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Hi all,
I'm looking for a good HP detector, covering at a minimum 1MHz-500MHz, preferably BNC (SMA OK), negative output preferred, but positive OK.
Most importantly, not for an arm and a leg would be great. I get they can go for a pretty penny out there, but maybe there's an affordable one in this community to be had. Or a recommendation on where to look.?
Besides, I'd also appreciate input on just what HP part # I should be looking for, given my needs above.?
Thank you much in advance.
Radu.?
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Look for a HP 8471A
0.1 to 1200MHz and BNC
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Look at the HP 8471A
0.1 to 1200 MHz and BNC
/Hans
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Does it have to be HP?? For the frequency range that you are dealing with HP detectors seem to be a little overkill.? There are plenty of other manufacturers whose offerings would fit your needs at a much lower price especially if found on that auction site.? And many of them offer frequency ranges up to 10 GHz or more.
?
I have even found detectors installed on RF transmission line directional couplers from old broadcast transmitters that were heading for the scrap yard, were of major manufacture and swept out to 8 GHz.? The price was free.
?
Greg
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Hans - I've not been able to track down a datasheet or catalog page for the?
HP 8471A. The Keysight website is typically very good at having manuals, catalogs, datasheets, etc. for?vintage HP or Agilent equipment, but for this particular one - and it's the first?time I see a broken link on that website - points to catalog pages that are missing this component. The linked catalog goes to?
HP 8471D, E etc.?
Greg - it doesn't have to be HP; it's just I've been told the HP is the gold standard on detectors. Which seems to be reflected in price... But really all I need is good linearity. I have a couple of detectors currently - a vintage "Telonic" that doesn't seem to be worth anything, and a AD8307 active one that's pretty good but I still don't have a solid certainty of its linearity or even suitability. So, if another brand is known to be good (linear and reliable) but less glittery than HP and therefore can be had for less, I'd be interested in hearing about that.?
For instance, Wavetek has a detector which may fit the bill (D-152), but I haven't seen one for sale anywhere currently.?
Thank you, Radu.?
On Fri, Feb 4, 2022 at 8:44 AM Greg Muir via <big_sky_explorer= [email protected]> wrote: Does it have to be HP?? For the frequency range that you are dealing with HP detectors seem to be a little overkill.? There are plenty of other manufacturers whose offerings would fit your needs at a much lower price especially if found on that auction site.? And many of them offer frequency ranges up to 10 GHz or more.
?
I have even found detectors installed on RF transmission line directional couplers from old broadcast transmitters that were heading for the scrap yard, were of major manufacture and swept out to 8 GHz.? The price was free.
?
Greg
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See:
Might have a paper copy of the 8471A manual, which (if I can find it) will scan and make available
/Hans
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Just try eBay if you don't find one here.? While the prices of the *unsold* items on eBay are indeed crazy money, if you look at what has actually sold, it is much more reasonable.?? There are some HP 420A for $39 ... good to 12.4GHz
See:
Might have a paper copy of the 8471A manual, which (if I can find it) will scan and make available
/Hans
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Hans and Eric - thank you, that's very helpful. The Texscan (first time I heard about it) seems to have a very clean spec sheet, sounds like a very good deal for the money.
Robin - that one's pretty good price/spec ratio, but it doesn't seem to quite go as low as I need it (be flat to at least to 1MHz on the low end).?
Thank you all.
Just try eBay if you don't find one here.? While the prices of the *unsold* items on eBay are indeed crazy money, if you look at what has actually sold, it is much more reasonable.?? There are some HP 420A for $39 ... good to 12.4GHz
See:
Might have a paper copy of the 8471A manual, which (if I can find it) will scan and make available
/Hans
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A caveat: The guy said he wanted a 1 MHz to X Mhz detector: Most of the 423/420/Sage/FXR,MACOM etc Microwave detectors roll off (some pretty hard) below 10 MHz. This is due often to the DC return, RF Bypass Cap and the input coupling cap (if there is one). Low frequency coaxial detector design is different from microwave ones. I often build my own, just to show students how easy it is.
Jeff Kruth
In a message dated 2/4/2022 2:01:08 PM Eastern Standard Time, robin@... writes:
?
Just try eBay if you don't find one here.? While the prices of the *unsold* items on eBay are indeed crazy money, if you look at what has actually sold, it is much more reasonable.?? There are some HP 420A for $39 ... good to 12.4GHz
?
See:
Might have a paper copy of the 8471A manual, which (if I can find it) will scan and make available
/Hans
?
?
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That's true .. I don't really play in the areas below 100MHz, I forget the "low end" response ... but I guess for some people it is important.
A caveat: The guy said he wanted a 1 MHz to X Mhz detector: Most of the 423/420/Sage/FXR,MACOM etc Microwave detectors roll off (some pretty hard) below 10 MHz. This is due often to the DC return, RF Bypass Cap and the input coupling cap (if there is one). Low frequency coaxial detector design is different from microwave ones. I often build my own, just to show students how easy it is.
Jeff Kruth
In a message dated 2/4/2022 2:01:08 PM Eastern Standard Time, robin= [email protected] writes:
?
Just try eBay if you don't find one here.? While the prices of the *unsold* items on eBay are indeed crazy money, if you look at what has actually sold, it is much more reasonable.?? There are some HP 420A for $39 ... good to 12.4GHz
?
See:
Might have a paper copy of the 8471A manual, which (if I can find it) will scan and make available
/Hans
?
?
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Hi Strange the 1998 catalogue dues not have the 8471? and the 2000 catalogue only has the 8471D ? BUT the 1986 catalogue? held on this site the Catalogues section ?has the 8471A on pg 564 ? Paul B ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Radu Bogdan Dicher
Sent: 04 February 2022 17:39
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP detector ? Hans - I've not been able to track down a datasheet or catalog page for the? HP 8471A. The Keysight website is typically very good at having manuals, catalogs, datasheets, etc. for?vintage HP or Agilent equipment, but for this particular one - and it's the first?time I see a broken link on that website - points to catalog pages that are missing this component. The linked catalog goes to? HP 8471D, E etc.? Greg - it doesn't have to be HP; it's just I've been told the HP is the gold standard on detectors. Which seems to be reflected in price... But really all I need is good linearity. I have a couple of detectors currently - a vintage "Telonic" that doesn't seem to be worth anything, and a AD8307 active one that's pretty good but I still don't have a solid certainty of its linearity or even suitability. So, if another brand is known to be good (linear and reliable) but less glittery than HP and therefore can be had for less, I'd be interested in hearing about that.? For instance, Wavetek has a detector which may fit the bill (D-152), but I haven't seen one for sale anywhere currently.? ? On Fri, Feb 4, 2022 at 8:44 AM Greg Muir via <big_sky_explorer=[email protected]> wrote: Does it have to be HP?? For the frequency range that you are dealing with HP detectors seem to be a little overkill.? There are plenty of other manufacturers whose offerings would fit your needs at a much lower price especially if found on that auction site.? And many of them offer frequency ranges up to 10 GHz or more. ? I have even found detectors installed on RF transmission line directional couplers from old broadcast transmitters that were heading for the scrap yard, were of major manufacture and swept out to 8 GHz.? The price was free. ? Greg
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Hi Jeff,?
How about posting in files or here on how to build your own HF detector for HP432.?
Tnx? ? Joe? ?wa9cgz
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Hi Joe!
No can do: apples vs oranges 432 uses RF thermistors, not set up for diodes.
73
Jeff
In a message dated 2/4/2022 5:38:23 PM Eastern Standard Time, joeprice@... writes:
?
Hi Jeff,?
How about posting in files or here on how to build your own HF detector for HP432.?
Tnx? ? Joe? ?wa9cgz
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Jeff, "The guy" is asking whether you'd be willing to share directions for building a suitable detector for my initial request? :) In my book, DIY is the way, if possible. Thank you much in?advance.? Radu, aka "the guy."?
Hi Joe!
No can do: apples vs oranges 432 uses RF thermistors, not set up for diodes.
73
Jeff
In a message dated 2/4/2022 5:38:23 PM Eastern Standard Time, joeprice@... writes:
?
Hi Jeff,?
How about posting in files or here on how to build your own HF detector for HP432.?
Tnx? ? Joe? ?wa9cgz
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You refer to a book but no link? or how to read it alternatively it could be uploaded as a PDF to the file section on this site ??An alternatively solution to display a diode detector on an analogue display could be HP 7563A Log Voltmeter / Amplifier, as we use one in an education lab?The 415 SWR meter dues take an EXTAL input but requires a modulated RF input ?But I think trying to use a 432 for an EXTAL input is a case of using the wrong instrument for the job ? ? ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Radu Bogdan Dicher
Sent: 04 February 2022 23:20
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP detector ? Jeff, "The guy" is asking whether you'd be willing to share directions for building a suitable detector for my initial request? :) In my book, DIY is the way, if possible. Thank you much in?advance.? ? No can do: apples vs oranges 432 uses RF thermistors, not set up for diodes.
In a message dated 2/4/2022 5:38:23 PM Eastern Standard Time, joeprice@... writes:
Hi Jeff,?
How about posting in files or here on how to build your own HF detector for HP432.?
Tnx? ? Joe? ?wa9cgz
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Dave, Interesting... Very simple. Were you able to easily find a replacement for that diode? Does it look like it will be difficult to reassemble properly? (I am thinking in?its simplicity, mechanical/physical properties of geometry, contact, fit, lengths of diode terminals, etc. will have a large impact on results).? Also, are you able to measure its performance when repaired?? Radu.?
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Is this supposedly a "stock" HP diode or do you suspect it has been repaired B4 with something link a 1n34 or 1n914?
Also, is there any kind of DC block in the system (that disk could be a capacitor. If no cap, why cutoff at 100K? If they are saying that because of chopped DC, then a parallel capacitor would fix that.
Any diode detector without a DC block will be acceptable.
Cheers!
Bruce
Quoting Radu Bogdan Dicher <vondicher@...>:
toggle quoted message
Show quoted text
Dave,
Interesting... Very simple. Were you able to easily find a replacement for
that diode? Does it look like it will be difficult to reassemble properly?
(I am thinking in its simplicity, mechanical/physical properties of
geometry, contact, fit, lengths of diode terminals, etc. will have a large
impact on results).
Also, are you able to measure its performance when repaired?
Radu.
On Mon, Feb 7, 2022 at 1:53 PM Dave Wright <davewrightsplace@...>
wrote:
See /g/HP-Agilent-Keysight-equipment/album?id=272489
My 8471A, diode is fried, (well, I did find it in a dumpster...) working
on replacement, will update results when done...
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The HP 8471A OEM diode is 1N831, and there are some on eBay. I have two on the way now.
Left to right in the photo is the input termination resistor, 50 Ohms, some sort of film deposited on the disk between the BNC male center pin and a contact ring to the case. The diode anode lead is soldered directly into the input center pin at 'zero length'. ?The cathode lead passes through the center of a disk capacitor, measured as ~1500pf, and on to the center pin of the output BNC female.?
The assembly process will require care in soldering, I imagine it will go as: input R first, then output C, then screw gold plated center into the BNC male body, solder BNC female center pin to protruding cathode lead, and thread main body over all.
Intend to measure performance on 8753D VNA when completed.
More as it happens...
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Is the detector DC coupled or is there a blocking cap ?
Cheers!
Bruce
Quoting Dave Wright <davewrightsplace@...>:
toggle quoted message
Show quoted text
The HP 8471A OEM diode is 1N831, and there are some on eBay. I have two on the way now.
Left to right in the photo is the input termination resistor, 50 Ohms, some sort of film deposited on the disk between the BNC male center pin and a contact ring to the case. The diode anode lead is soldered directly into the input center pin at 'zero length'. ?The cathode lead passes through the center of a disk capacitor, measured as ~1500pf, and on to the center pin of the output BNC female.
The assembly process will require care in soldering, I imagine it will go as: input R first, then output C, then screw gold plated center into the BNC male body, solder BNC female center pin to protruding cathode lead, and thread main body over all.
Intend to measure performance on 8753D VNA when completed.
More as it happens...
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Paul Bicknell