I created this list of reliable Usenet providers that offer free trials so you can test their service:
Eweka (No credit card required)
Eweka is a reliable Dutch Usenet provider that offers a truly hassle-free Usenet trial. No credit card is required for the 7 day free trial — you just need to provide a email address, and I discovered that they allow disposable email addresses.
Eweka is available to users in the United States, but you cannot use a IP address when registering for an account. In this case, you need a VPN to get a non-US IP address.
Eweka is a Highwinds Usenet feed provider.
Newshosting (Paypal or Credit Required)
Newshosting allows a 30 GB download limit on their trial accounts, and they give you access to the same service as a regular account. This includes access to their newsreader that has a built-in index search, and the ability to preview videos if there is a message with video attachments. They offers SSL connections and 2102 Days Retention.
Payment is via Paypal or credit card. Exact terms are “Free Trial is over in 14 days or 30GB used, whichever comes first. Free trial is offered for new customers only, one per customer.”
UsenetServer (Credit card required)
Usenetserver offers another pretty good deal — a three day trial for $3. Note that this only for non-SSL Usenet connections. If you want SSL connections you need to pay an extra $2.
I signed up to test the basic trial, and found the downloads speed reasonable (around 2Mbps — I usually max out at 4-6Mbps using other services). You get 10 connections with the trial.
Link: 3 Day Trial Usenetserver