:
> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> available which could be fashioned into a screwdriver blade of about
> 1mmx 0.25mm section?
>

You can buy them for not much. Try EBay. Typically they are double ended
with bronze blades.

On 19/12/2022 20:34, Cursitor Doom wrote:
> On Mon, 19 Dec 2022 16:42:17 +0000, The Natural Philosopher
> <tnp@invalid.invalid> wrote:
>
>> On 19/12/2022 16:38, Cursitor Doom wrote:
>>> On Mon, 19 Dec 2022 07:57:13 +0000, "jim.gm4dhj"
>>> <kinvig.netta@ntlworld.com> wrote:
>>>
>>>> On 19/12/2022 00:48, Cursitor Doom wrote:
>>>>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>>>>> available which could be fashioned into a screwdriver blade of about
>>>>> 1mmx 0.25mm section?
>>>> you don't have any?....shocking
>>>
>>> The ones I have aren't a very good fit for these cores and I don't
>>> feel like taking a chance on 50 year old cores. I would normally order
>>> some, but given the Xmas post and all the rest of the mess right now,
>>> I'm going to roll my own this time and go for a nice, snug, bespoke
>>> fit.
>> As I said, any plastic rod...and a nailfile...
>
> I like the idea of the plastic knitting needle Brian mentioned.

I mentioned it actually.

I
> think that should do the trick and I do have an emporium for
> haberdashery items within walking distance...

That is a rare and valuable thing.

I generally use ebay or amazon

--
No Apple devices were knowingly used in the preparation of this post.

On 19/12/2022 21:26, Brian wrote:
> Cursitor Doom <cd@notformail.com> wrote:
>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>> available which could be fashioned into a screwdriver blade of about
>> 1mmx 0.25mm section?
>>
>
> You can buy them for not much. Try EBay. Typically they are double ended
> with bronze blades.
>
>
>
Very helpful as usual Mr Reay....good man

On Mon, 19 Dec 2022 21:26:52 -0000 (UTC), Brian <noinv@lid.org> wrote:

>Cursitor Doom <cd@notformail.com> wrote:
>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>> available which could be fashioned into a screwdriver blade of about
>> 1mmx 0.25mm section?
>>
>
>You can buy them for not much. Try EBay. Typically they are double ended
>with bronze blades.

Take a month of Sundays to arrive at this time of year. Hence the
original question. And this is supposed to be a DIY group!

>
>

In message <r644qhpl58o239d8ue0e0cbbltf13tml9o@4ax.com>, Cursitor Doom
<cd@notformail.com> writes
>On Mon, 19 Dec 2022 21:26:52 -0000 (UTC), Brian <noinv@lid.org> wrote:
>
>>Cursitor Doom <cd@notformail.com> wrote:
>>> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>>> available which could be fashioned into a screwdriver blade of about
>>> 1mmx 0.25mm section?
>>>
>>
>>You can buy them for not much. Try EBay. Typically they are double ended
>>with bronze blades.
>
>Take a month of Sundays to arrive at this time of year. Hence the
>original question. And this is supposed to be a DIY group!

Find an elderly female neighbour?

--
Tim Lamb

On Tuesday, 20 December 2022 at 19:46:36 UTC, Cursitor Doom wrote:
> On Mon, 19 Dec 2022 21:26:52 -0000 (UTC), Brian <no...@lid.org> wrote:
>
> >Cursitor Doom <c...@notformail.com> wrote:
> >> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> >> available which could be fashioned into a screwdriver blade of about
> >> 1mmx 0.25mm section?
> >>
> >
> >You can buy them for not much. Try EBay. Typically they are double ended
> >with bronze blades.
> Take a month of Sundays to arrive at this time of year. Hence the
> original question. And this is supposed to be a DIY group!

diy something then. You know what materials work & what you have. The only thing I don't recall mentioned was epoxy & fibre, either glass or paper.

Last one I fixed had all its cores firmly seized. Turned out its sensitivity problem lay elsewhere & it didn't need a tweak. Did not want to rebuild the cans. Had already worked out a sneakaround but not needed.

On Tue, 20 Dec 2022 13:43:38 -0800 (PST), Animal <tabbypurr@gmail.com>
wrote:

>On Tuesday, 20 December 2022 at 19:46:36 UTC, Cursitor Doom wrote:
>> On Mon, 19 Dec 2022 21:26:52 -0000 (UTC), Brian <no...@lid.org> wrote:
>>
>> >Cursitor Doom <c...@notformail.com> wrote:
>> >> Anyone think of a rigid, easily-ground non-ferrous material, commonly
>> >> available which could be fashioned into a screwdriver blade of about
>> >> 1mmx 0.25mm section?
>> >>
>> >
>> >You can buy them for not much. Try EBay. Typically they are double ended
>> >with bronze blades.
>> Take a month of Sundays to arrive at this time of year. Hence the
>> original question. And this is supposed to be a DIY group!
>
>diy something then. You know what materials work & what you have. The only thing I don't recall mentioned was epoxy & fibre, either glass or paper.
>
>Last one I fixed had all its cores firmly seized. Turned out its sensitivity problem lay elsewhere & it didn't need a tweak. Did not want to rebuild the cans. Had already worked out a sneakaround but not needed.

The problem with seized cores is that the inductors they tune are
typically in parallel with a fixed capacitance. So even though the
cores have never gone out of adjustment (cos they're seized) the value
of the capacitances they resonate with will have done - and those caps
are not adjustable. So in order to re-align that stage, you have to
somehow free those cores. There's no practical alternative and if you
have to destroy and replace them in the process, then so be it.

On Saturday, 24 December 2022 at 14:56:45 UTC, Cursitor Doom wrote:
> On Tue, 20 Dec 2022 13:43:38 -0800 (PST), Animal <tabb...@gmail.com>
> wrote:
> >On Tuesday, 20 December 2022 at 19:46:36 UTC, Cursitor Doom wrote:
> >> On Mon, 19 Dec 2022 21:26:52 -0000 (UTC), Brian <no...@lid.org> wrote:
> >>
> >> >Cursitor Doom <c...@notformail.com> wrote:
> >> >> Anyone think of a rigid, easily-ground non-ferrous material, commonly
> >> >> available which could be fashioned into a screwdriver blade of about
> >> >> 1mmx 0.25mm section?
> >> >>
> >> >
> >> >You can buy them for not much. Try EBay. Typically they are double ended
> >> >with bronze blades.
> >> Take a month of Sundays to arrive at this time of year. Hence the
> >> original question. And this is supposed to be a DIY group!
> >
> >diy something then. You know what materials work & what you have. The only thing I don't recall mentioned was epoxy & fibre, either glass or paper.
> >
> >Last one I fixed had all its cores firmly seized. Turned out its sensitivity problem lay elsewhere & it didn't need a tweak. Did not want to rebuild the cans. Had already worked out a sneakaround but not needed.
> The problem with seized cores is that the inductors they tune are
> typically in parallel with a fixed capacitance. So even though the
> cores have never gone out of adjustment (cos they're seized) the value
> of the capacitances they resonate with will have done - and those caps
> are not adjustable. So in order to re-align that stage, you have to
> somehow free those cores. There's no practical alternative and if you
> have to destroy and replace them in the process, then so be it.

The practical alternative I came up with was gimmick caps. But not needed. Realignment may be popular, but is not always needed, as in this case.

On Mon, 19 Dec 2022 10:06:21 -0000, "Brian Gaff"
<brian1gaff@gmail.com> wrote:

>We used to use plastic knitting needles. However be aware that if we are
>talking vintage radios etc, then some cores had hex holes all the way
>through, allowing the real nylon tool to pass through the nearest core and
>tweak the lower one and of course vice versa. This is needed to get proper
>band pass tuning. You need a sweep generator and a scope of course to do
>the alignment correctly, with proper crystal frequency markers to make sure
>the 3dB down points are in the right place.

That's a bit "old school", Brian. For £60 and upwards you can get a
Chinese nanoVNA which will do all of that and much more besides.

> Of course older cores can get stuck or broken, so I wish you luck.
>
>Brian