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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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27th Jun 2020, 2:40 pm | #1 |
Octode
Join Date: Jul 2017
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AM/FM Signal Generators With Sweep (Wobbulator) Function
I have been doing some research into what equipment would be suitable for 'visually' aligning FM radios and have decided to put together a list to help those who are thinking about obtaining such equipment.
The focus of this list is primarily focused on equipment that has an internal sweep/wobbulator function for FM IFs. Even better if they can also sweep AM IFs! The list should not be considered comprehensive. The equipment below is what I have found mentioned in this forum over the years. If you have anything to add (information, new models, service date etc.) please let me know! To be researched: Telonic 1204a, 1234a, 1205a. Wavetek 2000, 2001. I'm not sure if these are suitable for RF applications. AM/FM Signal Generators With Sweep (Wobbulator) Function Philips PM5324 (1973): • AM/FM signal generator plus sweep function. • Sweep function covers a variety of AM/FM IF frequencies. • 100KHz – 110MHz range. • No internal marker facility. • Service manual available. • Solid state (integrated circuits and transistors). • 5 Kg. Philips PM5326 (1979): • AM/FM signal generator plus sweep function. • Sweep function covers a variety of AM/FM IF frequencies. • 100KHz – 125MHz range. • Internal marker facility. • LED display. • Service manual available. • Solid state (integrated circuits and transistors). • 6.5 Kg HP8601A (1980): • AM/FM signal generator plus sweep function. • Sweep function covers a variety of AM/FM IF frequencies. • 100KHz – 110MHz range. • No marker facility • Service manual available. • Solid state (integrated circuits and transistors). • 9.5 Kg Marconi TF2008 (1972): • AM/FM signal generator plus sweep function. • Sweep function covers a variety of AM/FM IF frequencies. • 10KHz – 510MHz range. • Internal marker facility. • Service manual available. • Solid state (integrated circuits and transistors). • 21 Kg (!) Taylor 62A MkII (Late 1960’s): • AM/FM signal generator plus sweep function. • Sweep function covers a variety of AM/FM IF frequencies. (Might just sweep FM only? Output too high to cover AM IF.) • 4MHz – 120MHz range. • No marker facility. • Service manual available. • Uses three valves and a solid state rectifier. • 9.5 Kg Taylor 62A MkI (1960): • Not a great deal known. Possibly very similar to the MkII? Advance 63a (date unknown): • AM/FM signal generator plus FM sweep function. • 7.5MHz – 230MHz range. • Not a great deal known. • No service manual available. • No marker facility. • Valve based. • Not to be confused with the ‘Advanced 63’, which is similar to the ‘63a’ but does not have a sweep function. Advance SG63E & SG63F (1968): • AM/FM signal generator plus FM sweep function. • 4MHz – 230MHz range. • Both models are electrically similar. • Service manual available. • Hybrid design. One valve and one transistor plus various diodes. • 12.2 Kg |
27th Jun 2020, 5:50 pm | #2 |
Octode
Join Date: Sep 2017
Location: Bristol, UK.
Posts: 1,642
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Might be useful to include the Marconi TF 995A and TF 995B generators. There are still a few around and in use (I've got a TF 995B/2 myself). I know there are people on here who know quite a bit about them (not me, I hasten to add - though I do have some manuals).
Mike |
27th Jun 2020, 6:29 pm | #3 |
Rest in Peace
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
There's also the fairly famous Raymond Haigh design from Radio Bygones discussed in this thread..
Cheers, Frank |
27th Jun 2020, 8:34 pm | #4 |
Hexode
Join Date: Mar 2014
Location: Peacehaven, East Sussex, UK.
Posts: 278
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
I'd like to add the Radiometer Re101, I have 2 of these the second of which was rather a bargain. AM/FM with internal or external modulation plus sweep. LED frequency readout.
the service manual is also available but too big to attach here |
27th Jun 2020, 8:54 pm | #5 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Marconi's TF2002 signal generators can be electronically swept by an external source (e.g. oscilloscope timebase) over a limited range on their higher frequency bands (100kHz-72MHz -A version, 32kHz-88MHz -B version). The manual concedes that they can be swept over a somewhat wider range on their 100kHz-320kHz and 320kHz-1MHz bands (i.e. the common IF range for many radios) with reduced linearity, so that a reasonable spread of IF spectrum can be displayed ranging from 5kHz at 100kHz to 90kHz at 1MHz. The manual gives details of a straightforward external interface to the DC-coupled shift circuitry.
Not quite the plug'n'play convenience of a dedicated internally-swept machine, but a potentially useful additional feature. Note that any version of this bulky and heavy device is 40-55 years old by now and may well have several faults- if you find working through a succession of finicky-to-sort problems satisfying, then fair enough! |
27th Jun 2020, 10:06 pm | #6 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
There were professional wobulators built for TV work (manufacturer use) made by Samwell and Hutton (I had two years ago) and I guess they did an FM one as well. Big, monstrous devices, built in CRTs etc..
Actually I want a wobulator for FM, and was offered two here some months ago, but I concluded they were too big for the available space, so I had to back out. Is there nothing available for VHF/FM in "modern" size and construction? Les. |
28th Jun 2020, 9:26 am | #7 |
Moderator
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
The HP8601A is quite small.
David
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28th Jun 2020, 5:52 pm | #8 |
Heptode
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Location: Heysham, Lancashire, UK.
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
The Philips PM5324 is roughly a 28 x 28cm footprint 18cm high.
Stuart |
28th Jun 2020, 6:28 pm | #9 |
Heptode
Join Date: Feb 2006
Location: Marlborough, Wiltshire, UK.
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
For a one-off job and not wanting another instrument, I ended up building a wobulator to check FM radios using an arduino board with a dds add-on. Surprisingly straightforward to do, even for an Arduino novice and a good lockdown project. Very easy to change parameters except amplitude but no nice screening etc (a biscuit tin worked well enough).. Of course you have the hardware at the end to reuse on something else.
Ken |
28th Jun 2020, 7:23 pm | #10 |
Octode
Join Date: Jul 2017
Location: Newcastle Upon Tyne, Tyne & Wear, UK.
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Thanks for the additional pointers. The Radiometer RE101 has been added to the list. It looks to be an excellent piece of kit! Does anybody know where I could find one?
At the moment I will stick to gear that has a built in sweep facility. I would like to also compile a list of standalone signal generators. Does anybody know what sweepers were in common use in the servicing trade throughout the 1950's - 1990's? Service manuals never suggest suitable equipment. Last edited by OldTechFan96; 28th Jun 2020 at 7:35 pm. |
28th Jun 2020, 8:30 pm | #11 |
Octode
Join Date: Jul 2009
Location: Cheshire, UK.
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
The HP 8601A dates back to at least 1969, not sure when it was discontinued but I have seen one with a 1982 date code. The 8600A digital marker could be used with it too, only problem is there doesn't seem to many around.
David |
29th Jun 2020, 12:07 am | #12 |
Nonode
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Hi!
I'm fairly sure the Heathkit HFW–1 is suitable for FM alignment work, but prices on these are starting to reach "Heathkit–foolery" levels, and also, every one I've seen has been made with the dreaded brown and black Hunts capacitors! There's a full assembly manual online but it is very, very faint, so you do need good eyes to read it! Do be careful with the tags and wiring to the proprietory Heathkit controlled main Inductor (they called it an "Incredi–ductor(!)") – if you have to repair one of these units, the leadout wires are very, very fragile! Chris Williams
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29th Jun 2020, 12:31 am | #13 |
Octode
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Thanks for the heads up about the Heathkit HFW–1, I'll look into it soon.
I agree about the prices such Heathkit (and other makes) go for online. Could anybody hazard a guess as to why this is? |
29th Jun 2020, 8:55 am | #14 |
Moderator
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
There was a network analyser (to 110MHz) built around the HP 8601A sweeper and a lot of 8601s went into these systems, but the 8601 was a useful little generator with a comprehensive output attenuator and could do AM and FM so it lived on well beyond the other boxes of the network analyser.
They got used in HP's factory test systems as a lower cost signal source. Plenty sold in the US, but not that many over here, so they're fairly uncommon on the UK market. Worth grabbing one if you see one at a sensible price. THey use a wide-range pulse-count frequency discriminator in a feedback loop to linearise the tuning. The tuning knob runs a gearbox into a ten-turn pot. THey're not the ultimate in frequency stability, nor in phase noise, but they are quick and useful. David
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30th Jun 2020, 9:28 pm | #15 |
Octode
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Location: Newcastle Upon Tyne, Tyne & Wear, UK.
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
I have looked into the Heathkit HFW–1 and I think it is suitable for FM alignment.
The HP and Marconi gear really suits the bill. My concern would be repair-ability and whether it uses hard to find proprietary parts. |
1st Jul 2020, 1:24 pm | #16 |
Tetrode
Join Date: Jan 2019
Location: Toulouse, France
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Hi ,
For the HP8601A ,except for RF output amplifier IC, others are mainly standard components or easy to replace by equivalent. This my preferred generation of HP equipment because is quite easy to repair : good documentation, reliable, easy access to components, large community on Internet using and repairing it,no software, if required specific components possible to buy ( some time a little expensive...), and when we repair it is very interesting to understand the design with elementary functions. HP generation before was using tubes, and after less reliable ( depending on series) and to much SW and specific ICs. Jean-Louis |
2nd Jul 2020, 5:36 pm | #17 |
Octode
Join Date: Jan 2009
Location: Falmouth, Cornwall, UK.
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Just for info, both versions of the 62A do sweep & CW and sweep & AM
sorry for quality, not my scans
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2nd Jul 2020, 9:32 pm | #18 |
Hexode
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Another vote for the HP8601A, easy to use apart from being a little difficult to set the exact frequency with the 10 turn crank unless you parallel the output with a frequency counter. There is an aux output you can use for this. No software so it's fixable at home. Someone is reproducing the output amplifier module, I forget who but they were findable on Google.
Mark |
2nd Jul 2020, 9:51 pm | #19 | |
Octode
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Quote:
It is a shame they don't cover the MW/LW bands as they would be a handy AM+FM sweeper and signal generator. |
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3rd Jul 2020, 2:20 pm | #20 |
Octode
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Re: AM/FM Signal Generators With Sweep (Wobbulator) Function
Advanced 63:
Looking at the manual supplied by WaveyDipole, I have came to the conclusion that the Advanced 63 has an in built FM sweeper and therefore can be used for FM alignment. The sweep output comes from a socket marked 'FM2'. The 63A must be a minor revision of the 63. |