开云体育

As my Tek 130 has lost its NEMA 5-15 inlet, and been butchered to use an IEC inlet.

I'm tidying up the rear panel and adding a small anodised plate to cover theunsightly square-peg-in-round-hole issue, but/and I have the option to either:
(a) Use an integrated IEC filter (e.g. a 1A Schaffner), or,
(b) Add some basic XY filtering across a non-filtered IEC, or,
(c) Add a chassis mount power filter.

(a) is neatest but needs further minor chassis butchering, (b) very easy, and (c) doable but less original.

Before I consume any cycles investigating, do people here think I need to consider adding filtering to this particular instrument?

The130 uses two low frequency oscillators, 100..150 kHz. No modern line filter works below the FCC, or other minimum frequency.

The instrument is not affected by incoming EMI nor creates conducted EMI.

I would forget the filter and just install a plain IEC recepticle

Jon

Super, thanks Jon.

I agree - no line filter is needed. I'd say also that no extra trim plate is needed either unless the metalwork has been messed up. I changed my 130s to IEC recently by filing out the hole periphery with a 3/8" D or so round file just enough clear the chamfer and rounded corner features of the IEC connector. The original hole shows a bit, but I don't mind since it's on the back. Here's what it looks like:

/g/TekScopes/photo/296248/3803157?p=Created%2C%2C%2C20%2C2%2C0%2C0

Ed

Richard, many thanks glad I could help.

Ed, fine mod, I will do the same on my 130 LC. By the way are the meter scales hand calibrated?

Plan à similaire mod for à Tek 191 constant amplitude generator ( 50 kHz..100 Mhz).

Remarkable these 1960s units are still working, mine are in cal.

Jon

I have to redraw the scale for mine, it's faded beyond readability. If those scales weren't individual to the meter the redrawn scale might be of some use to others.

Not happening anytime soon though, still moving and setting up.

Bill in BC, Canada

There are several software programs for generating meter faces, paid or free. Two are:


<>



Googling for meter design software will find other approaches or comments and comparisons.

John??? KK6IL

Thanks for that and filed away. Here's a link to one I did 30 years ago in Freehand on Mac a running OS 9.2.2, Did the arithmetic and just drew it, in about half a day:



Here's the front panel layout for a Quan-Tech Spot Noise meter



which I've been working on because the stock, linear-reading meters have about 10Db of range and the thing is an endlessly-range-switching pita to run.

In addition to making it log reading, I want to change the spot noise meter itself from a 10Hz-to-100KHz machine to a 3Hz-to-30KHz machine because I do tube audio and want to get a better look at 1/f as tubes tend to run to a 1/f-ish noise spectrum.

Bill in BC, Canada

There are several software programs for generating meter faces, paid or
free. Two are:

This link is now correct:

Googling for meter design software will find other approaches or
comments and comparisons.
John??? KK6IL

Wow - I had spotted my scale is non-linear but had not appreciated that they were individual to the meter.

When you say 'meter' do you mean one scale for that particular range of meters as used in that piece of equipment, or do you mean individual to each meter and/or each piece of equipment?

I too need to re-do mine - the red has almost gone.

When I started working on mine, I found that bits of the meter scale were flaking off; so, I made an accurate photo of it. (I have a fairly good digital macrophotography setup). If the scale gets bad enough to need replacement, I'll edit out the bad parts of the photo
with gimp or photoshop (for Windows users), and print out a new high quality scale with a photo printer.

Over the years I have heard that the meter scales on certain HP gear were custom ruled as part of initial calibration, so specific to the individual instrument, but I have no idea of which ones are this way. I don't know if any Tek ones are, but I doubt it. If anyone gets to a point where they need to take a meter apart for repair, it's a good idea to take an accurate picture or flatbed scan of the face just in case, for future reference and use.

Ed