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AE1PT
10-04-2012, 07:38 PM
I have come to the conclusion that aligning IF stages by VTVM peak is less than optimal--especially for boatanchor communications receivers. Just because it peaked does not mean that the damn thing is centered. With that thought in mind I am thinking sweep generator with internal markers, or an external marker generator.

There are a couple ways to go about this from the marker perspective. I can inject an isolated signal into the output of the sweep with my Wavetec function generator. The "marker" or actually a ripple along the top of the demodulated sweep waveform can then be observed. One merely moves the second generator frequency (monitoring on the frequency counter) from one side of the top to the other noting the frequency of the top skirt edges. Dirty, but it will do the job.

I would like something a bit more elegant, like the clean markers I used to see on my B&K 415 back in the day. There seem to be a shitload of sweep generators out there, but not really anything targeted to communications receivers. Got any thoughts?

P.S. I want to keep the budget on this below $250...

WTKX
10-04-2012, 08:43 PM
Used to use an old Eico that had an external audio input so I could decide what freq to modulate with, and get "sidebands" where I wanted 'em. There may be a kit out there that will do that, but looky what I found on Amazon. Hell, I might get one of these myself...

http://www.amazon.com/Parts-Express-RF-Signal-Generator/dp/B0002KR9OS/ref=pd_sxp_f_pt

I have purchased a bunch of goodies from Parts Express via Amazon. Good stuff. :yes:

N8YX
10-05-2012, 08:23 AM
Ebay's yer buddy (again):

http://www.ebay.com/itm/HP-8601A-Signal-and-Sweep-Generator-100-KHz-to-110-MHz-/320994260555?pt=LH_DefaultDomain_0&hash=item4abcbfb64b

I would consider one of their synthesized units too but most are going for $500 and up. A buddy lucked out at Breezeshooters a couple years ago and got a later-model synthesized HP SSG for $50.

K6BSO
10-05-2012, 08:42 AM
There was an article about building a sweep generator in this month's copy of QEX. If you're a member, you may be able to download an electronic copy from the ARRL web site.

AE1PT
10-05-2012, 10:32 AM
Ebay's yer buddy (again):

http://www.ebay.com/itm/HP-8601A-Signal-and-Sweep-Generator-100-KHz-to-110-MHz-/320994260555?pt=LH_DefaultDomain_0&hash=item4abcbfb64b

I would consider one of their synthesized units too but most are going for $500 and up. A buddy lucked out at Breezeshooters a couple years ago and got a later-model synthesized HP SSG for $50.

Looked at that one yesterday. It's missing the tips to the levers--something that at that price point a lot nicer examples have gone on the Bay for the same or less. But the idea of an 8601 is a candidate.

There is also an older BK 3030, and quite a few nice BK 4017A units. The prices on the latter are really variable--I will wait for the last couple seconds and see what I can swoop in and bag... :snicker: