On Sun, 16 Nov 2003 09:49:49 -0800, Bill Turner
wrote:

On Sun, 16 Nov 2003 14:45:47 GMT, "Michael A. Terrell"
wrote:

I told
the cal lab the label should read, "Calibration not possible". ;-)
--

_________________________________________________ ________

LOL!

--
Bill, W6WRT


A decade ago I had a struggle with those instruments idiots referring
to ISO 9000, had an old fully working 30 years old Wande&Goltermann
SPM-1 instrument for telex channels, with mark and space marked, but
they would give me a new digital possibly from HP, costing in the
region of $10000 - without the channel marks, but solid state. After a
dispute they agreed to check the calibration, and it was better than
they could measure, so they had to let it pass, but I damaged their
day!

I was told that if any tubes broke down it was forbidden to change
them, and it was a political decision to discard such old instruments

73
Jan-Martin
LA8AK
http://home.online.no/~la8ak/c.htm
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On Sun, 16 Nov 2003 09:49:49 -0800, Bill Turner
wrote:

On Sun, 16 Nov 2003 14:45:47 GMT, "Michael A. Terrell"
wrote:

I told
the cal lab the label should read, "Calibration not possible". ;-)
--

_________________________________________________ ________

LOL!

--
Bill, W6WRT


A decade ago I had a struggle with those instruments idiots referring
to ISO 9000, had an old fully working 30 years old Wande&Goltermann
SPM-1 instrument for telex channels, with mark and space marked, but
they would give me a new digital possibly from HP, costing in the
region of $10000 - without the channel marks, but solid state. After a
dispute they agreed to check the calibration, and it was better than
they could measure, so they had to let it pass, but I damaged their
day!

I was told that if any tubes broke down it was forbidden to change
them, and it was a political decision to discard such old instruments

73
Jan-Martin
LA8AK
http://home.online.no/~la8ak/c.htm
--
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On Sun, 16 Nov 2003 13:27:49 +0000, Paul Burridge
wrote:

On Sat, 15 Nov 2003 17:23:50 -0600 (CST), (Bill
Turner) wrote:

THERE MUST HAVE BEEN SOMETHING WRONG WITH YOUR MILLEN. BILL T.

I'm not using a Millen and this post isn't a troll as someone else
suggested. The meter I use started out life as a Tradiper (Japanese)
but because it was hopelessly outdated and used old germanium trannies
with enough lead inductance to tune a VoA transmitter, I decided to
rip its guts out and rebuild from scratch.

sorry I don't really see your point. I bought my Tradipper in 67, and
it has been very useful since then, I may not use it so often now
because I've also got a Philips GM3121.
Mine operatet satisfactorily - as original - up to 140MHz, but the 2M
coil is no coil at all, only a short between to pins on the connector.
Have described how to improve on this on
http://home.online.no/~la8ak/m2.htm

The other modification is to use external +12V since the battery would
normally be flat when needed, but the original version had "positive-
ground", and some minor changes had to be done

LA3JA later bought the same model, but this had a very bad
intermittent contact in the tuning capacitor, so I couldn't repair it.

DL7QY described a dipmeter covering up to 1GHz, but I haven't really
felt I needed it because it is other ways to check ressonance than
using a GDM, and 1GHz is still not the highest frequency I need to
cover

73
Jan-Martin, LA8AK
http://home.online.no/~la8ak/c.htm
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On Sun, 16 Nov 2003 09:48:50 -0800, Bill Turner
wrote:

On 16 Nov 2003 16:56:27 GMT, (Michael Black)
wrote:

I'd
certainly put in a buffer for an output, as a signal generator or to feed
a frequency counter. The latter then means the dial doesn't require much
effort, and the readout will be much much better than any GDO from before.

_________________________________________________ ________

This would be a good way to go in the sense of not requiring a
calibrated dial, but a GDO is necessarily a broadly tuned device simply
because a single tank circuit is a broadly tuned device. A high degree
of precision is neither needed nor even possible.

....because frequency it is pulled when dip occurs and when you adjust
excitation for best reading on the meter

Still, I like the concept.

--
Bill, W6WRT


73
LA8AK
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On Sun, 16 Nov 2003 09:48:50 -0800, Bill Turner
wrote:

On 16 Nov 2003 16:56:27 GMT, (Michael Black)
wrote:

I'd
certainly put in a buffer for an output, as a signal generator or to feed
a frequency counter. The latter then means the dial doesn't require much
effort, and the readout will be much much better than any GDO from before.

_________________________________________________ ________

This would be a good way to go in the sense of not requiring a
calibrated dial, but a GDO is necessarily a broadly tuned device simply
because a single tank circuit is a broadly tuned device. A high degree
of precision is neither needed nor even possible.

....because frequency it is pulled when dip occurs and when you adjust
excitation for best reading on the meter

Still, I like the concept.

--
Bill, W6WRT


73
LA8AK
--
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In article , Wes Stewart
writes:

On Sun, 16 Nov 2003 05:09:01 -0800, Bill Turner
wrote:

|On Sat, 15 Nov 2003 23:08:53 -0700, Wes Stewart wrote:
|snip
|The only problem was keeping the GDO hidden from the metrology guys
|since they couldn't "calibrate" and service them so they wanted them
|gone.
|
|________________________________________________ _________
|
|Great story, Wes. But why couldn't the metrology guys figure out a cal
|procedure? I suspect the Not Invented Here syndrome, right?


The worst thing that could happen to our equipment was for it to go to
"Calibration." I had more than one piece of equipment "accidentally"
dropped and broken when they tired of maintaining it. If they did
this to an HP/Boonton 250 Rx meter what do you think would happen to a
Model 59?

The best we could do was get an "inactive" sticker put on the
equipment. This took it out of the cal cycle but theoretically meant
that we couldn't use it for anything. Also there were the everpresent
management directives to get rid of inactive equipment to reduce
inventory costs. Imagine how much expense could be written off if
Hughes Aircraft Co (now Raytheon) got rid of a Model 59 GDO g.

Dunno why you guys want to pick on metrology departments.

It's up to CORPORATE to see that metrology departments do
their thing properly. Most of them do. I worked in one for a bit over
two years (Ramo-Wooldrige) and everything was done according to
factory information and procedures. RCA Corporation was done the
same way.

On the other hand, Electro-Optical Systems (a Xerox division) was
terribly lax that way and any department could tag something out of
service and have it stored. EOS Corporate put such loose controls
on it that anyone could go into the storage area and "requisition"
anything, no questions asked.

Len Anderson
retired (from regular hours) electronic engineer person

In article , Wes Stewart
writes:

On Sun, 16 Nov 2003 05:09:01 -0800, Bill Turner
wrote:

|On Sat, 15 Nov 2003 23:08:53 -0700, Wes Stewart wrote:
|snip
|The only problem was keeping the GDO hidden from the metrology guys
|since they couldn't "calibrate" and service them so they wanted them
|gone.
|
|________________________________________________ _________
|
|Great story, Wes. But why couldn't the metrology guys figure out a cal
|procedure? I suspect the Not Invented Here syndrome, right?


The worst thing that could happen to our equipment was for it to go to
"Calibration." I had more than one piece of equipment "accidentally"
dropped and broken when they tired of maintaining it. If they did
this to an HP/Boonton 250 Rx meter what do you think would happen to a
Model 59?

The best we could do was get an "inactive" sticker put on the
equipment. This took it out of the cal cycle but theoretically meant
that we couldn't use it for anything. Also there were the everpresent
management directives to get rid of inactive equipment to reduce
inventory costs. Imagine how much expense could be written off if
Hughes Aircraft Co (now Raytheon) got rid of a Model 59 GDO g.

Dunno why you guys want to pick on metrology departments.

It's up to CORPORATE to see that metrology departments do
their thing properly. Most of them do. I worked in one for a bit over
two years (Ramo-Wooldrige) and everything was done according to
factory information and procedures. RCA Corporation was done the
same way.

On the other hand, Electro-Optical Systems (a Xerox division) was
terribly lax that way and any department could tag something out of
service and have it stored. EOS Corporate put such loose controls
on it that anyone could go into the storage area and "requisition"
anything, no questions asked.

Len Anderson
retired (from regular hours) electronic engineer person

hi

This gdo uses three fet and runs off two aa batteries, nice project.
The coils are built with bnc connectors.

jimbo


Michael wrote:

james ) writes:
Hi Paul,

ARRL QST had nice article on a modern GDO

May 2003 QST page 54 A Modern GDO--The "Gate" Dip Oscillator Bloom, Alan, N1AL


73 jimbo

Paul wrote:

But is it really modern, or just a rehash of what's come before?

I haven't seen the article, but in thirty years of reading the magazines
(and I've seen plenty of back issues from before that), there has been
very little change. Most of the articles are a small variant on a previous
article, with any real change being about coil forms ("I didn't have what
the previous article used", or "I noticed these things that would make a GDO,
so I built one around them") or variable capacitor.

Admittedly, when solid state devices came along, there had to be some change
since people did want to make use of them. The original ones were likely
pretty bad, using bipolar transistors, and of course there was the Tunnel
diode one from Heathkit. Once FETs came along, the GDOs were back to
basically a tube circuit, albeit with low supply voltage.

There have been the occasional outrageous scheme, switchable coils,
or making use of an existing signal generator or building a whole GDO along
such lines, but they never really held. Next time a GDO article was
published, it was back to simplicity.

If I was building one, I'd make sure it had a good reduction drive. I'd
certainly put in a buffer for an output, as a signal generator or to feed
a frequency counter. The latter then means the dial doesn't require much
effort, and the readout will be much much better than any GDO from before.
Maybe I'd even build a plug-in that has switchable coils, but the whole
thing is shielded, for those times when you just wanted a signal generator.

But I'd also be looking at the circuitry of the Millen Solid-state GDO,
from the early seventies. It was a more extensive design, but of course
it costs virtually nothing for those extra active devices. They found they
had to put a variety of chokes in the thing to isolate the oscillator from
the B+ line, so there weren't false dips.

The Heathkit from the eighties seemed rather interesting. Again, it
was a more complicated design. I can't remember what the extra circuitry
amounted to. That design did generate some similar home made circuits
at the time.

Michael VE2BVW

hi

This gdo uses three fet and runs off two aa batteries, nice project.
The coils are built with bnc connectors.

jimbo


Michael wrote:

james ) writes:
Hi Paul,

ARRL QST had nice article on a modern GDO

May 2003 QST page 54 A Modern GDO--The "Gate" Dip Oscillator Bloom, Alan, N1AL


73 jimbo

Paul wrote:

But is it really modern, or just a rehash of what's come before?

I haven't seen the article, but in thirty years of reading the magazines
(and I've seen plenty of back issues from before that), there has been
very little change. Most of the articles are a small variant on a previous
article, with any real change being about coil forms ("I didn't have what
the previous article used", or "I noticed these things that would make a GDO,
so I built one around them") or variable capacitor.

Admittedly, when solid state devices came along, there had to be some change
since people did want to make use of them. The original ones were likely
pretty bad, using bipolar transistors, and of course there was the Tunnel
diode one from Heathkit. Once FETs came along, the GDOs were back to
basically a tube circuit, albeit with low supply voltage.

There have been the occasional outrageous scheme, switchable coils,
or making use of an existing signal generator or building a whole GDO along
such lines, but they never really held. Next time a GDO article was
published, it was back to simplicity.

If I was building one, I'd make sure it had a good reduction drive. I'd
certainly put in a buffer for an output, as a signal generator or to feed
a frequency counter. The latter then means the dial doesn't require much
effort, and the readout will be much much better than any GDO from before.
Maybe I'd even build a plug-in that has switchable coils, but the whole
thing is shielded, for those times when you just wanted a signal generator.

But I'd also be looking at the circuitry of the Millen Solid-state GDO,
from the early seventies. It was a more extensive design, but of course
it costs virtually nothing for those extra active devices. They found they
had to put a variety of chokes in the thing to isolate the oscillator from
the B+ line, so there weren't false dips.

The Heathkit from the eighties seemed rather interesting. Again, it
was a more complicated design. I can't remember what the extra circuitry
amounted to. That design did generate some similar home made circuits
at the time.

Michael VE2BVW

On Sun, 16 Nov 2003 22:33:38 GMT, (J M Noeding)
wrote:


sorry I don't really see your point. I bought my Tradipper in 67, and
it has been very useful since then, I may not use it so often now
because I've also got a Philips GM3121.
Mine operatet satisfactorily - as original - up to 140MHz, but the 2M
coil is no coil at all, only a short between to pins on the connector.

Maybe you have a different model. Mine purports to cover up to 360Mhz,
but there is *no way* AFAICS that the thing would be capable of
anything remotely close to that upper range limit, on cursory
inspection of the internals. I'm glad I went for the wholesale
re-build but still find it hopelessly impractical to use on minature,
in-circuit components.
--

"I expect history will be kind to me, since I intend to write it."
- Winston Churchill