Sig Gen replacment opinions

[AF7U]

Question/Poll
I am looking to upgrade my service bench signal generator. I am thinking along the lines of a signal/sweep generator. Which make/model seems to be popular with the techie folks? I'm talking RF service-design etc. I purchased my first spectrum analyzer/tracking gen and now realize I need a better general signal gen. (Probably cart b4 horse) I've been looking over HP's offerings along with Wavetek??? I am thinking used, not real vintage, new being off the charts for cost. I would like to keep my budget less two or three hundred. Thoughts? Feed back? Thanks in advance,
~Michael - AF7U

 

[WA0CBW]

It depends on what frequencies and how accurate you need to be but if you want to work on VHF and UHF equipment both transmit and receive a Communications Service Monitor might be what you want. These devices can be equipped with a spectrum analyzer, tracking generator, SINAD meter, power meter, tone generator, oscilloscope, and several other pieces of useful test equiment. Check EBAY for Communications Service monitor. Brands such as Motorola, General Dynamics, IFR, Hewlett Packard, Tektronix, Wavetek, and many others should show up.

Unfortunately $300 won't get you much. The equipment you are looking for will probably start at around $1,000 and up. Again it depends on the accuracy and frequency ranges you are looking for.
BB

 

[AF7U]

Thanks for the NFO, yes I have considered a Service Monitor and have fiddled with Cushman, CE-6 they seem to be the most affordable albeit somewhat dated. However I would rather have individual components, I don't need the ability to be portable, so I am evaluating individual pieces. My thinking primarily is work in IF, but looking for additional input. The Wavetek 164 operates to 30 MHz and it sweeps, that was *my* choice but was interested in others thinking.
73,
~Michael - AF7U

 

[zz0468]

...I would like to keep my budget less two or three hundred. Thoughts? Feed back?

Double your price range and you'll be able to find a nice used HP signal generator on eBay. The HP8640B is a decent model that's readily available, with lots of parts and information to keep it going.

 

[petnrdx]

I have had quite a few service monitors. (at least 10 I can remember )
My overall favorite is the Motorola 2600 series.
If you don't need tracking gen because you already have that, then the Motorola 2001 D series is a tried an true one. I have one still as my backup.
As others have posted, there are some REALLY good deals on the HP's that came out of cell service.
The only drawback on some of the HP's is they are large and heavy. But if you say you want it as a bench tool, I can't find a reason not to consider one. A friend of mine has one that was around a KiloBuck from one of the used equip suppliers a couple years ago. They are solid performing, just heavy.
I do mostly site work, so the slightly smaller, lighter 2600 fits me better.
I see a LOT of IFR 1200 series for sale at about 1Kbuck also a very good unit.
The only ones I hear bad things about are the IFR 1500, and of course the old Cushmans.
Cushmans are pretty old now. But if I needed something basic, and found one that worked for maybe 200 dollars, I might bite.
I still have a Wavtek as my 3rd. and "loaner". Works ok, but I would not want to use it for Public Safety stuff.
If you found one of those cheap, they are not that bad.
For bench if you are not used to the way any other "brand" works, those HP's look pretty good...

 

[AF7U]

I've been following a HP 3324A, on Ebay, up to 21MHz... I have also seen some 8640's now and then too... I worked a High End audio bench for nearly 25 some years back, then I bought Sound Technology, HP, and Tek. Now I'm semi retired and looking into some fun and games with RF. I would consider more $$$ if it was really necessary, I was just wondering what RF service techs were using today. PS, someone recommended WaveTek, I remember it from years ago, they are very solid units, or were in the 70's, any model numbers?
Thanks for the feedback, it is very appreciated.
~Michael

 

[zz0468]

...Now I'm semi retired and looking into some fun and games with RF. I would consider more $$$ if it was really necessary, I was just wondering what RF service techs were using today.

Maybe if you told us what exactly you're hoping to work on, we could give you better advice. There's a huge number of excellent surplus signal generators out there, but without knowing the frequency range of interest, stability and accuracy requirements, modulation requirements, and power levels, then we can't really make specific recommendations as to what would work.

 

[AF7U]

Well, I can appreciate wondering 'What's this guy going to do with it' sort of question. Here's my situation, I worked a bench for many years doing what I 'had' to do, business was business and you gotta' get things done, just like I suspect many of you folks. Now that things have slowed down (Think semi-retired) I want to do things that 'I' want to do. So it's difficult to really nail down. So my original question evolved around a curiosity of what do RF techs, in general, have on their service bench. After digesting some of the answers and thinking it over a bit, maybe I should be asking not what specific make & models, because that is so dependent on how much cash you have on hand, but more; what chores would you need a generator for in working with RF. For example, in the Hi-Fi work I did, we mainly used generators for alignment. Always Sound Technology, the ST-1000, along with producing RF between 89 and 106 for front-end work, it swept through the pass band of commercial FM receivers. Very specific and limited use. I hope this rambling isn't just clouding my first question, I just would like to take a peek into an RF techs daily routine needing a generator. So to that end, maybe I will re-frame my query and ask what specific tasks is your generator required to do during a typical work day. Unless your involved in R and D, I wouldn't *think* many shops would have multi-thousand dollar pieces. However I could be wrong. Maybe the majority of benches do have an expensive RF producing extravaganza on their work bench. My thinking is knowing what the average Joe's requirements are, I can extrapolate what I need from there. (or maybe I'm full of BS and don't have a clue what I'm talking about. hahaha)
Thanks for everyone's time thus far, it really is greatly appreciated~!~
~Michael

 

[zz0468]

My bench is hardly the average Joe's bench, so maybe I shouldn't be the one giving advice here - my test bench has measurement capability well into the millimeter range. But I will, anyway.

First, that HP you're looking at that goes up to 21 MHz won't be good enough. You're going to need capability that goes higher. Just how high is up to you. But if you want to work on, say, a general coverage HF receiver, you want something that at least makes it to 30 MHz. If you want to work on scanners, especially something that goes to 800 MHz, then a generator that will go to 1000 MHz is what you'll want to be looking at. If you decide you want to work on transmitters as well, then maybe a service monitor is what you want.

In my mind, a signal generator should be capable of generating a signal of as high, or higher, quality than the receiver I'm working on is going to be receiving off the air. That means stable, clean, accurate and of known frequency, and accurate amplitude. You should be able to apply modulation, either a tone or external audio source.

It should have a 10 MHz reference and the ability to either source that reference to other equipment, or use an external reference from other equipment - at some point frequency accuracy may be important to you. All my equipment is referenced to a common GPS disciplined rubidium oscillator. It'll make you crazy if the signal generator says 10.0000 MHz, your counter says 9.9999978 MHz, and the receiver you're testing says 10.003 MHz.

All that translates to $. You really need to decide what sort of use it's going to be put to before you decide. Even if the current use is as vague as 'building block for a more capable test bench', then that would dictate that you buy more a more capable generator than you think you need right now. Anything less will end up getting thrown out the window in frustration when you find that it's not stable, or it doesn't go high enough, or it's so full of spurs that you don't know what the real frequency is.

 

[petnrdx]

Sounds like you and I are at a similar stage in life.
I am retired, and now since the narrow banding is done, "retired" again from that "part time" work.
Now working stuff for friends, and the fun of it.
Or things that I just find interesting.
I started with the old Motorola 1034 ( Measurements brand ) sig gen and a Singer-Gertsch freq meter.
As for service monitors that I have owned:
Motorola S1327b ( a few of them. They seemed to have common problems that caused them to die)
Mot. 1200
Wavetek 3000b and 2100 still have the 2100 as a "loaner"
IFR1000
Motorola 2001 a, 2001b, and 2001 d series. Still have a D model for backup
Motorola R2600
Others that I have used that belonged to others or employers
Cushman CE4, CE 4, CE6, CE31, and CE 50
IFR COM 120 ( I think ) 1200s, 1500, and something like 500 maybe. Memory is bad.
Several peoples various HP's whose numbers I can't keep straight.
As a bench service monitor I really like the Motorola R2001 D series. But while versions have sweep gen they don't have tracking generator.
As a field instrument for nearly all things I love my R2600. Other people I have worked with and for like the IFR1200super S. Both are really similar wonderful trustworthy instruments.
If time is money and you are trying to make a profit, or just time has a big value, those to are my highest recommended units.
I had the Wavetek 3000b and only traded it off when I added the R2600. I worked great, but didn't have all the field work features I needed.
The little Wavetek 2100 is about the same. Seems to be a good basic unit. I like to be able to see waveforms on the scope which it doesn't have. If you already have an O'scope you can use with a simple service monitor, you can save a lot of money by buying a lower tier unit. Takes more time, but if you know how to do those things, and you have more time than money, it is a thought to consider.
All this older stuff has some often know issue.
I have heard a lot of people say to avoid the IFR1500 now that they are getting old.
Never heard anything bad about the IFR1200.
The displays on all this stuff seems to be a limitation. Hard to find some of the parts if they die.
A couple ham friends have purchased the HP8935 ( I am about 90 percent sure that is the number)
If my R2600 died now, I would likely buy one of the HP's just because they look to me to be the most affordable. I find their operation a bit clumsy since I am used to G-D operating. And that 8935 is HEAVY.
But it does pretty much everything I want.
Most of the shops I have been into the last decade seem to have the Aeroflex (IFR) units of various models.
And Anritsu would be the second brand I have seen most often.
Since I am used to the R2600 series which was made by General-Dynamics, I probably would have bought one of theirs if mine died while I was still working.

 

[AF7U]

First, thanks zz for taking the time to articulate your thoughts so well, actually to everyone for answering. To zz; everything made complete sense to me. Yes, I would certainly think I would be needing more than 21MHz, I should have thought of that right off but thanks for point it out. I think I have a better idea of what I'm looking for. I may post back some particulars once I zero in on something. The comments on frequency disciplined oscillators brings to mind an article I've been following on the evolution of SDR, someone is using the Jupiter-T as an interface for frequency stability. I would love to learn more about such a fascinating subject, that is on my list of things to dabble in. I understand your thinking, it would be outstanding to have the stability referenced to a standard such as GPS so everyone is playing on the same page. Thanks again for pointing out some very interesting points. I will definitely consider your thoughts as I move forward, I see I may need to recalibrate my search for equipment. I see your in California? I'm up here in the great Pacific Northwest. Sort of cool and rainy today.

 

[AF7U]

petnrdx, I just saw your reply. Good NFO, I will read it over, unfortunately I need to run to PDX for some shopping. They have a Tektronix Museum up there and they are selling some 'extra' goodies. Be back this evening.
~Michael

 

[petnrdx]

I have four Tek products I still use. Good stuff. Used to pick up good deals, and spare parts / accessories at Sea-Pac. I bet their museum is cool...

 

[AF7U]

I'm back, and the museum was VERY cool... I had a great time, what a fantastic collection of vintage Tek gear. I had a chance to play with my very first scope, a 545... (High school, circ. 1968) a real boat anchor but it was remarkably clean and worked flawlessly. (They told me they clean units with 'Simple Green' and it works like a charm, Hmm hadn't thought of that) The room was full of Tek blue, truly a wonderful visit. I had quick visited earlier but this visit I took some time to visit with the staff, seems many are hams. I picked up some goodies on my earlier trek, a 7104 one Gig main frame, with the apropos modules. It was interesting seeing minor wave anomalies that I'd missed on a lower BW scope. The 7B92A, dual time-base plug-in, I purchased was a tiny bit microphonic and rather than dig into it myself, and being it was still under their guarantee, so I returned it to be evaluated. I'm sure it was just contaminants on contacts but I thought it best to let them square it up. I also brought up a 7L13 for show and tell which they had asked to see on an earlier visit. They only display 'working' units and so far they hadn't a working 7L13 for display. BTW, the group is looking for a 570 if anyone has one collecting dust. It is a real hole in the 50's collection and what a GREAT cause. I found one at the local community college but it would be a nightmare of red tape to get it out of their storage room.

So... regarding your earlier response... Thanks for the detailed model numbers. I spent an hour or two reviewing all the units you spoke of, although I wouldn't rule out a GP service monitor, I'm thinking I'll grab a dedicated signal/sweep generator. At least that's today's thinking, the NFO you posted was interesting and monetarily *very* interesting. Compared to some signal generators, I could get a SM for the price of a signal gen. Anyway, lots to think over, and I need to get something pretty soon. Thanks out to everyone for the feedback, it is always appreciated.
73,
~Michael