Weak Wi-Fi drags down DSL? Try moving the modem

Q. My Verizon DSL modem-router combo doesn't offer enough Wi-Fi range. Can I replace that with a better model?

A. Yes, although Verizon doesn't make that option at all clear. Its support site is silent on the subject, and spokesman Harry Mitchell had no advice to offer on it either.

But if you're not satisfied with the reach of a Verizon-issued "gateway" — in this reader's case, an older D-Link model— and you can't persuade the company to ship you a new model, you can indeed replace it with hardware bought elsewhere.

(Yes, it could be annoying to have to spend your own money to fix a problem created by the Internet service you're already paying for. But unlike cable modems, at least DSL modems generally don't require paying a monthly rental fee that seems to escalate every year or so.)

The trick seems to be looking for one labeled as Verizon-compatible or designed for use with its DSL — starting with those listed on a Verizon DSL tech-support page. For example, an $80 Actiontec model so described has racked up a four-star average review at Amazon.

At another major DSL provider, AT&T, there's less mystery about bringing your own hardware. The company's site lists four different models you can buy directly. The company also says any other modem listed as supporting "ADSL, ADSL 2 and ADSL 2+" should work, and its tech-support site includes detailed instructions on setting up service with a third-party modem.

First, though, you should try a simpler option: moving the modem to a more central location higher up in your home. DSL should work through any phone jack in your residence, so you don't have to keep the modem where it was first installed.

Remember, however, that if the new outlet has one of the DSL filters that prevent DSL-induced interference on voice calls, you need to unplug it before plugging the modem into that jack.

Karl Bode, editor of DSLReports.com, suggested that you could also keep your existing modem but switch it to "bridge mode" (see this Verizon page's instructions) and then plug in a separate, more powerful Wi-Fi router.

Verizon's Mitchell noted yet another option: using a wireless range extender to expand the existing WiFi network. But that should be your last resort, because adding one will cut your bandwidth in half. And with DSL you don't have too much to spare in the first place: those connections often top out at 5 million bits per second, the minimum Netflix recommends for high-definition video.

You'd do better to connect a second wireless router via powerline networking to the first one, as outlined in this May Q&A column. That shouldn't cut into your download speed, although it will cost a little extra.

• Tip: "Retargeted" ads may betray your online gift shopping

If you've poked around the virtual shelves of any online stores, you've almost certainly been reminded of that at other sites by ads displaying the products you'd contemplated. That's the product of "retargeting," an increasingly common and often effective advertising tactic through which Web merchants try to close the deal by reminding shoppers of what they'd looked at earlier.

If you live by yourself, that's not necessarily a problem. But for everybody who shares both a home and a computer with recipients of their holiday generosity, retargeting can take all the suspense out of gift-giving.

You can prevent that by doing your shopping in a private-browsing or incognito window, as ZDNet's Violet Blue suggested a few days ago. Otherwise, your most effective remedy is the crude response Search Engine Land's Danny Sullivan recounted using last year: View enough listings for gifts you don't plan to give, and they'll push your intended gifts out of the retargeted ads.

Rob Pegoraro is a tech writer based out of Washington, D.C. To submit a tech question, e-mail Rob at rob@robpegoraro.com. Follow him on Twitter at twitter.com/robpegoraro.