Can you post a picture of what you are seeing?

Vladan

Hello,
the 3MHz filter shows the strange characteristic of a critically couple bandpass filter instead of the usual shape. Adjusting coils L2, L4 and R1 gives no improvement. The mica caps in this filter sh?uld be rock stable?! Before I desolder all components for measurement: does anyone have come across this problem before and can give me a hint.

Regards
Ernst

--

Ah, so *that's* how the +20dBm level is reached. I now see the moving cursor. I thought it was just a scratch on the panel! Thanks, Frank.

So that just leaves my question about the setup needed for receiver IMD measurements.

Best wishes, Alan G3XAQ

Hello,

On Thu, Oct 22, 2015 at 12:30 PM, Alan Ibbetson alan@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

I'm new to this group. I've diligently searched the archives but can
find no mention of early 8640B models seemingly intended to produce
+10dBm maximum output instead of the more usual +20dBm.

I have a pair of these 8640B signal generators, the early-model one
having been recently purchased so I can make IMD measurements on my
homebrew ham radio receivers. The other one I've had for some years has
the common fault with broken plastic gears and Paul K is helping me out
with this, hence in the meantime me putting the later purchase into
service and being "surprised" at the lower output.

The serial number is 1434U00265, so it's a 1974 model. The output range
switch has a scale marking at -140dBm and also one at +20dBm, but the
switch does not rotate beyond +10dBm. Does anyone know when HP increased
the power output? Does it mean this example doesn't contain the dreaded
monolithic output amplifier? Although the range/deviation switches use
proper wafers instead of microscopic spring fingers on plastic discs the
mechanically mad plastic gears are there so I suspect there will be
service work to do in the future.

I have both models, the output level range is basicly the same on
both, but the one with the amplitude dial with the -140 dBm mark can
go to +20 dBm too using the fine level knob. You'll notice that the
level full scale will change as you move the fine level knob and a
small mark under the large dBm marks moves to indicate the actual
output power.

HTH
Frank IZ8DWF

I'm new to this group. I've diligently searched the archives but can find no mention of early 8640B models seemingly intended to produce +10dBm maximum output instead of the more usual +20dBm.

I have a pair of these 8640B signal generators, the early-model one having been recently purchased so I can make IMD measurements on my homebrew ham radio receivers. The other one I've had for some years has the common fault with broken plastic gears and Paul K is helping me out with this, hence in the meantime me putting the later purchase into service and being "surprised" at the lower output.

The serial number is 1434U00265, so it's a 1974 model. The output range switch has a scale marking at -140dBm and also one at +20dBm, but the switch does not rotate beyond +10dBm. Does anyone know when HP increased the power output? Does it mean this example doesn't contain the dreaded monolithic output amplifier? Although the range/deviation switches use proper wafers instead of microscopic spring fingers on plastic discs the mechanically mad plastic gears are there so I suspect there will be service work to do in the future.

Is it OK to ask applications questions on here? I'm wondering how much reverse isolation I need between my pair of generators to make accurate IMD measurements? I'll be looking for spurs at the noise floor of the receiver, say -130dBm or lower, and for a decent receiver this will need -30dBm signals from each generator. I'm thinking about, say, a 10dB pad between my hybrid combiner and receiver, with maybe a 20dB pad between each generator and the hybrid. Is this enough to ensure there will be no IMD from the generators caused by the crosstalk between them? Or do I need to think about external amplifiers and yet more attenuators?

Thanks,

Alan G3XAQ

Hi all,

Given the choice, would you rather pick an E4407B that is pretty optioned up, or a basic E4445A?

I don't need any of the personalities the ESA has and so the only attractive points are the narrow RBW and dynamic range expansion. I also don't really need the 26GHz BE, half is enough. Also, the Ethernet port on the PSA makes it easier for me to get data out of the device.

I used to have an E4406A and from what I hear the gui and use is very similar to the ESA.

I recently acquired an E8357A PNA, which is why I tend towards the PSA but I woul very much like to hear orher's opinions.

Thanks,
Chris

Looking for rack mount kits for some of my HP gear, 5316, 53132A, 33401A, 437B, and similar sized gear.

Google doesn't find anything for 5060-0174.

Any suggestions?

bob k6rtm

On 10/21/2015 05:55 PM, w1ksz@... [hp_agilent_equipment] wrote:

I have three HP Power Meters (435B, 436A & 438A), three sensors (8482A,
8482H & 8484A)
along with three sensor cables (11730B).

One of the Sensor Cables has one of the pins removed such that is now a
7 pin Cable.
I was wondering why one of the pins would be removed ?

I cannot locate a pin-out diagram of the connector so cannot tell which
function it once
served (If anyone has a diagram of the connector pin-out. I would
appreciate it.

TIA for any help solving this,

Hi Dick, FYI the pinouts of these connectors are in the service
manuals of several of the power meter models.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

I have three HP Power Meters (435B, 436A & 438A), three sensors (8482A, 8482H & 8484A)
along with three sensor cables (11730B).

One of the Sensor Cables has one of the pins removed such that is now a 7 pin Cable.
I was wondering why one of the pins would be removed ?

I cannot locate a pin-out diagram of the connector so cannot tell which function it once
served (If anyone has a diagram of the connector pin-out. I would appreciate it.

TIA for any help solving this,

Dick, W1KSZ

I would have spent the 400-600 dollars for a calibrated 437 and power sensor if I had not got mine much cheaper. The point……………i thought the same thing, but then realized that this is one of those times when simply paying the piper is the way to go. It is a VERY rare occasion that this is true for me, but here it is almost fact.

Cheers,

David

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Has anyone had any experience repairing an 8481A power sensor? Functional ones look to be quite expensive but "needs repair" items are much more reasonable.

Dale

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Greetings,

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?

Hi Dan and George,

I have a non-working 215A on my desk and besides of lacking enough old oval connector power cords I am in need of a manual.

So if you already have a scanned manual I would be glad to receive a copy of it.

Any help would be appreciated, even schematics only would help.

Thanks and regards,

Rudi

-- 
Dave
Manuals@...

HI My hp182c has a High voltage fault , The inverter transformer primary shows very Low resistace and the seconaries are Open circuit it will not oscillate

Can I get a high voltage inverter transformer antwhere ?


Dave? GM3WIL

Hi Dan and George,

Hi Dave,
I'll bring my box of spares down on Saturday. You can pick? colour you like :-).

Robert G8RPI.
P.S. Just remembered I owe you some paperwork, I'll get on it.

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