Spectrum Analyser - UK Vintage Radio Repair and Restoration Discussion Forum

ParcGwyn · 18th Mar 2019, 7:58 pm

Managed to pick up an HP8557A Spectrum Analyser with an HP184A display unit at Wythall Radio Rally for a very reasonable price, I was assured by the seller it was working but was unable to try it. Upon getting home I have had a play with it and it appears to be in excellent working order. It even came with the manual for the 8557A plugin. The plugin does not have a probe power socket fitted but a much more useful local oscillator output, I hope to use this output to feed a crude homemade tracking generator.

Dave

GW7ONS

MrBungle · 18th Mar 2019, 8:09 pm

That's a pretty good win. I don't think anything I've got from a radio rally has worked even if assured. A lot of the time it tends to explode after a couple of minutes

chriswood1900 · 18th Mar 2019, 9:32 pm

Its always the RIFAs that get you!

Andrew2 · 19th Mar 2019, 9:59 am

A lovely scope. I used to have a 180 years ago and the quality of the display was second to none - bright, sharp as a pin and easily visible at even the highest speeds. I think HP used one of their posh tubes in it.

Humber888 · 19th Mar 2019, 10:59 am

Odd, I thought I had posted a reply just now, but it's not showing. Anyway the gist was that the HP184A mainframe is a storage version of the 180 series of 'scopes. So, I hope yours is not suffering from screen burn due to the brightness being turned up too much in 'normal' mode. The display should really always be used in storage or variable persistence modes. There have been previous threads on the 184A and how it should be driven by others more qualified than me. You can get some nice plug-ins for the mainframe as well - anything up to 100MHz, 4-channel Y amps and corresponding dual timebases.

I expect the carrying handle has broken as the plastic hardened. It may have been replaced by one with an internal steel strap if you are lucky.

Mike

Skywave · 19th Mar 2019, 1:03 pm

Quote:

Originally Posted by Andrew2

A lovely scope. I used to have a 180 years ago and the quality of the display was second to none - bright, sharp as a pin and easily visible at even the highest speeds. I think HP used one of their posh tubes in it.

All of which matches my experience. Unfortunately, I had to part company with mine when the EHT module failed: suspect defective EHT transformer.

Al.

MrBungle · 19th Mar 2019, 1:21 pm

Wasn't it the same tubes as the 1740 series as well?

I had a 1740 for a while and that was rather nice, apart from the flood gun illumination. I couldn't get on with that.

ParcGwyn · 19th Mar 2019, 1:50 pm

The tube appears fine and you're right Mike the handle is broken.

Dave
GW7 ONS

avocollector · 23rd Mar 2019, 10:53 pm

Great - if I had a cent for every time I was assured an item was working despite not being able to try it, I'd be laughing. So it's nice to know the assurance is not always false. Mind you part of the fun is getting it going regardless.

MrBungle · 24th Mar 2019, 12:26 am

It’s ok until you’ve got four broken ham fest Tektronix scopes in the cupboard and no time to do anything about it

I may have to pass these on at some point.

Radio Wrangler · 24th Mar 2019, 3:54 am

You can get sampling scope plug-ins to 1GHz and beyond.

a TDR.

There's even a logic analyser.

David

Humber888 · 24th Mar 2019, 11:51 am

Yes I forgot the sampling plug-ins, although they are pretty rare. I have got the logic analyser plug-in (1601A). It's very basic - 12 bit and only able to display 1s and 0s, not octal or hex. The probes are the most fragile bit as usual.

18th Mar 2019, 7:58 pm	#1
ParcGwyn Hexode Join Date: Jun 2005 Location: Aberystwyth, Wales, UK. Posts: 358	Spectrum Analyser Managed to pick up an HP8557A Spectrum Analyser with an HP184A display unit at Wythall Radio Rally for a very reasonable price, I was assured by the seller it was working but was unable to try it. Upon getting home I have had a play with it and it appears to be in excellent working order. It even came with the manual for the 8557A plugin. The plugin does not have a probe power socket fitted but a much more useful local oscillator output, I hope to use this output to feed a crude homemade tracking generator. Dave GW7ONS Attached Thumbnails

18th Mar 2019, 8:09 pm	#2
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Spectrum Analyser That's a pretty good win. I don't think anything I've got from a radio rally has worked even if assured. A lot of the time it tends to explode after a couple of minutes

18th Mar 2019, 9:32 pm	#3
chriswood1900 Octode Join Date: Jan 2007 Location: Dorridge, West Midlands, UK. Posts: 1,479	Re: Spectrum Analyser Its always the RIFAs that get you!

19th Mar 2019, 9:59 am	#4
Andrew2 Nonode Join Date: Mar 2010 Location: Dukinfield, Cheshire, UK. Posts: 2,036	Re: Spectrum Analyser A lovely scope. I used to have a 180 years ago and the quality of the display was second to none - bright, sharp as a pin and easily visible at even the highest speeds. I think HP used one of their posh tubes in it. __________________ Andy G1HBE.

19th Mar 2019, 10:59 am	#5
Humber888 Heptode Join Date: Jul 2012 Location: Bromley, London, UK. Posts: 702	Re: Spectrum Analyser Odd, I thought I had posted a reply just now, but it's not showing. Anyway the gist was that the HP184A mainframe is a storage version of the 180 series of 'scopes. So, I hope yours is not suffering from screen burn due to the brightness being turned up too much in 'normal' mode. The display should really always be used in storage or variable persistence modes. There have been previous threads on the 184A and how it should be driven by others more qualified than me. You can get some nice plug-ins for the mainframe as well - anything up to 100MHz, 4-channel Y amps and corresponding dual timebases. I expect the carrying handle has broken as the plastic hardened. It may have been replaced by one with an internal steel strap if you are lucky. Mike

19th Mar 2019, 1:21 pm	#7
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Spectrum Analyser Wasn't it the same tubes as the 1740 series as well? I had a 1740 for a while and that was rather nice, apart from the flood gun illumination. I couldn't get on with that.

19th Mar 2019, 1:50 pm	#8
ParcGwyn Hexode Join Date: Jun 2005 Location: Aberystwyth, Wales, UK. Posts: 358	Re: Spectrum Analyser The tube appears fine and you're right Mike the handle is broken. Dave GW7 ONS

23rd Mar 2019, 10:53 pm	#9
avocollector Heptode Join Date: Jul 2010 Location: Wellington, New Zealand. Posts: 653	Re: Spectrum Analyser Great - if I had a cent for every time I was assured an item was working despite not being able to try it, I'd be laughing. So it's nice to know the assurance is not always false. Mind you part of the fun is getting it going regardless.

24th Mar 2019, 12:26 am	#10
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Spectrum Analyser It’s ok until you’ve got four broken ham fest Tektronix scopes in the cupboard and no time to do anything about it I may have to pass these on at some point.

24th Mar 2019, 3:54 am	#11
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,858	Re: Spectrum Analyser You can get sampling scope plug-ins to 1GHz and beyond. a TDR. There's even a logic analyser. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

24th Mar 2019, 11:51 am	#12
Humber888 Heptode Join Date: Jul 2012 Location: Bromley, London, UK. Posts: 702	Re: Spectrum Analyser Yes I forgot the sampling plug-ins, although they are pretty rare. I have got the logic analyser plug-in (1601A). It's very basic - 12 bit and only able to display 1s and 0s, not octal or hex. The probes are the most fragile bit as usual.