I'm sure this isn't the answer you want to hear, but ou won't gain anything by upscaling your SD source to 1080 60p. Be wary of internet alchemists and kahunas.

Your audio should all be 48Khz just for the sake of uniformity.

Your post indicates your DAR is 4:3. Your closest standard template is 640x480 with slight letterbox. A custom (exact) resolution would be 654x480.

So start with a very light Sharpen filter (0.100), the MainConcept AVC Internet 480p template, with a higher bitrate as shown, and you will have a "contemporary," internet-capable product with "maximum clarity," and understand that old DV tapes are what they are -- mediocre quality. Your teevee will do a better job of upscaling the viewed image than software, and that's a tested result.

You can also try it in Handbrake, which has a better decomb algorithm.

Thank you to EricLNZ and Musicvid for your replies--much appreciated! I look forward to testing out your suggestions...

Dear EricLNZ and Musicvid, I have finally had some time to experiment with rendering my old AVI files to MP4s using the recommendations you both suggested. It has made a big difference. They're much improved, so thank you! I have attached screenshots of the "Project Properties" for these videos, as well as the rendering template I used, which is a modified and re-named "Internet 480p 4:3" template. Look good to you? Please let me know if you have any further recommendations. Thanks again!

Please let me know if you have any further recommendations. 

You may get sharper results by setting the Deinterlace Method to "Interpolate" in Project Properties.

@Queenie

You may get sharper results by setting the Deinterlace Method to "Interpolate" in Project Properties.

+1

Also the average video bitrate of 2,000,000 bps is considerably lower than what I'd use. Try rendering a test to see if a higher bitrate gives any noticeable difference. I'd try doubling the max and average.

I'd render with free Voukoder (CRF 21 or similar) instead of the Mainconcept AVC encoder.

Dear Musicvid and EricLNZ, Thanks again for your prompt replies--much appreciated! I tried switching the "Deinterlace Method" from "Blend fields" to "Interpolate fields" in Project Properties, but my test video became more pixelated. I also tried raising the video bitrate to 10,000,000 maximum bps & 4,000,000 average bps, but didn't notice any real difference (except for an increased file size from 24.3 to 47.1 MB).

And fifonik, thank you for weighing in...

@Queenie

IMHO, the key to obtaining decent results for upload to YT or Vimeo is de-interlacing. When you de-interlace without doubling the frame rate, you are throwing away half of the temporal information in your media. Unfortunately, Vegas does not support frame doubling. Arguably, the best de-interlacer which supports frame doubling for such material is QTGMC, which is open-source and requires the use of Avisynth. Here are a couple of examples of the techniques that I have used. The first is an example of some Hi-8 footage and the second is an example of some DV footage with some stills animation.

https://vimeo.com/414645512

In both cases, they were first de-interlaced using QTGMC using frame doubling to 60P and then up-rezzed to 1280 x 720 using the Lanczos4 resizer. The resulting media files were then imported into Vegas for the addition of the blurred background and final render.

HappyOtterScripts https://tools4vegas.com/ supports such Avisynth processing, but is a paid app. Or you can spend some time and learn their use since they are open-source and freely available. If you're interested in trying such techniques on your own, the best source of help is the restoration sub-forum on VideoHelp. Here's the link. https://forum.videohelp.com/forums/41-Restoration Good luck.

Handbrake will also do frame doubling. I use it regularly to convert 50i to 50p. But you need to have the Filters/Deinterlace/Preset on BOB otherwise instead of different frames from the fields you get one field duplicated. Thanks to @Musicvid for helping me with this a few years ago.

Here's another example of de-interlacing using some of the advanced features of QTGMC for some extremely demanding footage--a B25 engine start.

https://vimeo.com/636837831/df988945aa

@wwaag  ... unfortunately, the link goes to a 'Sorry, we couldn't find that page' on Vimeo's website.

For deinterlacing my PAL videos inserted in a progessive double PAL project, I use the "Smart Adaptive (GPU only)" method. This gives the best results. In particular, video stabilization at the event level works best this way. However, so that VEGAS does not hang, it is absolutly necessary to set Dynamic RAM Preview max. to 0 MB. This is at least the case with my AMD cards. It is not necessary with other deinterlace methods.

For deinterlacing my PAL videos inserted in a progessive double PAL project, I use the "Smart Adaptive (GPU only)" method. This gives the best results. In particular, video stabilization at the event level works best this way. However, so that VEGAS does not hang, it is absolutly necessary to set Dynamic RAM Preview max. to 0 MB. This is at least the case with my AMD cards. It is not necessary with other deinterlace methods.

+1 Only with me no need to set DR Preview to 0 MB. I'm using a project setting of 1080p50 for older HDV (1080i50) footage, also with Smart Adaptive deinterlacing. Also with this setting it is possible to get great stabilisation results from interlaced footage with the Mercalli plugin.

I am now re-visiting this project & am using Sony Vegas Pro 14.0

FYI, no such product exists. VEGAS Pro 14 was released by Magix.

@Dexcon

Thanks. Here's the corrected link. https://vimeo.com/636837831/df988945aa

Thanks to all!

If the audio 'buzz' is embedded in the media file, try one of the usual suspect noise reduction plug-ins or stand-alone apps.
'Buzz' is a generalized term with different meanings to different folks. A 'buzz' to audio folks is usually equated to electro-magnetic type interference. OTOH, non-audio folks often confuse it with a 50/60 Hz hum (typical of a AC ground loop) which is dealt with differently.

Dear rraud, I just listened to the original source AVI file of this particular clip through headphones. Perhaps it is more of a hum, and it is intermittent. It was shot in Sofia, Bulgaria, where the standard voltage is 230 V, and the frequency is 50 Hz. (I used a voltage converter with my equipment in the larger cities and saved my batteries for work in the villages.) In the first render (another AVI), done in 2008 with Sony Vegas Pro 8.0, the hum is gone, but it is much more muted, and the highs & lows are very flat. This most recent render is an MP4, which I have uploaded to YouTube via this link:

I would be most grateful if you could take a listen. Perhaps you could tell if this "buzz" is "electro-magnetic interference" or a "AC ground loop hum". Then, of course, the next question is: What can I do, if anything, to fix it?! (Simple, detailed instructions and/or screenshots work best for me and would be most appreciated.) Again, thanks to all in advance!

Then, of course, the next question is: What can I do, if anything, to fix it?! (Simple, detailed instructions and/or screenshots work best for me and would be most appreciated.) Again, thanks to all in advance!

If this was shot using an early 2000's consumer camcorder, I'd say you got good audio -- declare victory and go home. It sounds fine to me. There are expensive tools you could employ to try to tweak it (ie, iZotope RX or similar) but I'm not sure anyone would hear a big difference. Try listening to this on a variety of devices and see if that affects how you perceive it.

All my video was shot with a Sony Digital Video Camera Recorder (model DCR-TRV17), purchased in June 2001 & top-notch back then... Thanks for your feedback, ALO!

... if this "buzz" is "electro-magnetic interference" or a "AC ground loop hum". 

The following image is a spectrogram view of the audio track (contrast/brightness/etc lifted to improve visibility of the frequencies):

The highlighted section at the bottom frequencies shows that there are changing in volume very low frequencies that could be causing the problem you are hearing. I think that it will be very easy to eliminate those frequencies by using the Track EQ FX in the track header and, with the Low Shelf setting, set the frequency field to 250 Hz (or what best suits while listening to the audio), the Gain to the minimum setting -Inf, and the Rolloff to the max setting of 24.

The blue in the Track FX window shows that with these settings there is a steep roll off and the bottom edge of the blue shows the frequencies that are eliminated. Of course, adjusting all three settings to fine tune is recommended

I hope that the above helps.

Aside from some infrasonic content (which is typically inaudible), I do not hear any objectionable hum, but as @Dexcon suggested, a high-pass filter can be applied... A low-pass filter could be applied as well since there is little frequency content above 8kHz or so.