Re: Marconi 6960B


Robin Szemeti - G1YFG
 

I have a HP435 with a HP8484 head ...   the HP reference source and the Marconi source measure within a needles width of each other, so I am assuming they are pretty good. 

If you can just try the head on your meter and let me know if you get any sensible readings, I think that will be enough ... I just need to know if it is working really.  And maybe also  the other way round ... try your head on my meter,  I can see the chopper drive and voltages look correct to the head look correct, I suspect the measurement A-D in the Marconi is sub-optimal.

I'm in Bewdley, north of Worcester, but I can shuck them at the UPS driver easily enough.


On Tue, 3 Nov 2020 at 10:39, Paul G8KFW <paul@...> wrote:

Hi Robin

 

Actually I don’t think I have actually measured the signals on the head  probably put them on a scope in my early days  what HP power meter set up do you have ?

Sorry I don’t have your location

 

Regards Paul  07719 208048


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Robin Szemeti - G1YFG
Sent: 03 November 2020 02:05
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Marconi 6960B

 

That would be perfect.   

 

I've measured various signals and voltages, and the head appears to be down in sensitivity somewhat, but if I provide it with a slightly higher cal signal to compensate, and deliver the correct signal level at the various stages, it still fails to cal ... it would be nice to figure out which bits are knick-kancked!

 

At least my HP meter works!

 

On Tue, 3 Nov 2020 at 00:13, Paul G8KFW <paul@...> wrote:

Hi robin

I live in West Sussex on the south coast UK  

I will check out but I should have 2 off Marconi 6960 B providing they are working sorry neither is for sale

As they are part of a proposed Calibration rig

 

But I can check your head and meter out for you and they can be checked agenised a Marconi or a HP head

 

Regards Paul


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Robin Szemeti - G1YFG
Sent: 02 November 2020 23:59
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Marconi 6960B

 

I'm having trouble deciding which is the problem item out of my Marconi 6960B and measuring head ...

 

I bought them in differing places,  the head was supposed to be a good 'un, the meter was supposed to be faulty ... I am unsure if either statement is correct.  I get 0.000 with the source off .. and -0.24 mW with the source on ... negative ... almost all the "dead" heads I have seen in the past have simply failed to respond if blown, not go negative ...

 

Does anyone have a known working 6960B?  Could I send you my measuring head to check?

 

Best regards,

Robin Szemeti

Redpoint Consulting Limited 

E: robin@... 

T: +44 (0) 1299 405028 

M: +44 (0) 7971 883371 

Thank you. 


Robin Szemeti - G1YFG

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Paul Bicknell G8KFW   South Coast UK


Robin Szemeti - G1YFG

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--
Paul Bicknell G8KFW   South Coast UK


--
Robin Szemeti - G1YFG

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