Wanted - surplus box with large panel meter


g4cch_1
 

I am building a noise power meter, and am looking for surplus box with a large panel meter. Ideally the meter should be 500uA or 1mA. An old power supply, or anything non functional with a large panel meter may be suitable.

Please email me offline if you have anything that may be suitable, with a photo and dimensions.

Thanks and 73
Howard, G4CCH


Adrian G4UVZ
 

Not sure if this is any good ..meter I am pretty sure has a shunt...contains a 12 volt working PSU 

Adrian


g4cch_1
 

OK Adrian, the meter looks a bit small for my purposes.

Has anyone in the UK got a non working HP432 or 435 Power Meter?

Thanks and 73
Howard


Colin Ranson
 

Howard,

 

I have a brand new, never used but old stock HP 435, Dated 1983 (I think ) Bought in anticipation of getting a head, but never happened.  Now using a 10GHz log detector.

 

g8lbs@...

 

regards

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: g4cch_1
Sent: 26 August 2020 17:58
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Wanted - surplus box with large panel meter

 

OK Adrian, the meter looks a bit small for my purposes.

Has anyone in the UK got a non working HP432 or 435 Power Meter?

Thanks and 73
Howard

 


 

On Wed, 26 Aug 2020 at 13:29, g4cch_1 <g4cch_1@...> wrote:
I am building a noise power meter, and am looking for surplus box with a large panel meter. Ideally the meter should be 500uA or 1mA. An old power supply, or anything non functional with a large panel meter may be suitable.

Please email me offline if you have anything that may be suitable, with a photo and dimensions.

Thanks and 73
Howard, G4CCH

How about getting an old AVO meter? That will have a mirrored scale, so about the best you will get. 

To what sort of uncertainty do you expect to be able to measure noise power? I don’t really see why you need a large meter to measure something that you are not going to be able to measure very accurately. The needle is not even going to be stationary when making a measurement of noise power, so I don’t think even quantitative measurements require a large meter. 

Dave
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom


Robin Szemeti - G1YFG
 

If you average the reading over a sufficient length of time, it should be stable enough ... I would have thought these days a digital meter and a suitably large R/C network might have been the way to go.


On Wed, 26 Aug 2020 at 20:24, Dr. David Kirkby, Kirkby Microwave Ltd <drkirkby@...> wrote:
On Wed, 26 Aug 2020 at 13:29, g4cch_1 <g4cch_1@...> wrote:
I am building a noise power meter, and am looking for surplus box with a large panel meter. Ideally the meter should be 500uA or 1mA. An old power supply, or anything non functional with a large panel meter may be suitable.

Please email me offline if you have anything that may be suitable, with a photo and dimensions.

Thanks and 73
Howard, G4CCH

How about getting an old AVO meter? That will have a mirrored scale, so about the best you will get. 

To what sort of uncertainty do you expect to be able to measure noise power? I don’t really see why you need a large meter to measure something that you are not going to be able to measure very accurately. The needle is not even going to be stationary when making a measurement of noise power, so I don’t think even quantitative measurements require a large meter. 

Dave
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom


--
Robin Szemeti - G1YFG


Andy G4JNT
 

Or a line-of-LEDs.   Noise provides sufficient jitter to give a smooth transition from one LED to the next
Or a bar-graph on a PC



On Wed, 26 Aug 2020 at 21:32, Robin Szemeti - G1YFG <robin@...> wrote:
If you average the reading over a sufficient length of time, it should be stable enough ... I would have thought these days a digital meter and a suitably large R/C network might have been the way to go.


On Wed, 26 Aug 2020 at 20:24, Dr. David Kirkby, Kirkby Microwave Ltd <drkirkby@...> wrote:
On Wed, 26 Aug 2020 at 13:29, g4cch_1 <g4cch_1@...> wrote:
I am building a noise power meter, and am looking for surplus box with a large panel meter. Ideally the meter should be 500uA or 1mA. An old power supply, or anything non functional with a large panel meter may be suitable.

Please email me offline if you have anything that may be suitable, with a photo and dimensions.

Thanks and 73
Howard, G4CCH

How about getting an old AVO meter? That will have a mirrored scale, so about the best you will get. 

To what sort of uncertainty do you expect to be able to measure noise power? I don’t really see why you need a large meter to measure something that you are not going to be able to measure very accurately. The needle is not even going to be stationary when making a measurement of noise power, so I don’t think even quantitative measurements require a large meter. 

Dave
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom


--
Robin Szemeti - G1YFG


Conrad, PA5Y
 

I think that the idea of a big meter is so that moon noise can be peaked easily, a slow damped movement such as an AVO is really not what you want for that. You want something fairly fast but big so that you can easily see small changes. I am pretty sure that Howard is not trying to make a lab grade instrument.

 

Regards

 

Conrad PA5Y

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Dr. David Kirkby, Kirkby Microwave Ltd via groups.io
Sent: 26 August 2020 21:24
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Wanted - surplus box with large panel meter

 

On Wed, 26 Aug 2020 at 13:29, g4cch_1 <g4cch_1@...> wrote:

I am building a noise power meter, and am looking for surplus box with a large panel meter. Ideally the meter should be 500uA or 1mA. An old power supply, or anything non functional with a large panel meter may be suitable.

Please email me offline if you have anything that may be suitable, with a photo and dimensions.

Thanks and 73
Howard, G4CCH

 

How about getting an old AVO meter? That will have a mirrored scale, so about the best you will get. 

 

To what sort of uncertainty do you expect to be able to measure noise power? I don’t really see why you need a large meter to measure something that you are not going to be able to measure very accurately. The needle is not even going to be stationary when making a measurement of noise power, so I don’t think even quantitative measurements require a large meter. 

 

Dave

--

Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom


Adrian G4UVZ
 

If you are looking for a hi quality analogue meter ..I have this 60microamp movement with over 6 inch active scale ..mirrored of course !
You can't beat an analgue meter for tweaking!  digital is fine for an absolute measurement ..but for tweaking with digital the brain has to do continuous D to A conversion!!! ...........discuss
Adrian

Pm me if this is of interest


Graham - G3YJR
 

Or this? I paid a fiver for it at Newark rally & then never used it.

Graham - Sheffield


g4cch_1
 

Thanks Conrad, that's exactly what I am trying to achieve - but on a tight budget.
Also the thought of recycling defunct equipment with usable parts in it appeals to me, if I can find it and at the right price.
Something like an HP432 or 435 is what I am looking for - just for the case and the meter.
New cases are expensive, and not what I really want or need for this project.

My project is based on VK3NX's noise meter - http://www.vk3nx.com/files/Noise_Meter.pdf
I know this is "old school" technology, but it's what I want right now, and I have the RF end of the project complete already.

Regarding the meter and accuracy. VK3NX refers to this in his article:

Page 8
In practical application I found that the meter can have a FSD representing as little as 0.5dB increase in input level and still have excellent stability and accuracy as verified with a HP Signal generator as the calibrating source.

The Absolute input levels are not critical (provided they are within the useable range of the AD8307).  The RELATIVE MEASUREMENTS ARE VERY ACCURATE provided care is taken in setting up the response of the AD8307 and calibrating the resistance multipliers correctly.

Page 10
For accuracy and ease of use the biggest faced panel meter possible should be used.

I just need to get the project finished as I need to move on and get on with other stuff outside as the WX is beginning to look like autumn already.
The azimuth drive on my EME dish is really getting to be unusable on 13cm and up, so will need some work to try and keep it going, or an expensive replacement.
Expense is not an option right now...

Thanks and 73
Howard, G4CCH


Neil Smith G4DBN
 

HP3400s with blown thermal sensors are also a good choice for a project box needing a big panel meter.  I have a working HP3400A thermal "true RMS" AC millivoltmeter that I use for noise measurements.  The thermal sensor has just the right feel for this sort of thing. I also have a Fluke 2922A, which is all digital. Spiffier, but not ideal for incremental measurements.  Same with my old HP435B power meter. I use that for tweaking and the later digital versions for absolute measurements. I also have a Marconi 6460 but it has a working WG16 sensor head, so I'm hanging on to that!

I like to view the meters remotely using binoculars when testing antennas. Also, tweaking the gain and offset of an analogue (or digitised with analogue display) meter expands the scale nicely for incremental adjustments.

A modern alternative is to use a large e-ink display panel with a PIC or Arduino driving it, then you can make the graphic display of a panel meter look and respond exactly as you want, but you still have to find a case. 

Sorry I don't have any spare boxes with meters.

Neil G4DBN

On 27/08/2020 10:48, g4cch_1 wrote:

Thanks Conrad, that's exactly what I am trying to achieve - but on a tight budget.
Also the thought of recycling defunct equipment with usable parts in it appeals to me, if I can find it and at the right price.
Something like an HP432 or 435 is what I am looking for - just for the case and the meter.
New cases are expensive, and not what I really want or need for this project.

My project is based on VK3NX's noise meter - http://www.vk3nx.com/files/Noise_Meter.pdf
I know this is "old school" technology, but it's what I want right now, and I have the RF end of the project complete already.

Regarding the meter and accuracy. VK3NX refers to this in his article:

Page 8
In practical application I found that the meter can have a FSD representing as little as 0.5dB increase in input level and still have excellent stability and accuracy as verified with a HP Signal generator as the calibrating source.

The Absolute input levels are not critical (provided they are within the useable range of the AD8307).  The RELATIVE MEASUREMENTS ARE VERY ACCURATE provided care is taken in setting up the response of the AD8307 and calibrating the resistance multipliers correctly.

Page 10
For accuracy and ease of use the biggest faced panel meter possible should be used.

I just need to get the project finished as I need to move on and get on with other stuff outside as the WX is beginning to look like autumn already.
The azimuth drive on my EME dish is really getting to be unusable on 13cm and up, so will need some work to try and keep it going, or an expensive replacement.
Expense is not an option right now...

Thanks and 73
Howard, G4CCH

_._,_._,_


militaryoperator
 

Thanks Conrad, that's exactly what I am trying to achieve - but on a tight budget.
---------------------------------


£3 from Telford rally. Control box for my 10Ghz trvrt. Meter connected to mon pin on pa, 4 wire connection, volts, ptt and monitor. 

ex Matthew Boulton College lab gear, bought off Soth Brum club stall if I recall. 

meter.jpg


 

On Thu, 27 Aug 2020 at 11:56, Neil Smith G4DBN <neil@...> wrote:

I like to view the meters remotely using binoculars when testing antennas.


I have never tried it, but a speaker driven by an audio oscillator with an output which changes volume and/or frequency, might be a way of adjusting something for minimum or maximum without actually looking at it. I would assume frequency would be more suitable than volume, but I don’t know. 

Neil G4DBN


G8WRB 
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom


Gordon REASON <gordonj.reason@...>
 

Sounds like a voltage controlled Audio Oscillator is needed ........... quite easy to do .

On 27 August 2020 at 13:38 "Dr. David Kirkby, Kirkby Microwave Ltd" <drkirkby@...> wrote:

On Thu, 27 Aug 2020 at 11:56, Neil Smith G4DBN < neil@...> wrote:

I like to view the meters remotely using binoculars when testing antennas.


I have never tried it, but a speaker driven by an audio oscillator with an output which changes volume and/or frequency, might be a way of adjusting something for minimum or maximum without actually looking at it. I would assume frequency would be more suitable than volume, but I don’t know. 

Neil G4DBN


G8WRB 
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom


Dave G8KHU
 

In the days of WBFM on 10GHz I used to use an audio VCO (CD4046) connected to the S meter as a dish alignment aid. I found it highly effective, especially as you could send the tone back over the talkback link to the other station as well. While I'm not tone deaf, neither am I very musical, but it was easy to distinguish "getting higher" from "getting lower" even on a windy/rainy hilltop.

Dave G8KHU


John Fell
 

A design using that device was published in one of Peter, G3PHO's , paper Microwave Newsletters and in the Microwave Newsletter Technical Collection ,
G4ERP has a circuit for an Audio Voltmeter in section 15.3 .

73
John
G0API
 


On Thu, 27 Aug 2020 at 14:31, Dave G8KHU <david@...> wrote:
In the days of WBFM on 10GHz I used to use an audio VCO (CD4046) connected to the S meter as a dish alignment aid. I found it highly effective, especially as you could send the tone back over the talkback link to the other station as well. While I'm not tone deaf, neither am I very musical, but it was easy to distinguish "getting higher" from "getting lower" even on a windy/rainy hilltop.

Dave G8KHU


Neil Smith G4DBN
 

Perfect for annoying the neighbours, plus the receive system is 40 metres away, and through two sets of windows, one of which doesn't open, so slightly awkward in this specific location.

Definitely a good way to tweak things though, as you don't have to look at the meter.  My 3400A even has a smoothed and buffered 0 to -1V DC output that is (sort-of) perfect for the job. The HP435B has a 0 to +1 V DC output which can be used  just the same.

I remember an audio tone SWR meter being used to tweak up the gamma match on a beam at a contest site sometime last century. It was set to lower SWR=higher frequency tone for some pseudopsychological reason.

Neil G4DBN

On 27/08/2020 14:30, Gordon REASON via groups.io wrote:

Sounds like a voltage controlled Audio Oscillator is needed ........... quite easy to do .

On 27 August 2020 at 13:38 "Dr. David Kirkby, Kirkby Microwave Ltd" <drkirkby@...> wrote:

On Thu, 27 Aug 2020 at 11:56, Neil Smith G4DBN < neil@...> wrote:

I like to view the meters remotely using binoculars when testing antennas.


I have never tried it, but a speaker driven by an audio oscillator with an output which changes volume and/or frequency, might be a way of adjusting something for minimum or maximum without actually looking at it. I would assume frequency would be more suitable than volume, but I don’t know. 


Andy G4JNT
 

Another way, use a smartphone and its WiFi linked to your PC as a remote video camera to look at the meter
(having recently downloaded iVCam to do just this)
 


On Thu, 27 Aug 2020 at 15:33, Neil Smith G4DBN <neil@...> wrote:

Perfect for annoying the neighbours, plus the receive system is 40 metres away, and through two sets of windows, one of which doesn't open, so slightly awkward in this specific location.

Definitely a good way to tweak things though, as you don't have to look at the meter.  My 3400A even has a smoothed and buffered 0 to -1V DC output that is (sort-of) perfect for the job. The HP435B has a 0 to +1 V DC output which can be used  just the same.

I remember an audio tone SWR meter being used to tweak up the gamma match on a beam at a contest site sometime last century. It was set to lower SWR=higher frequency tone for some pseudopsychological reason.

Neil G4DBN

On 27/08/2020 14:30, Gordon REASON via groups.io wrote:

Sounds like a voltage controlled Audio Oscillator is needed ........... quite easy to do .

On 27 August 2020 at 13:38 "Dr. David Kirkby, Kirkby Microwave Ltd" <drkirkby@...> wrote:

On Thu, 27 Aug 2020 at 11:56, Neil Smith G4DBN < neil@...> wrote:

I like to view the meters remotely using binoculars when testing antennas.


I have never tried it, but a speaker driven by an audio oscillator with an output which changes volume and/or frequency, might be a way of adjusting something for minimum or maximum without actually looking at it. I would assume frequency would be more suitable than volume, but I don’t know. 


John Quarmby
 

Recently I have been using the XYL's iPad as a video camera in front of a power meter in the garden by the antennas, with a Skype link back to the shack PC over wi-fi. Once the camera position and keeping it out of the sun were sorted out it worked very well for setting up levels.

73

John G3XDY

On 27/08/2020 14:33, Neil Smith G4DBN wrote:

Perfect for annoying the neighbours, plus the receive system is 40 metres away, and through two sets of windows, one of which doesn't open, so slightly awkward in this specific location.

Definitely a good way to tweak things though, as you don't have to look at the meter.  My 3400A even has a smoothed and buffered 0 to -1V DC output that is (sort-of) perfect for the job. The HP435B has a 0 to +1 V DC output which can be used  just the same.

I remember an audio tone SWR meter being used to tweak up the gamma match on a beam at a contest site sometime last century. It was set to lower SWR=higher frequency tone for some pseudopsychological reason.

Neil G4DBN

On 27/08/2020 14:30, Gordon REASON via groups.io wrote:

Sounds like a voltage controlled Audio Oscillator is needed ........... quite easy to do .

On 27 August 2020 at 13:38 "Dr. David Kirkby, Kirkby Microwave Ltd" <drkirkby@...> wrote:

On Thu, 27 Aug 2020 at 11:56, Neil Smith G4DBN < neil@...> wrote:

I like to view the meters remotely using binoculars when testing antennas.


I have never tried it, but a speaker driven by an audio oscillator with an output which changes volume and/or frequency, might be a way of adjusting something for minimum or maximum without actually looking at it. I would assume frequency would be more suitable than volume, but I don’t know. 


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