Crystal detector?


Robin Szemeti - G1YFG
 

As I get a little closer to 3cm working ... I wanted to do some antenna measurements. Does anyone have an HP crystal detector sitting in a drawer they'd like to sell?  I need *something* to go with my HP 415E

There's an Alfred 1001 on fleabay, but I'd prefer an HP one really, a 423B or similar would be nice ...

--
Best regards,

Robin Szemeti

Redpoint Consulting Limited

E: robin@...
T: +44 (0) 1299 405028
M: +44 (0) 7971 883371

CONFIDENTIALITY NOTICE
The information contained in this e-mail is intended only for the
confidential use of the above named recipient. If you are not the
intended recipient or person responsible for delivering it to the
intended recipient, you have received this communication in error
and must not distribute or copy it.
Please accept the sender's apologies, notify the sender immediately
by return e-mail and delete this communication.

Thank you.

--
Robin Szemeti - G1YFG


cricri
 

Le 15/01/2022 à 14:41, Robin Szemeti - G1YFG via groups.io a écrit :
Alfred 1001
Hi ,

Ask marcel F1GE , he had many some time ago !

f1ge.mg@gmail.com

f1ge@sfr.fr


73

Xtian / F1VL


Robin Szemeti - G1YFG
 

Merci mon ami, je vais le contacter aujourd'hui. À bientôt.


On Sat, 15 Jan 2022 at 14:07, cricri <f1vl@...> wrote:
Le 15/01/2022 à 14:41, Robin Szemeti - G1YFG via groups.io a écrit :
> Alfred 1001

Hi ,

Ask marcel F1GE , he had many some time ago !

f1ge.mg@...

f1ge@...


73

Xtian / F1VL








--
Robin Szemeti - G1YFG


Robin Szemeti - G1YFG
 

Stand down, all sorted I think, thank you gentlemen.


On Sat, 15 Jan 2022 at 14:52, Robin Szemeti - G1YFG via groups.io <robin=redpoint.org.uk@groups.io> wrote:
Merci mon ami, je vais le contacter aujourd'hui. À bientôt.

On Sat, 15 Jan 2022 at 14:07, cricri <f1vl@...> wrote:
Le 15/01/2022 à 14:41, Robin Szemeti - G1YFG via groups.io a écrit :
> Alfred 1001

Hi ,

Ask marcel F1GE , he had many some time ago !

f1ge.mg@...

f1ge@...


73

Xtian / F1VL








--
Robin Szemeti - G1YFG


--
Robin Szemeti - G1YFG


KENT BRITAIN
 

Hi Robin

I currently own 4 HP415E's and use them very regularly on the antenna range.

Most any 1N21/1N23 detector works with them.  Including ones in Waveguide.
You need to put a 6-10 dB attenuator in front to the detector to make it look like a good 50 Ohm match and provide DC return for the diode.  I have used my with the proper detector up to 94 GHz.    For bench work they are easy enough to build using SMT diodes.

While made for a 28 volt battery pack, they do work down to 14 volts or so.  You can just mount a pair of 9V dry cell batteries, though I usually go ahead and put in 3, just inside the top cover.  The 415E only pulls about 10 ma, so the batteries last a long time.

On the back is a 0-1 Volt output designed to drive a strip chart recorder.   The 1000 Hz signal is there as well.   I like to connect that to a small audio amp and external speaker. Especially out in the field, you can easily tell if you are getting interference from other sources, and adjust for a course max signal without having to look at the meter.  

If it has not be used in a while, the range switches usually need a good cleaning.  Some spray contact cleaner and running the switches though their range will take care of that.

Good luck with your project.  Kent G8EMY/WA5VJB   

On Saturday, January 15, 2022, 07:42:12 AM CST, Robin Szemeti - G1YFG via groups.io <robin@...> wrote:


As I get a little closer to 3cm working ... I wanted to do some antenna measurements. Does anyone have an HP crystal detector sitting in a drawer they'd like to sell?  I need *something* to go with my HP 415E

There's an Alfred 1001 on fleabay, but I'd prefer an HP one really, a 423B or similar would be nice ...

--
Best regards,

Robin Szemeti

Redpoint Consulting Limited

E: robin@...
T: +44 (0) 1299 405028
M: +44 (0) 7971 883371

CONFIDENTIALITY NOTICE
The information contained in this e-mail is intended only for the
confidential use of the above named recipient. If you are not the
intended recipient or person responsible for delivering it to the
intended recipient, you have received this communication in error
and must not distribute or copy it.
Please accept the sender's apologies, notify the sender immediately
by return e-mail and delete this communication.

Thank you.

--
Robin Szemeti - G1YFG


Robin Szemeti - G1YFG
 


Hi Kent,

I'm planning to use a pair of 20dB horns to "calibrate" (ish) the setup ... I'm not sure if I will have enough power from my source which is around 80mW (a WDG multiplier chain) hopefully that will be enough for the 415 to pick up ...   thoughts?  I have a good sized field to play with ... sandy soil,  I was hoping to use the 20dB horn on the trnamsit side at about 30 metres

I was planning to use a WG16 to N transition and a coaxial crystal detector ... I've fitted the 415E with 3 x NiMh which I think will charge off the internal resistor charger thing.  If I have success with taking patterns and adjusting for best gain at 3cm, I was planning to try the same trick at 23cm as I have some ideas on yagi optimisation based on stuff done by DG7YBN and I'd really like to be in a position to take some repeatable measurements.  I was planning to build a pair (or possibly 3 ... ) short 5 element Yagis for calibration ... and from there be able to make half-decent gain estimates of my "proper" antennas ...

The 415 is a uniquely useful device, there really doesn't seem to be anything quite like it in the arsenal. Beautifully made as well, like all HP gear from that era.


On Sun, 16 Jan 2022 at 01:22, KENT BRITAIN <WA5VJB@...> wrote:
Hi Robin

I currently own 4 HP415E's and use them very regularly on the antenna range.

Most any 1N21/1N23 detector works with them.  Including ones in Waveguide.
You need to put a 6-10 dB attenuator in front to the detector to make it look like a good 50 Ohm match and provide DC return for the diode.  I have used my with the proper detector up to 94 GHz.    For bench work they are easy enough to build using SMT diodes.

While made for a 28 volt battery pack, they do work down to 14 volts or so.  You can just mount a pair of 9V dry cell batteries, though I usually go ahead and put in 3, just inside the top cover.  The 415E only pulls about 10 ma, so the batteries last a long time.

On the back is a 0-1 Volt output designed to drive a strip chart recorder.   The 1000 Hz signal is there as well.   I like to connect that to a small audio amp and external speaker. Especially out in the field, you can easily tell if you are getting interference from other sources, and adjust for a course max signal without having to look at the meter.  

If it has not be used in a while, the range switches usually need a good cleaning.  Some spray contact cleaner and running the switches though their range will take care of that.

Good luck with your project.  Kent G8EMY/WA5VJB   


--
Robin Szemeti - G1YFG


KENT BRITAIN
 

Hello Again Robin

That should be plenty of RF.
The 415E is listed as having a 1/2 uV sensitivity.

Of course the RF has to be modulated at 1000 Hz.
I usually put a PIN diode modulator on the source.
For years I used a Cavity Osc, a 10 GHz Gunn, and a 24 GHz Gunn into Pin Diodes as my source.   Most of those were much less power than your source.
And today it is easy to over drive a MMIC, pick off a harmonic with a filter, then into another MMIC.   For years my sig gen only went to 450 MHz, but I could use the harmonics this way up to 5.76 GHz     Oh I can hear it now.   When the carrier frequency is doubled, the modulation is NOT.   It's still 1000 Hz!   (Yea few extra sidebands, but no big deal!)    I have also used a 555 timer set to 1000 Hz to drive the PIN diodes.
  
For a while I had a fairly sharp 10 GHz filter and applied the 1000 Hz to the Varactor diode on the Gunn osc.   So I got my amplitude change by sending an sweeping a filter!
You have two 'screwdriver' adjustments on the front of the 415.  Frequency and Bandwidth.    Both are pretty narrow.  So adjusting your 415 to the same frequency as your modulation usually helps several dB.    Bandwidth will help reduce noise, but don't get too tight.    In the expanded scale, on a steady signal, you can read down to .05 dB.

Now the full dB range is with a Thermosister head, not a diode.   While not as sensitive, max dynamic range is with the thermositser head from the HP430 series power meter.
Thus the two options to put a bias current on the detector.  For your work I would stay with a diode detector, no bias.

With a diode head you must keep the diode in it's 'Square Law' region.  Easy enough to find where the diode goes non-linear.  Using a signal generator you will see a point in the upper 30's or lower 20's range when increasing power 2 dB only moves the meter 1 dB.

At the moment my preferred meter is actually the Marconi 6593.   It has a much larger meter.    I have 2, but one is sick.  If anyone has a schematic for the 6593, you will become my new friend!    73s Kent G8EMY/W5   


On Saturday, January 15, 2022, 09:07:21 PM CST, Robin Szemeti - G1YFG via groups.io <robin@...> wrote:



Hi Kent,

I'm planning to use a pair of 20dB horns to "calibrate" (ish) the setup ... I'm not sure if I will have enough power from my source which is around 80mW (a WDG multiplier chain) hopefully that will be enough for the 415 to pick up ...   thoughts?  I have a good sized field to play with ... sandy soil,  I was hoping to use the 20dB horn on the trnamsit side at about 30 metres

I was planning to use a WG16 to N transition and a coaxial crystal detector ... I've fitted the 415E with 3 x NiMh which I think will charge off the internal resistor charger thing.  If I have success with taking patterns and adjusting for best gain at 3cm, I was planning to try the same trick at 23cm as I have some ideas on yagi optimisation based on stuff done by DG7YBN and I'd really like to be in a position to take some repeatable measurements.  I was planning to build a pair (or possibly 3 ... ) short 5 element Yagis for calibration ... and from there be able to make half-decent gain estimates of my "proper" antennas ...

The 415 is a uniquely useful device, there really doesn't seem to be anything quite like it in the arsenal. Beautifully made as well, like all HP gear from that era.


On Sun, 16 Jan 2022 at 01:22, KENT BRITAIN <WA5VJB@...> wrote:
Hi Robin

I currently own 4 HP415E's and use them very regularly on the antenna range.

Most any 1N21/1N23 detector works with them.  Including ones in Waveguide.
You need to put a 6-10 dB attenuator in front to the detector to make it look like a good 50 Ohm match and provide DC return for the diode.  I have used my with the proper detector up to 94 GHz.    For bench work they are easy enough to build using SMT diodes.

While made for a 28 volt battery pack, they do work down to 14 volts or so.  You can just mount a pair of 9V dry cell batteries, though I usually go ahead and put in 3, just inside the top cover.  The 415E only pulls about 10 ma, so the batteries last a long time.

On the back is a 0-1 Volt output designed to drive a strip chart recorder.   The 1000 Hz signal is there as well.   I like to connect that to a small audio amp and external speaker. Especially out in the field, you can easily tell if you are getting interference from other sources, and adjust for a course max signal without having to look at the meter.  

If it has not be used in a while, the range switches usually need a good cleaning.  Some spray contact cleaner and running the switches though their range will take care of that.

Good luck with your project.  Kent G8EMY/WA5VJB   


--
Robin Szemeti - G1YFG


Dave Brown
 

Given the current discussion of the 415E etc.   I wonder if anyone has information on the Microtel 1006?

I’ve been looking for a handbook for this for several years- no luck so far.   It  appears to be fully operational but it would be great to get a handbook clear up a few queries I have regarding its use.

73 Dave, ZL3FJ

 

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of KENT BRITAIN
Sent: Sunday, January 16, 2022 18:16
To: ukmicrowaves@groups.io; UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Crystal detector?

 

Hello Again Robin

 

That should be plenty of RF.

The 415E is listed as having a 1/2 uV sensitivity.

 

Of course the RF has to be modulated at 1000 Hz.

I usually put a PIN diode modulator on the source.

For years I used a Cavity Osc, a 10 GHz Gunn, and a 24 GHz Gunn into Pin Diodes as my source.   Most of those were much less power than your source.

And today it is easy to over drive a MMIC, pick off a harmonic with a filter, then into another MMIC.   For years my sig gen only went to 450 MHz, but I could use the harmonics this way up to 5.76 GHz     Oh I can hear it now.   When the carrier frequency is doubled, the modulation is NOT.   It's still 1000 Hz!   (Yea few extra sidebands, but no big deal!)    I have also used a 555 timer set to 1000 Hz to drive the PIN diodes.

  

For a while I had a fairly sharp 10 GHz filter and applied the 1000 Hz to the Varactor diode on the Gunn osc.   So I got my amplitude change by sending an sweeping a filter!

You have two 'screwdriver' adjustments on the front of the 415.  Frequency and Bandwidth.    Both are pretty narrow.  So adjusting your 415 to the same frequency as your modulation usually helps several dB.    Bandwidth will help reduce noise, but don't get too tight.    In the expanded scale, on a steady signal, you can read down to .05 dB.

 

Now the full dB range is with a Thermosister head, not a diode.   While not as sensitive, max dynamic range is with the thermositser head from the HP430 series power meter.

Thus the two options to put a bias current on the detector.  For your work I would stay with a diode detector, no bias.

 

With a diode head you must keep the diode in it's 'Square Law' region.  Easy enough to find where the diode goes non-linear.  Using a signal generator you will see a point in the upper 30's or lower 20's range when increasing power 2 dB only moves the meter 1 dB.

 

At the moment my preferred meter is actually the Marconi 6593.   It has a much larger meter.    I have 2, but one is sick.  If anyone has a schematic for the 6593, you will become my new friend!    73s Kent G8EMY/W5   

 

 

On Saturday, January 15, 2022, 09:07:21 PM CST, Robin Szemeti - G1YFG via groups.io <robin@...> wrote:

 

 

 

Hi Kent,

 

I'm planning to use a pair of 20dB horns to "calibrate" (ish) the setup ... I'm not sure if I will have enough power from my source which is around 80mW (a WDG multiplier chain) hopefully that will be enough for the 415 to pick up ...   thoughts?  I have a good sized field to play with ... sandy soil,  I was hoping to use the 20dB horn on the trnamsit side at about 30 metres

 

I was planning to use a WG16 to N transition and a coaxial crystal detector ... I've fitted the 415E with 3 x NiMh which I think will charge off the internal resistor charger thing.  If I have success with taking patterns and adjusting for best gain at 3cm, I was planning to try the same trick at 23cm as I have some ideas on yagi optimisation based on stuff done by DG7YBN and I'd really like to be in a position to take some repeatable measurements.  I was planning to build a pair (or possibly 3 ... ) short 5 element Yagis for calibration ... and from there be able to make half-decent gain estimates of my "proper" antennas ...

 

The 415 is a uniquely useful device, there really doesn't seem to be anything quite like it in the arsenal. Beautifully made as well, like all HP gear from that era.

 

 

On Sun, 16 Jan 2022 at 01:22, KENT BRITAIN <WA5VJB@...> wrote:

Hi Robin

 

I currently own 4 HP415E's and use them very regularly on the antenna range.

 

Most any 1N21/1N23 detector works with them.  Including ones in Waveguide.

You need to put a 6-10 dB attenuator in front to the detector to make it look like a good 50 Ohm match and provide DC return for the diode.  I have used my with the proper detector up to 94 GHz.    For bench work they are easy enough to build using SMT diodes.

 

While made for a 28 volt battery pack, they do work down to 14 volts or so.  You can just mount a pair of 9V dry cell batteries, though I usually go ahead and put in 3, just inside the top cover.  The 415E only pulls about 10 ma, so the batteries last a long time.

 

On the back is a 0-1 Volt output designed to drive a strip chart recorder.   The 1000 Hz signal is there as well.   I like to connect that to a small audio amp and external speaker. Especially out in the field, you can easily tell if you are getting interference from other sources, and adjust for a course max signal without having to look at the meter.  

 

If it has not be used in a while, the range switches usually need a good cleaning.  Some spray contact cleaner and running the switches though their range will take care of that.

 

Good luck with your project.  Kent G8EMY/WA5VJB   

 


--
Robin Szemeti - G1YFG


Graham G3VKV
 

Hi Robin,
There is a Marconi version - the 6593a - very similar to the HP

  Graham G3VKV


Robin Szemeti - G1YFG
 

I've seen the Marconi, the advantage of the HP device is that it is self contained battery powered, which is useful when messing around out in fields.


On Sun, 16 Jan 2022 at 08:11, Graham G3VKV via groups.io <g3vkv=btinternet.com@groups.io> wrote:
Hi Robin,
There is a Marconi version - the 6593a - very similar to the HP

  Graham G3VKV


--
Robin Szemeti - G1YFG


KENT BRITAIN
 

My host in the UK, Sam G4DDK also has a Marconi 6593 and mounts some 9 VDC dry batteries inside.   So I now have some 9V's in mine as well.  So while not designed for a rechargeable battery pack, they can be easily battery powered.   Cheers Kent

On Sunday, January 16, 2022, 03:39:50 AM CST, Robin Szemeti - G1YFG via groups.io <robin@...> wrote:


I've seen the Marconi, the advantage of the HP device is that it is self contained battery powered, which is useful when messing around out in fields.


On Sun, 16 Jan 2022 at 08:11, Graham G3VKV via groups.io <g3vkv=btinternet.com@groups.io> wrote:
Hi Robin,
There is a Marconi version - the 6593a - very similar to the HP

  Graham G3VKV


--
Robin Szemeti - G1YFG


Roger Ray
 

On my 415E the paint on the meter has peeled away stopping the needle.
Are there ant do’s or dont’s in fixing the problem?
Thanks
Roger
G8CUB


On 16 Jan 2022, at 07:39, Dave Brown <2c39a@...> wrote:



Given the current discussion of the 415E etc.   I wonder if anyone has information on the Microtel 1006?

I’ve been looking for a handbook for this for several years- no luck so far.   It  appears to be fully operational but it would be great to get a handbook clear up a few queries I have regarding its use.

73 Dave, ZL3FJ

 

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of KENT BRITAIN
Sent: Sunday, January 16, 2022 18:16
To: ukmicrowaves@groups.io; UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Crystal detector?

 

Hello Again Robin

 

That should be plenty of RF.

The 415E is listed as having a 1/2 uV sensitivity.

 

Of course the RF has to be modulated at 1000 Hz.

I usually put a PIN diode modulator on the source.

For years I used a Cavity Osc, a 10 GHz Gunn, and a 24 GHz Gunn into Pin Diodes as my source.   Most of those were much less power than your source.

And today it is easy to over drive a MMIC, pick off a harmonic with a filter, then into another MMIC.   For years my sig gen only went to 450 MHz, but I could use the harmonics this way up to 5.76 GHz     Oh I can hear it now.   When the carrier frequency is doubled, the modulation is NOT.   It's still 1000 Hz!   (Yea few extra sidebands, but no big deal!)    I have also used a 555 timer set to 1000 Hz to drive the PIN diodes.

  

For a while I had a fairly sharp 10 GHz filter and applied the 1000 Hz to the Varactor diode on the Gunn osc.   So I got my amplitude change by sending an sweeping a filter!

You have two 'screwdriver' adjustments on the front of the 415.  Frequency and Bandwidth.    Both are pretty narrow.  So adjusting your 415 to the same frequency as your modulation usually helps several dB.    Bandwidth will help reduce noise, but don't get too tight.    In the expanded scale, on a steady signal, you can read down to .05 dB.

 

Now the full dB range is with a Thermosister head, not a diode.   While not as sensitive, max dynamic range is with the thermositser head from the HP430 series power meter.

Thus the two options to put a bias current on the detector.  For your work I would stay with a diode detector, no bias.

 

With a diode head you must keep the diode in it's 'Square Law' region.  Easy enough to find where the diode goes non-linear.  Using a signal generator you will see a point in the upper 30's or lower 20's range when increasing power 2 dB only moves the meter 1 dB.

 

At the moment my preferred meter is actually the Marconi 6593.   It has a much larger meter.    I have 2, but one is sick.  If anyone has a schematic for the 6593, you will become my new friend!    73s Kent G8EMY/W5   

 

 

On Saturday, January 15, 2022, 09:07:21 PM CST, Robin Szemeti - G1YFG via groups.io <robin@...> wrote:

 

 

 

Hi Kent,

 

I'm planning to use a pair of 20dB horns to "calibrate" (ish) the setup ... I'm not sure if I will have enough power from my source which is around 80mW (a WDG multiplier chain) hopefully that will be enough for the 415 to pick up ...   thoughts?  I have a good sized field to play with ... sandy soil,  I was hoping to use the 20dB horn on the trnamsit side at about 30 metres

 

I was planning to use a WG16 to N transition and a coaxial crystal detector ... I've fitted the 415E with 3 x NiMh which I think will charge off the internal resistor charger thing.  If I have success with taking patterns and adjusting for best gain at 3cm, I was planning to try the same trick at 23cm as I have some ideas on yagi optimisation based on stuff done by DG7YBN and I'd really like to be in a position to take some repeatable measurements.  I was planning to build a pair (or possibly 3 ... ) short 5 element Yagis for calibration ... and from there be able to make half-decent gain estimates of my "proper" antennas ...

 

The 415 is a uniquely useful device, there really doesn't seem to be anything quite like it in the arsenal. Beautifully made as well, like all HP gear from that era.

 

 

On Sun, 16 Jan 2022 at 01:22, KENT BRITAIN <WA5VJB@...> wrote:

Hi Robin

 

I currently own 4 HP415E's and use them very regularly on the antenna range.

 

Most any 1N21/1N23 detector works with them.  Including ones in Waveguide.

You need to put a 6-10 dB attenuator in front to the detector to make it look like a good 50 Ohm match and provide DC return for the diode.  I have used my with the proper detector up to 94 GHz.    For bench work they are easy enough to build using SMT diodes.

 

While made for a 28 volt battery pack, they do work down to 14 volts or so.  You can just mount a pair of 9V dry cell batteries, though I usually go ahead and put in 3, just inside the top cover.  The 415E only pulls about 10 ma, so the batteries last a long time.

 

On the back is a 0-1 Volt output designed to drive a strip chart recorder.   The 1000 Hz signal is there as well.   I like to connect that to a small audio amp and external speaker. Especially out in the field, you can easily tell if you are getting interference from other sources, and adjust for a course max signal without having to look at the meter.  

 

If it has not be used in a while, the range switches usually need a good cleaning.  Some spray contact cleaner and running the switches though their range will take care of that.

 

Good luck with your project.  Kent G8EMY/WA5VJB   

 


--
Robin Szemeti - G1YFG

<microtel1006.jpg>


KENT BRITAIN
 

Hi Roger

Yea, the used a Decal on most of the 415E's for the scale.   Sunlight and humidity can make the edges peal back.  Depending on where the scale has pealed back, I have taken a sharp knife and cut away the part that the pointer hits.   It extends the life of the meter.

Kent

On Sunday, January 16, 2022, 09:50:39 AM CST, Roger Ray via groups.io <g8cub@...> wrote:


On my 415E the paint on the meter has peeled away stopping the needle.
Are there ant do’s or dont’s in fixing the problem?
Thanks
Roger
G8CUB


On 16 Jan 2022, at 07:39, Dave Brown <2c39a@...> wrote:



Given the current discussion of the 415E etc.   I wonder if anyone has information on the Microtel 1006?

I’ve been looking for a handbook for this for several years- no luck so far.   It  appears to be fully operational but it would be great to get a handbook clear up a few queries I have regarding its use.

73 Dave, ZL3FJ

 

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of KENT BRITAIN
Sent: Sunday, January 16, 2022 18:16
To: ukmicrowaves@groups.io; UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Crystal detector?

 

Hello Again Robin

 

That should be plenty of RF.

The 415E is listed as having a 1/2 uV sensitivity.

 

Of course the RF has to be modulated at 1000 Hz.

I usually put a PIN diode modulator on the source.

For years I used a Cavity Osc, a 10 GHz Gunn, and a 24 GHz Gunn into Pin Diodes as my source.   Most of those were much less power than your source.

And today it is easy to over drive a MMIC, pick off a harmonic with a filter, then into another MMIC.   For years my sig gen only went to 450 MHz, but I could use the harmonics this way up to 5.76 GHz     Oh I can hear it now.   When the carrier frequency is doubled, the modulation is NOT.   It's still 1000 Hz!   (Yea few extra sidebands, but no big deal!)    I have also used a 555 timer set to 1000 Hz to drive the PIN diodes.

  

For a while I had a fairly sharp 10 GHz filter and applied the 1000 Hz to the Varactor diode on the Gunn osc.   So I got my amplitude change by sending an sweeping a filter!

You have two 'screwdriver' adjustments on the front of the 415.  Frequency and Bandwidth.    Both are pretty narrow.  So adjusting your 415 to the same frequency as your modulation usually helps several dB.    Bandwidth will help reduce noise, but don't get too tight.    In the expanded scale, on a steady signal, you can read down to .05 dB.

 

Now the full dB range is with a Thermosister head, not a diode.   While not as sensitive, max dynamic range is with the thermositser head from the HP430 series power meter.

Thus the two options to put a bias current on the detector.  For your work I would stay with a diode detector, no bias.

 

With a diode head you must keep the diode in it's 'Square Law' region.  Easy enough to find where the diode goes non-linear.  Using a signal generator you will see a point in the upper 30's or lower 20's range when increasing power 2 dB only moves the meter 1 dB.

 

At the moment my preferred meter is actually the Marconi 6593.   It has a much larger meter.    I have 2, but one is sick.  If anyone has a schematic for the 6593, you will become my new friend!    73s Kent G8EMY/W5   

 

 

On Saturday, January 15, 2022, 09:07:21 PM CST, Robin Szemeti - G1YFG via groups.io <robin@...> wrote:

 

 

 

Hi Kent,

 

I'm planning to use a pair of 20dB horns to "calibrate" (ish) the setup ... I'm not sure if I will have enough power from my source which is around 80mW (a WDG multiplier chain) hopefully that will be enough for the 415 to pick up ...   thoughts?  I have a good sized field to play with ... sandy soil,  I was hoping to use the 20dB horn on the trnamsit side at about 30 metres

 

I was planning to use a WG16 to N transition and a coaxial crystal detector ... I've fitted the 415E with 3 x NiMh which I think will charge off the internal resistor charger thing.  If I have success with taking patterns and adjusting for best gain at 3cm, I was planning to try the same trick at 23cm as I have some ideas on yagi optimisation based on stuff done by DG7YBN and I'd really like to be in a position to take some repeatable measurements.  I was planning to build a pair (or possibly 3 ... ) short 5 element Yagis for calibration ... and from there be able to make half-decent gain estimates of my "proper" antennas ...

 

The 415 is a uniquely useful device, there really doesn't seem to be anything quite like it in the arsenal. Beautifully made as well, like all HP gear from that era.

 

 

On Sun, 16 Jan 2022 at 01:22, KENT BRITAIN <WA5VJB@...> wrote:

Hi Robin

 

I currently own 4 HP415E's and use them very regularly on the antenna range.

 

Most any 1N21/1N23 detector works with them.  Including ones in Waveguide.

You need to put a 6-10 dB attenuator in front to the detector to make it look like a good 50 Ohm match and provide DC return for the diode.  I have used my with the proper detector up to 94 GHz.    For bench work they are easy enough to build using SMT diodes.

 

While made for a 28 volt battery pack, they do work down to 14 volts or so.  You can just mount a pair of 9V dry cell batteries, though I usually go ahead and put in 3, just inside the top cover.  The 415E only pulls about 10 ma, so the batteries last a long time.

 

On the back is a 0-1 Volt output designed to drive a strip chart recorder.   The 1000 Hz signal is there as well.   I like to connect that to a small audio amp and external speaker. Especially out in the field, you can easily tell if you are getting interference from other sources, and adjust for a course max signal without having to look at the meter.  

 

If it has not be used in a while, the range switches usually need a good cleaning.  Some spray contact cleaner and running the switches though their range will take care of that.

 

Good luck with your project.  Kent G8EMY/WA5VJB   

 


--
Robin Szemeti - G1YFG

<microtel1006.jpg>


Robin Szemeti - G1YFG
 

I used very watered down PVA and a fine brush in the past to fix HP meters of that vintage, with good results.

You may not know, but each meter face was individually photo-plotted to match the linearity of the meter movement, as such there are no "standard" meter scales that can be printed out to use. 

Normally, you'll find the "clear" sections have peeled up, where the "black" sections have remained intact.   A very fine paintbrush and a little watered down PVA glue, brushed carefully under the peeled sections and then smoothed down works well. My vector voltmeter was badly peeled, and worse, had rust in the movement ... but it is all correct now.



On Sun, 16 Jan 2022 at 15:50, Roger Ray via groups.io <g8cub=yahoo.co.uk@groups.io> wrote:
On my 415E the paint on the meter has peeled away stopping the needle.
Are there ant do’s or dont’s in fixing the problem?
Thanks
Roger
G8CUB


On 16 Jan 2022, at 07:39, Dave Brown <2c39a@...> wrote:



Given the current discussion of the 415E etc.   I wonder if anyone has information on the Microtel 1006?

I’ve been looking for a handbook for this for several years- no luck so far.   It  appears to be fully operational but it would be great to get a handbook clear up a few queries I have regarding its use.

73 Dave, ZL3FJ

 

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of KENT BRITAIN
Sent: Sunday, January 16, 2022 18:16
To: ukmicrowaves@groups.io; UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Crystal detector?

 

Hello Again Robin

 

That should be plenty of RF.

The 415E is listed as having a 1/2 uV sensitivity.

 

Of course the RF has to be modulated at 1000 Hz.

I usually put a PIN diode modulator on the source.

For years I used a Cavity Osc, a 10 GHz Gunn, and a 24 GHz Gunn into Pin Diodes as my source.   Most of those were much less power than your source.

And today it is easy to over drive a MMIC, pick off a harmonic with a filter, then into another MMIC.   For years my sig gen only went to 450 MHz, but I could use the harmonics this way up to 5.76 GHz     Oh I can hear it now.   When the carrier frequency is doubled, the modulation is NOT.   It's still 1000 Hz!   (Yea few extra sidebands, but no big deal!)    I have also used a 555 timer set to 1000 Hz to drive the PIN diodes.

  

For a while I had a fairly sharp 10 GHz filter and applied the 1000 Hz to the Varactor diode on the Gunn osc.   So I got my amplitude change by sending an sweeping a filter!

You have two 'screwdriver' adjustments on the front of the 415.  Frequency and Bandwidth.    Both are pretty narrow.  So adjusting your 415 to the same frequency as your modulation usually helps several dB.    Bandwidth will help reduce noise, but don't get too tight.    In the expanded scale, on a steady signal, you can read down to .05 dB.

 

Now the full dB range is with a Thermosister head, not a diode.   While not as sensitive, max dynamic range is with the thermositser head from the HP430 series power meter.

Thus the two options to put a bias current on the detector.  For your work I would stay with a diode detector, no bias.

 

With a diode head you must keep the diode in it's 'Square Law' region.  Easy enough to find where the diode goes non-linear.  Using a signal generator you will see a point in the upper 30's or lower 20's range when increasing power 2 dB only moves the meter 1 dB.

 

At the moment my preferred meter is actually the Marconi 6593.   It has a much larger meter.    I have 2, but one is sick.  If anyone has a schematic for the 6593, you will become my new friend!    73s Kent G8EMY/W5   

 

 

On Saturday, January 15, 2022, 09:07:21 PM CST, Robin Szemeti - G1YFG via groups.io <robin=redpoint.org.uk@groups.io> wrote:

 

 

 

Hi Kent,

 

I'm planning to use a pair of 20dB horns to "calibrate" (ish) the setup ... I'm not sure if I will have enough power from my source which is around 80mW (a WDG multiplier chain) hopefully that will be enough for the 415 to pick up ...   thoughts?  I have a good sized field to play with ... sandy soil,  I was hoping to use the 20dB horn on the trnamsit side at about 30 metres

 

I was planning to use a WG16 to N transition and a coaxial crystal detector ... I've fitted the 415E with 3 x NiMh which I think will charge off the internal resistor charger thing.  If I have success with taking patterns and adjusting for best gain at 3cm, I was planning to try the same trick at 23cm as I have some ideas on yagi optimisation based on stuff done by DG7YBN and I'd really like to be in a position to take some repeatable measurements.  I was planning to build a pair (or possibly 3 ... ) short 5 element Yagis for calibration ... and from there be able to make half-decent gain estimates of my "proper" antennas ...

 

The 415 is a uniquely useful device, there really doesn't seem to be anything quite like it in the arsenal. Beautifully made as well, like all HP gear from that era.

 

 

On Sun, 16 Jan 2022 at 01:22, KENT BRITAIN <WA5VJB@...> wrote:

Hi Robin

 

I currently own 4 HP415E's and use them very regularly on the antenna range.

 

Most any 1N21/1N23 detector works with them.  Including ones in Waveguide.

You need to put a 6-10 dB attenuator in front to the detector to make it look like a good 50 Ohm match and provide DC return for the diode.  I have used my with the proper detector up to 94 GHz.    For bench work they are easy enough to build using SMT diodes.

 

While made for a 28 volt battery pack, they do work down to 14 volts or so.  You can just mount a pair of 9V dry cell batteries, though I usually go ahead and put in 3, just inside the top cover.  The 415E only pulls about 10 ma, so the batteries last a long time.

 

On the back is a 0-1 Volt output designed to drive a strip chart recorder.   The 1000 Hz signal is there as well.   I like to connect that to a small audio amp and external speaker. Especially out in the field, you can easily tell if you are getting interference from other sources, and adjust for a course max signal without having to look at the meter.  

 

If it has not be used in a while, the range switches usually need a good cleaning.  Some spray contact cleaner and running the switches though their range will take care of that.

 

Good luck with your project.  Kent G8EMY/WA5VJB   

 


--
Robin Szemeti - G1YFG

<microtel1006.jpg>


--
Robin Szemeti - G1YFG


Conrad, PA5Y
 

Can we not send it to ‘the repair shop’ 😊

 

Conrad

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Robin Szemeti - G1YFG via groups.io
Sent: 16 January 2022 21:23
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Crystal detector?

 

I used very watered down PVA and a fine brush in the past to fix HP meters of that vintage, with good results.

 

You may not know, but each meter face was individually photo-plotted to match the linearity of the meter movement, as such there are no "standard" meter scales that can be printed out to use. 

 

Normally, you'll find the "clear" sections have peeled up, where the "black" sections have remained intact.   A very fine paintbrush and a little watered down PVA glue, brushed carefully under the peeled sections and then smoothed down works well. My vector voltmeter was badly peeled, and worse, had rust in the movement ... but it is all correct now.

 

 

 

On Sun, 16 Jan 2022 at 15:50, Roger Ray via groups.io <g8cub=yahoo.co.uk@groups.io> wrote:

On my 415E the paint on the meter has peeled away stopping the needle.

Are there ant do’s or dont’s in fixing the problem?

Thanks

Roger

G8CUB



On 16 Jan 2022, at 07:39, Dave Brown <2c39a@...> wrote:



Given the current discussion of the 415E etc.   I wonder if anyone has information on the Microtel 1006?

I’ve been looking for a handbook for this for several years- no luck so far.   It  appears to be fully operational but it would be great to get a handbook clear up a few queries I have regarding its use.

73 Dave, ZL3FJ

 

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of KENT BRITAIN
Sent: Sunday, January 16, 2022 18:16
To: ukmicrowaves@groups.io; UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Crystal detector?

 

Hello Again Robin

 

That should be plenty of RF.

The 415E is listed as having a 1/2 uV sensitivity.

 

Of course the RF has to be modulated at 1000 Hz.

I usually put a PIN diode modulator on the source.

For years I used a Cavity Osc, a 10 GHz Gunn, and a 24 GHz Gunn into Pin Diodes as my source.   Most of those were much less power than your source.

And today it is easy to over drive a MMIC, pick off a harmonic with a filter, then into another MMIC.   For years my sig gen only went to 450 MHz, but I could use the harmonics this way up to 5.76 GHz     Oh I can hear it now.   When the carrier frequency is doubled, the modulation is NOT.   It's still 1000 Hz!   (Yea few extra sidebands, but no big deal!)    I have also used a 555 timer set to 1000 Hz to drive the PIN diodes.

  

For a while I had a fairly sharp 10 GHz filter and applied the 1000 Hz to the Varactor diode on the Gunn osc.   So I got my amplitude change by sending an sweeping a filter!

You have two 'screwdriver' adjustments on the front of the 415.  Frequency and Bandwidth.    Both are pretty narrow.  So adjusting your 415 to the same frequency as your modulation usually helps several dB.    Bandwidth will help reduce noise, but don't get too tight.    In the expanded scale, on a steady signal, you can read down to .05 dB.

 

Now the full dB range is with a Thermosister head, not a diode.   While not as sensitive, max dynamic range is with the thermositser head from the HP430 series power meter.

Thus the two options to put a bias current on the detector.  For your work I would stay with a diode detector, no bias.

 

With a diode head you must keep the diode in it's 'Square Law' region.  Easy enough to find where the diode goes non-linear.  Using a signal generator you will see a point in the upper 30's or lower 20's range when increasing power 2 dB only moves the meter 1 dB.

 

At the moment my preferred meter is actually the Marconi 6593.   It has a much larger meter.    I have 2, but one is sick.  If anyone has a schematic for the 6593, you will become my new friend!    73s Kent G8EMY/W5   

 

 

On Saturday, January 15, 2022, 09:07:21 PM CST, Robin Szemeti - G1YFG via groups.io <robin=redpoint.org.uk@groups.io> wrote:

 

 

 

Hi Kent,

 

I'm planning to use a pair of 20dB horns to "calibrate" (ish) the setup ... I'm not sure if I will have enough power from my source which is around 80mW (a WDG multiplier chain) hopefully that will be enough for the 415 to pick up ...   thoughts?  I have a good sized field to play with ... sandy soil,  I was hoping to use the 20dB horn on the trnamsit side at about 30 metres

 

I was planning to use a WG16 to N transition and a coaxial crystal detector ... I've fitted the 415E with 3 x NiMh which I think will charge off the internal resistor charger thing.  If I have success with taking patterns and adjusting for best gain at 3cm, I was planning to try the same trick at 23cm as I have some ideas on yagi optimisation based on stuff done by DG7YBN and I'd really like to be in a position to take some repeatable measurements.  I was planning to build a pair (or possibly 3 ... ) short 5 element Yagis for calibration ... and from there be able to make half-decent gain estimates of my "proper" antennas ...

 

The 415 is a uniquely useful device, there really doesn't seem to be anything quite like it in the arsenal. Beautifully made as well, like all HP gear from that era.

 

 

On Sun, 16 Jan 2022 at 01:22, KENT BRITAIN <WA5VJB@...> wrote:

Hi Robin

 

I currently own 4 HP415E's and use them very regularly on the antenna range.

 

Most any 1N21/1N23 detector works with them.  Including ones in Waveguide.

You need to put a 6-10 dB attenuator in front to the detector to make it look like a good 50 Ohm match and provide DC return for the diode.  I have used my with the proper detector up to 94 GHz.    For bench work they are easy enough to build using SMT diodes.

 

While made for a 28 volt battery pack, they do work down to 14 volts or so.  You can just mount a pair of 9V dry cell batteries, though I usually go ahead and put in 3, just inside the top cover.  The 415E only pulls about 10 ma, so the batteries last a long time.

 

On the back is a 0-1 Volt output designed to drive a strip chart recorder.   The 1000 Hz signal is there as well.   I like to connect that to a small audio amp and external speaker. Especially out in the field, you can easily tell if you are getting interference from other sources, and adjust for a course max signal without having to look at the meter.  

 

If it has not be used in a while, the range switches usually need a good cleaning.  Some spray contact cleaner and running the switches though their range will take care of that.

 

Good luck with your project.  Kent G8EMY/WA5VJB   

 


--
Robin Szemeti - G1YFG

<microtel1006.jpg>


--
Robin Szemeti - G1YFG


Dave G8KHU
 

Hi Roger

There are several threads with useful information on the HP group, search "meter scales"

https://groups.io/g/HP-Agilent-Keysight-equipment

73 Dave


Roger Ray
 

Thanks for all the input. That gives me a lot of information to allow me to sort out the meter scale.
Hopefully I will be able to make use of it soon.
Roger
G8CUB


On 17 Jan 2022, at 08:02, Dave G8KHU <david@...> wrote:

Hi Roger

There are several threads with useful information on the HP group, search "meter scales"

https://groups.io/g/HP-Agilent-Keysight-equipment

73 Dave