Quote:
Originally Posted by bandersen
Neither a VA 48 or 62 is a sweep generator though. Also you don't need a scope with a high bandwidth. What you need is one that can do X-Y mode.
I like the Wavetek 1002 or 1080/1 for a sweep gen and an HP 8657 RF gen for peaking coils and marker generation.
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No claim to either being a sweep generator. I went to the Sencore VA62 sales demo (free buffet!!), where the swept alignment feature was the show stealer. They had a Maggie color portable they let us mis-align, and they had it aligned in about 10 minutes with the VA62. Then we got to do the same, and had fun - again, fewer than 10-15 minutes to align. The VA48 used a similar system.
I agree it's not a
dedicated sweep gen - I used plenty of them in the Navy - HP, Century and Wavetek, but it's the best-all-around for TV use. As to the scope and X-Y mode, I dunno - the VA62 was paired with the 60MHz SC61, but a common 20MHz scope does fine. Trying to resolve on a cheapo 5MHz scope will drive you nuts. And what do you use for calibrated markers?
VA48 can be had for less than 50 bucks, and will do a lot more for a tech than a sweep gen. I have the HP 8601 and a Wavetek 185, but would never reach for them in servicing a set - see my prior comments on IF alignment necessity. In 25+ years of fixing sets,
I've never had a set that needed alignment. 1 exception - APC alignment, easy with the VA48.
Not saying that others haven't had such luck, but too many folks (newbies?) see a problem, and without troubleshooting, opt to align, when the problem is an open peaking coil, a shady cap, a missing bias voltage, AGC gone wonky, or a defective IF amp tube or transistor.
Blade track an ARC-51, align a APX-72 lid with a perfect bell curve, or align a 1030MHz preselector in a UPM-137, well, yes-I'd grab a sweep gen first. Of course, offer me an HP 8656B, and I'd probably sing it's praise - loved those sig gens I used in the Navy!