Question's About a RF SIGNAL GENERATOR

[n8yhy]

Hello To The Group

 I am searching for a RF signal Generator to purchase and was wondering about the Tenma 72-585 RF GENERATOR but I don't know anything about it so was wondering what some of the more experienced gentleman out there thought about the TENMA 72-585...And if this turns out not being worth while would any one recommend another one to get that is in a reasonable price range...I placed a link below that show's the Tenma 72-585 RF GENERATOR...Thanks to everyone for taking the time to review my question here..Thanks Chris N8YHY

http://site.mcminone.com/product.asp?catalog%5Fname=MCMProducts&product%5Fid=72%2D585

[WV Hoopie]

Hello Chris,

The answer might depend on how you are going to use the sig-gen. I'm sure the more experienced will chime in and recommend one that will give lots of bang for the buck. My shack has an old URM-25D, ($50) that gets the job done. I think as of late test equipment has been selling for bargin prices. Something newer with more whistles and bells, sand state, wud be nice for Christmas,

wd8kdg
Craig

[WA1GFZ]

The HP8640B is one of the best made. I found one of mine for $100 that took 1/2 hour to repair. bama has all the books. the urm25 is a drift of matic and does not compare to the hP. You will spend a lot of money beating the performance of a 8640B. I has a cavity oscillator running at 250 to 500 MHz. ECL dividers down to 500 KHz. It just hits 455 KHz. built in modulation and accurate attenuator and power output. $300 is a normal price.

[W3NP]

You might also look into the Fluke 6060A or 6061A. I have both of them and after using URM-25D's and F's ....yes they drift bad, and the even worse B&K, Heath, Eico, etc,  analog pointer dial type of Generators, it is nice to set the freq, level, modulation and have it be dead on and STAY there.

The Flukes and the above mentioned HP can oft be found on Ebay for a decent price....maybe not a lot more than the one you are considering. I know nothing about the Tenma, but it looks an awful lot lot the ones I used to struggle with.

If you go the used high quality route...Fluke or HP....try and get one that has the High Stability (ovenized timebase) option.

[W2VW]

The HP8640B is one of the best made. I found one of mine for $100 that took 1/2 hour to repair. bama has all the books. the urm25 is a drift of matic and does not compare to the hP. You will spend a lot of money beating the performance of a 8640B. I has a cavity oscillator running at 250 to 500 MHz. ECL dividers down to 500 KHz. It just hits 455 KHz. built in modulation and accurate attenuator and power output. $300 is a normal price.

Hi Frank,

   How does the external mudulation input perform. Can it do 100% postive?

[w3jn]

Chris, that's about as bargain basement a generator as you'll find.  It's gonna drift and you'll need a freq counter to find where you're at.

I have several synthisized sig gens around here, in no case have I paid over $100.  They are MUCH easier to align receivers with, just punch in the freq and go.

You can get a toob equivalent of that sig gen at any hamfest for $2.  Well worth it and about equivalent performance if all yo're gonna do is align a receiver once in a blue moon.  But if you're serious about repairing stuff, go with a synthesized gen or as Frank said a HP8640.  Some models of the 8640 have an external input to the freq counter, that's really handy.  The 8640 is prolly THE standard for a low-noise generator.

Again, depends very much on what you're gonna use it for and how much you'll use it.

73 John

[WA1GFZ]

Dave,
I'm not sure but I can peg the mod meter. I thinks it goes into distortion at 100 %. My units have the variable frequency audio section. An external double balanced mixer would allow anything you want.
There is a cool test set up for measuring phase noise in the manual.
The flukes are nice but they are synthesizers so not as clean as the cavity in the 8640B. The 8640B has a frequency lock loop function that holds the frequency for a long time once it has been warmed up.

[W3NP]

If I were in the market for a good sig gen....I would jump on this at the buy it now price....not much more than the "big dial" thing you were considering.

You will like it...I had one of these once too. I still like my Flukes but didn't see any deals on them.

http://cgi.ebay.com/HP-8640B-V3-signal-generator-5-to-550-Mhz-Works-well_W0QQitemZ7573917992QQcategoryZ97198QQrdZ1QQcmdZViewItem

[WA1GFZ]

I have 4 hp 8640Bs 1 hanger queen one needs to be fixed and 2 operational.
Modular construction makes them easy to repair.
The fluke is a nice gen but they go for good bucks and may not be as clean.
The 8640 is a simple clean design. The only problem with them is the gears in the older units. some smart guy will find replacements ant they will live for ever.
The gears effect the FM modulation control so...

[W3NP]

Too late....someone bought it already.

If I were in the market for a good sig gen....I would jump on this at the buy it now price....not much more than the "big dial" thing you were considering.

You will like it...I had one of these once too. I still like my Flukes but didn't see any deals on them.

http://cgi.ebay.com/HP-8640B-V3-signal-generator-5-to-550-Mhz-Works-well_W0QQitemZ7573917992QQcategoryZ97198QQrdZ1QQcmdZViewItem

[WA2TTP Steve]

I have an HP-8640 with the variable modulation frequency option. The audio frequency dial markings on mine are barely readable . Does anybody have a spare one of these dials they would be willing to part with?

Steve
srosenb2@nycap.rr.com