Date   

Re: OT 10Mhz references

mosaicmerc
 

After doing research on the issue, it appears that the economical approach was a Trimble 65256 OCXO ($16) as it is well respected, has low phase noise, is sine wave and is SC cut.
Morion 89A was a close second. The Epson Toyocom TCO- 6920, while interesting, I can't find any data on it and it's signal was under 0 dBm.


As a low risk approach I ordered a $16 Trimble OcXO, 12V, 10Mhz Sine, o - 7dBm output unit that didn't look banged up and the current draw isn't unreasonable.
Once all is well I'll make a low noise linear PSU and an isolated 50 ohm distribution amp and feed the various instruments.
As a useful spin off, I'll do a divide by 2 reference for my DC505A counter to replace its tank circuit. I believe it's a 5MHz ref.


Re: 7854 Repair & Restoration

 

On 10 Mar 2016 23:49:17 -0800, you wrote:

I'm pretty sure that these canned hybrids are always plugged into Berg sockets that sit nearly flush with the board surface. These are among the most reliable IC pin connector types I know of, despite their low profile and simplicity. I've never seen a bad one except where abused by the wrong lead diameter or chemical attack.
I have always been suspicious of the mini-Berg sockets and have run
into a couple cases where good contact was not being made. I think
the machined collet pins which you mention below are more reliable.

The pins on the solder side of the board are fat, indicating they are likely Berg sockets. Tomorrow I'll see if I can pull the hybrids out of one of the spare amplifier boards. This should also tell whether or not there's thermal grease underneath.

There are at least two types of low profile socket pins - the Bergs that I often refer to are made from tiny drawn and crimped sheet metal components, and are usually pressed into the board early in the build process. They often have a white silicone elastomer glob seal on the opening, which is punctured by the part lead when installed. Tek often used these for transistor and IC pins, and also as the center conductor receptacle for board-mounted Peltola connectors.

The other kind are high quality machined sockets, originated by Augat, I think, and commonly used in very good IC sockets and low profile in-board pins and strips. I think HP used a lot of these.

Ed
I cut those out of sockets and SIPs to use them as low profile collet
pins for ICs, transistors, and any other leaded part I might want to
replace later.

http://www.mouser.com/Search/ProductDetail.aspx?R=310-93-164-41-001000virtualkey57510000virtualkey575-193164

On 11 Mar 2016 12:01:09 -0800, you wrote:

I looked at that vertical amp board again and found that the cans are plugged into Berg sockets, and there is thermal grease underneath for better cooling. Also, I hadn't noticed before that two of the pins on the bigger output amplifier are much longer, and were passed though unplated, un-socketed holes, for connection to the deflection plates. There's no solder on them either, and I can't remember if I clipped them off from other leads (very unlikely), or if they were plugged into loose Berg sockets attached to the CRT lead wiring.
What color was the thermal grease? I assume it was white indicating
zinc oxide?

I never removed one of the hybrids from its board.

If the 7854 hookup is made that way, that's another possible location for intermittent connections.
I had my 7834 vertical amplifier board removed several times when I
was messing with the CRT to try and fix its geometry problem. The
first time I did not realize that the leads from the output hybrid to
the deflection plate pins had collet socket pins on the CRT side and I
unsoldered the wires from the collet socket pins leaving the collets
pins in place. The wires were soldered to the thick leads from the
output hybrid.

I must have taken the vertical amplifier board off of my 7854 to
replace R160 but the only thing I remember about it is the lesson from
my 7834; I pulled the collets straight off of the CRT leads instead of
unsoldering the wires. I think the wires were soldered directly the
thick leads from the output hybrid. (I just verified this with visual
inspection.)

On 11 Mar 2016 16:49:17 -0800, you wrote:

Thank you for looking into the TO-8 amplifier arrangement for me, Ed & David. Now I know exactly what to expect.

From your descriptions, I feel the best way to go about pinpointing and solving the issue is going to be to pull the board, carefully pull the U50 driver, inspect, clean off the old paste and the leads with IPA, inspect again, reapply thermal paste, then gently re-insert the amp into the sockets. I might as well do the same for U150 while the board is off.

First and foremost, I am going to put magnification to the board and check all the solder joints of surrounding components and reflow any suspect ones.

Also, only U50 on mine has the plastic clamp.
I checked and all of mine, 7904, 7834, and 7854, are built the same
way. They have the plastic clamp and ground connection on U50,
insulated leads on the output hybrid soldered to wires, and a stud on
the output hybrid bolted to the aluminum bracket under the board.

Hopefully this solves the problem. I did 'spudge' the potentiometers and resistors on the board, but only tapping or pressing on U50 induced the fault. I don't think this alone can rule out the possibility of a faulty component in the driver or amps surroundings. Ensuring all of the connections are positive is definitely the #1 step.

The only major question I have here is about thermal paste.... all I have on hand is Arctic Silver from RS. It's the higher end stuff that they carry. Do you think that will be sufficient? Should I find a resource for a Tek recommended thermal compound - or try to salvage the 25-35yr old stuff that's already there?
Don't reuse the old thermal paste. Tektronix probably used a standard
silicon oil and zinc oxide thermal paste like Wakefield 120. It is
not critical so use anything you happen to already have as long as it
is not electrically conductive.


Re: Tektronic 466 - Storage Modes inop

Jim McIntyre
 

First off, please forgive my mis-spelling in the title...

It was a typo, honest, I know how to spell Tektronix...


So, I've found a interesting hint. The 1.4V supply, which I guess is supposed to be regulated to 1.4V by Q2092/Q2094 is sitting at -1.8V all the time - even through an erase cycle. What I haven't figured out yet is what is supposed to source current into the 1.4V rail, as Q2094 appears to be a shunt regulator of sorts...


Re: OT 10Mhz references

J. L. Trantham
 

I guess it's a question of what you mean by 'precision'. If you are happy
using WWV as your 'reference' and 'zero-beating' your 'house standard'
against that, then you don't need anything else. However, if you want
something that is 'always right', a GPSDO is hard to beat.



It's also reasonably affordable.



I've had GPSDO's 'die'. Therefore, having the ability to turn it on and
have it up and accurate in 20 or 30 minutes or so is very nice. Having a
separate 'house standard' that you, from time to time, 'adjust' to bring
back 'on frequency' and is more easily replaced is, in my opinion, a good
combination.



Now, if you want to dig deeper into the performance/math of the systems, you
can spend a lifetime (or remaining lifetime, in my case) doing that. It is
quite satisfying if you can spare the time to do it. No pun intended.



Joe



From: TekScopes@yahoogroups.com [mailto:TekScopes@yahoogroups.com]
Sent: Friday, March 11, 2016 12:23 PM
To: TekScopes@yahoogroups.com
Subject: Re: [TekScopes] Re: OT 10Mhz references





I am curious what you guys are doing that requires that sort of
long-term precision?

On 11/03/2016 8:44 AM, 'J. L. Trantham' jltran@att.net [TekScopes] wrote:

You can get a 'stand-alone' 10 MHz 'reference' such as an HP 10811 or
any of
the oscillators you and others have mentioned and could be left on
permanently. However, you will eventually need a 'primary standard'
(Cesium, GPS disciplined oscillator, etc.) for comparison to be able to
'adjust' it back on frequency as time goes by.


Re: Blue Filter P/Ns for 24xx Scopes

n4buq
 

Yes, Håkan. Exactly what I was looking for.

Thanks!
Barry - N4BUQ

----- Original Message -----
From: "hahi@telia.com [TekScopes]" <TekScopes@yahoogroups.com>
To: TekScopes@yahoogroups.com
Sent: Friday, March 11, 2016 5:25:22 PM
Subject: Re: [TekScopes] Blue Filter P/Ns for 24xx Scopes

There is general confusion regarding the part number for these filters.
There were four types of CRT filters for 2400's.

378-0199-00 replaced by 378-0199-03
378-0199-01 replaced by 378-0199-04
378-0199-02 replaced by 378-0199-05
The initial three (-00 thru -02) were made of polycarbonate and the
replacements were made
of acrylyc which made them more scratch resistant and they could be cleaned
using
pure alcohol. They were all blue but only the first ones (-00/-03) are for
standard instruments
while the others (-01/-04 & -02/-05) are for OPT 05 (TV Trigger) instruments.
I don't know for
sure but a qualified guess is that they have a Video graticule possibly NTSC
and PAL.

378-0208-00, clear made of polycarbonate, no replacement

Hope this cleared some of the confusion.

/Håkan

[Non-text portions of this message have been removed]


Re: OT 10Mhz references

Torch
 

For some reason, I can't seem to open the file on your hard drive ;-)

I suppose I can see the need for ultimate precision and stability for those of you set on proving Einstein right about the effect of gravity on time. But for us plebeians who are still living in a world populated with 100 or 200MHz scopes, it might be overkill. ;-)

On 11/03/2016 1:45 PM, 'Craig Sawyers' c.sawyers@tech-enterprise.com [TekScopes] wrote:

Rakon have taken this up though file:///F:/Downloads/USO%20HSO14%20Shortform-A1.pdf , but a BVA
crystal oscillator will set you back 10k somethings (dollars, euros, UKP).


Re: 7854 RAM card upgrade only - any interest?

 

On 11 Mar 2016 13:20:45 -0800, you wrote:

The dongle approach would add the cost of two connectors and a housing, Also all of the cable wires would have to be connected through (another circuit board or a wire and soldering iron session).
I was thinking that the dongle could be used instead of the external
keyboard.

The snap off printed board adds to the area ($) and would have to be the full height of the memory board, I guess, which is too big and it would have to snap in two to discard the excess area.
It would probably not be worth the extra cost given the simplicity of
the circuit. See below.

I tried to open my keyboard and ran into a problem with one screw that is so badly jammed that I may have to drill it out and replace it. Maybe inside the keyboard is not so easy after all.
I had the same problem with the keyboard and used a small socket
wrench with a T10 Torx bit to force the screws out. If it does not
turn, force it. If it breaks, it was defective anyway.

All of these seem like overkill to install just three components. If buyers will be doing all of their own mounting and soldering of sockets and components on the memory card, a tiny piece of perfboard with copper around the holes is a very common prototyping item for less than a dollar. We could just add that to the kit with instructions. All options will require some soldering somewhere, so no one solution has the advantage there, unless we provide a fully preassembled dongle based version at considerable extra cost.
I tested the single transistor open collector inverter wired onto a D
connector and it worked fine. The 7854 booted up in memory backup
mode instead of memory test mode when the dongle was attached to the D
connector in place of the external keyboard. I will make some
measurements of the signal voltages to verify good noise margin.
Adding a base-emitter shunt resistor might be necessary.

I had not really taken notice before but in self test mode, the 7854
beeps and displays the self test message. In memory backup mode, the
7854 displays the self test message without beeping.

Also in memory backup mode not only is the state of the vertical and
horizontal mode switches maintained, but so is the CRT mode of scope,
stored, or both. Tektronix thought of everything. I wonder if any
state *isn't* retained.

The rear A32 area may be the easiest to access after all.There is room in there to stick on a small pefboard using double faced foam tape, or the board might be soldered directly on the terminals of the new switch. Getting the three ribbon cables correctly replugged to A32 does take good light and a bit of dexterity.

Cliff
I would air wire it to the existing A32 rear panel connector board.


Re: 7A13 Knob

Brian Bloom
 

Does this happen to be the knobby you seek?
>>
>Unfortunately, it isn't.

>The correct knob does not have the black insert at the front. Instead, there's empty space in that area to >allow the pull-out variable attenuation button with its white ring to "sink in" at least 5 mm, probably more like >7-8 mm.

>The knob on Ebay looks like what's used on e.g. the 1481 Waveform Monitor's front, at the right side.

>Raymond

Well that's a bummer.

I wonder if it's just a variation of the same knob, or if there is some other difference such as the shaft diameter..
If the only difference is the black plastic insert... well..
If I was the person needing that knob, I would buy this one and cut the black insert out.
The only problem is that I would have to physically have the knob in order to make sure that it'll fit the 7A13 in the first place.

Maybe the seller wouldn't mind breaking out a caliper and taking some measurements, though...?

*Actually, this knob appears to be the very same knob that is used on the 454 for V/div control. If it is, I have ones on my 454A that I could measure so we'll know if it's the same apart from the insert*


Making ones own replacement knobs may well end up being a very useful project for many people, though. Tek replacement knobs are bound to disappear at some point.

A database of replacement knobs would be useful... then part B of that database project could be adding 3D scans of good knobs so people can print off or machine replacements.

-Brian


Re: 7854 Repair & Restoration

Brian Bloom
 

Thank you for looking into the TO-8 amplifier arrangement for me, Ed & David. Now I know exactly what to expect.

From your descriptions, I feel the best way to go about pinpointing and solving the issue is going to be to pull the board, carefully pull the U50 driver, inspect, clean off the old paste and the leads with IPA, inspect again, reapply thermal paste, then gently re-insert the amp into the sockets. I might as well do the same for U150 while the board is off.

First and foremost, I am going to put magnification to the board and check all the solder joints of surrounding components and reflow any suspect ones.

Also, only U50 on mine has the plastic clamp.

Hopefully this solves the problem. I did 'spudge' the potentiometers and resistors on the board, but only tapping or pressing on U50 induced the fault. I don't think this alone can rule out the possibility of a faulty component in the driver or amps surroundings. Ensuring all of the connections are positive is definitely the #1 step.

The only major question I have here is about thermal paste.... all I have on hand is Arctic Silver from RS. It's the higher end stuff that they carry. Do you think that will be sufficient? Should I find a resource for a Tek recommended thermal compound - or try to salvage the 25-35yr old stuff that's already there?


Re: Blue Filter P/Ns for 24xx Scopes

 

There is general confusion regarding the part number for these filters.
There were four types of CRT filters for 2400's.

378-0199-00 replaced by 378-0199-03
378-0199-01 replaced by 378-0199-04
378-0199-02 replaced by 378-0199-05
The initial three (-00 thru -02) were made of polycarbonate and the replacements were made
of acrylyc which made them more scratch resistant and they could be cleaned using
pure alcohol. They were all blue but only the first ones (-00/-03) are for standard instruments
while the others (-01/-04 & -02/-05) are for OPT 05 (TV Trigger) instruments. I don't know for
sure but a qualified guess is that they have a Video graticule possibly NTSC and PAL.

378-0208-00, clear made of polycarbonate, no replacement

Hope this cleared some of the confusion.

/Håkan


Re: 2465A focus

chipbee40
 

Hi Chris,
Thanks for the response, turned out to be a duff tube, what a pita that is to swap to test!
Initially though the focus at end stop was caused by misadjustment of the edge focus internally.



---In TekScopes@yahoogroups.com, <chris@...> wrote :

I've got four 24xx scopes, and on three of them the optimum focus point is
roughly in the middle of the focus knob's travel. One one of them (a 2465)
the best focus is with the focus knob turned all the way counter-clockwise.
In that position the display is as sharp as the other scopes, so I've never
looked in to why it is the way it is, but something odd must be going on.

This probably isn't a lot of help to you but it shows that oddness with the
focus control is not unknown.

Chris

On Fri, Mar 11, 2016 at 1:40 AM, chipbee40@... mailto:chipbee40@... [TekScopes] <
TekScopes@yahoogroups.com mailto:TekScopes@yahoogroups.com> wrote:

>
>
> Hi, All you 24xx experts.
> Just had a customer bring a 2465A in. Has a 2016 expiry cal cert from a
> reputable source. Customer complaint is poor focus. Sure was. Focus at end
> stop. I'm limited to what I can adjust because it may get returned but
> opening it up edge focus was also at end stop. (customer twiddling?) Power
> supply ripple and volts all good, well within spec, very clean scope, How
> can you check hours use on this?.
> So I did the focus and astig adjustments and got a reasonable display but
> I'm not convinced this is the best a 300Mhz scope can do.
> So how good is this scope display supposed to be? I don't get many 24xx
> scopes, the last 2445 was a couple of years back and it didn't stand out as
> particularly blurry. I must admit I'm comparing to my Fluke PM3394B which
> is ultra sharp but this is on par with a 2230 or slightly worse. Text and
> traces are not as sharp as I would expect, not out of focus but just not
> sharp. Also I seem to have to continually correct the focus depending on
> signal or display option. doesn't seem right to me.
> I checked the resistors in the focus circuit, all bang on.
>
> Do the tubes soften on these? Anything I should check before I tell the
> guy this is as good as he can expect?
> TIA.
>
>
>
>
>


Re: 7854 RAM card upgrade only - any interest?

Cliff Carrie
 

The dongle approach would add the cost of two connectors and a housing, Also all of the cable wires would have to be connected through (another circuit board or a wire and soldering iron session).

The snap off printed board adds to the area ($) and would have to be the full height of the memory board, I guess, which is too big and it would have to snap in two to discard the excess area.


I tried to open my keyboard and ran into a problem with one screw that is so badly jammed that I may have to drill it out and replace it. Maybe inside the keyboard is not so easy after all.


All of these seem like overkill to install just three components. If buyers will be doing all of their own mounting and soldering of sockets and components on the memory card, a tiny piece of perfboard with copper around the holes is a very common prototyping item for less than a dollar. We could just add that to the kit with instructions. All options will require some soldering somewhere, so no one solution has the advantage there, unless we provide a fully preassembled dongle based version at considerable extra cost.


The rear A32 area may be the easiest to access after all.There is room in there to stick on a small pefboard using double faced foam tape, or the board might be soldered directly on the terminals of the new switch. Getting the three ribbon cables correctly replugged to A32 does take good light and a bit of dexterity.


Cliff


Re: Blue Filter P/Ns for 24xx Scopes

 

There is general confusion regarding the part number for these filters.  Some sellers identify 378-0199-00 as being a clear filter and others identify it as being blue.  So I checked the Service Manuals.
The Service Manual for the 2465 calls out 378-0199-00 as a blue filter.The Service Manual for the 2465A calls out 378-0199-03 as a blue filter. The Service Manual for the 2465B calls out 378-0199-03 as a blue filter.  
My opinion is that either 378-0199-00 or 378-0199-03 will fit.  But double check the color because sellers, especially on eBay, have confused whether these are blue in color or clear.
From: "Barry n4buq@knology.net [TekScopes]" <TekScopes@yahoogroups.com>
To: TekScopes@yahoogroups.com
Sent: Friday, March 11, 2016 10:17 AM
Subject: [TekScopes] Blue Filter P/Ns for 24xx Scopes

  Does anyone know what the differences are for part number 378-0199-00 vs 378-0199-03? The manual I have shows -00 as the correct part number for a 2445 and am wondering if the -03 will also fit (as well as whether it's a plain blue without any markings, etc.). Is it possible these are identical but given new numbers for later models?

I know the -04 is a specially-marked filter but not sure about other suffixes.

Thanks,
Barry - N4BUQ
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Re: OT 10Mhz references

Brian Yee
 

Most instruments are not picky about whether the waveform is sine or
square, but make
sure it is properly terminated so the rising/falling edges are clean.

Brian


On Thu, Mar 10, 2016 at 11:55 PM, David davidwhess@gmail.com [TekScopes] <
TekScopes@yahoogroups.com> wrote:



The inputs on your instruments are not picky about waveshape. The
Rigols expect a signal level in the range of about 0dBm to 10dBm and
the HP VNA supports a much wider input range.

Your Rigol spectrum analyzer has a reference output which can be used
to feed another instrument. If you just want all three instruments to
be locked to the same reference, then this output could be fed to the
Rigol signal generator and the HP VNA.

On 10 Mar 2016 16:39:15 -0800, you wrote:

Hi all:
I'm hoping to ref. a Rigol DSA815, a Rigol DG1022A sig gen and an HP
8753D VNA....to a good 10Mhz ref.
I see a heap of them here:
http://stores.ebay.com/Flyingbests-Equipment/High-reliability-OCXO-/_i.html?_fsub=908870013&;_sid=282770553&_trksid=p4634.c0.m322

IDK what voltage is optimal or which unit to chose (*sine/square, single
or double OXCO) and need some advice on this.
tx


Re: 7854 Repair & Restoration

Ed Breya
 

I looked at that vertical amp board again and found that the cans are plugged into Berg sockets, and there is thermal grease underneath for better cooling. Also, I hadn't noticed before that two of the pins on the bigger output amplifier are much longer, and were passed though unplated, un-socketed holes, for connection to the deflection plates. There's no solder on them either, and I can't remember if I clipped them off from other leads (very unlikely), or if they were plugged into loose Berg sockets attached to the CRT lead wiring.

If the 7854 hookup is made that way, that's another possible location for intermittent connections.

I also found another different board, which I had marked as from a 7904 (670-1630-04), so the first one must have been from a 7844. The 7904 board has the same arrangement of a TO-8 driver in Berg sockets, with the plastic clamp, but the output amplifier is a stud-mount case instead, mounted to a small aluminum heatsink bracket under the board. Likewise, the pins are in Berg sockets, except for the output ones, which are soldered to small wire jumpers that went to the CRT.

Ed


Re: OT 10Mhz references

Dave Wise
 

An activity affectionately known as "time-nuttery".

Dave Wise

-----Original Message-----
From: TekScopes@yahoogroups.com [mailto:TekScopes@yahoogroups.com]
Sent: Friday, March 11, 2016 10:45 AM
To: TekScopes@yahoogroups.com
Subject: RE: [TekScopes] Re: OT 10Mhz references

I am curious what you guys are doing that requires that sort of long-term precision?
Because it is there, and affordable. There are those who are a whole lot worse in that regard. The
ultimate reference is a hydrogen maser - and there are guys out there who have one (have a look at
time nuts website) at many tens of thousands. Or if you want the ultimate in phase noise, a BVA
SC-cut ovenised crystal is almost unbeaten for this
http://www.oscilloquartz.com/files/1363164953-Br_%20OCXO%208607.pdf . Oscilloquartz were alas
acquired and discontinued their world beating expertise in this difficult corner of technology.

Rakon have taken this up though file:///F:/Downloads/USO%20HSO14%20Shortform-A1.pdf , but a BVA
crystal oscillator will set you back 10k somethings (dollars, euros, UKP). But although the phase
noise and Allen deviation are astoundingly good, the frequency will drift in common with all crystal
oscillators.

I'm happy though with my humble Trimble - a couple of hundred once you have the active bullet
antenna with a good view of the sky.




------------------------------------
Posted by: "Craig Sawyers" <c.sawyers@tech-enterprise.com>
------------------------------------


Re: OT 10Mhz references

Craig Sawyers <c.sawyers@...>
 

I am curious what you guys are doing that requires that sort of long-term precision?
Because it is there, and affordable. There are those who are a whole lot worse in that regard. The
ultimate reference is a hydrogen maser - and there are guys out there who have one (have a look at
time nuts website) at many tens of thousands. Or if you want the ultimate in phase noise, a BVA
SC-cut ovenised crystal is almost unbeaten for this
http://www.oscilloquartz.com/files/1363164953-Br_%20OCXO%208607.pdf . Oscilloquartz were alas
acquired and discontinued their world beating expertise in this difficult corner of technology.

Rakon have taken this up though file:///F:/Downloads/USO%20HSO14%20Shortform-A1.pdf , but a BVA
crystal oscillator will set you back 10k somethings (dollars, euros, UKP). But although the phase
noise and Allen deviation are astoundingly good, the frequency will drift in common with all crystal
oscillators.

I'm happy though with my humble Trimble - a couple of hundred once you have the active bullet
antenna with a good view of the sky.


Re: OT 10Mhz references

Torch
 

I am curious what you guys are doing that requires that sort of long-term precision?

On 11/03/2016 8:44 AM, 'J. L. Trantham' jltran@att.net [TekScopes] wrote:

You can get a 'stand-alone' 10 MHz 'reference' such as an HP 10811 or any of
the oscillators you and others have mentioned and could be left on
permanently. However, you will eventually need a 'primary standard'
(Cesium, GPS disciplined oscillator, etc.) for comparison to be able to
'adjust' it back on frequency as time goes by.


That calgary 7934 will be here for Stuff Day

 

Thanks to the efforts of more canadian Tek fans, the 7934 and all those 7S/7T plug-ins will be here in Kelowna (April 9th) for stuff day. In addition, Larry Correa said he can bring back items for those in the Washington/Oregon area with him. Many of you know him from his work at the Tek museum. If you organize it with Larry, there is a simple way to get your stuff down to the USA.

Anybody interested in any of the 7934 batch items, please email me off list, I will organize it for you. I will have time to run the plug-ins through the frame to check for general functionality, but nothing more than that. if this works for you, just let me know.

I will have a big batch of the 210 databook DVD's made up for stuff day, plus a time nuts list member has offered to stream it, so I will advise where you can grab the files shortly, once he has his DVD to work with. 4+Gb of excellent and hard to find semiconductor/tube manuals and app manuals and cross-references

Less than a month to go until stuff day + the amateur radio swap meet,
all the best,
walter & susan (walter2 -at- sphere.bc.ca)
http://www.sphere.bc.ca/test/


Blue Filter P/Ns for 24xx Scopes

n4buq
 

Does anyone know what the differences are for part number 378-0199-00 vs 378-0199-03? The manual I have shows -00 as the correct part number for a 2445 and am wondering if the -03 will also fit (as well as whether it's a plain blue without any markings, etc.). Is it possible these are identical but given new numbers for later models?

I know the -04 is a specially-marked filter but not sure about other suffixes.

Thanks,
Barry - N4BUQ

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