Where can I get an anonymous Rav Kav card issued?

You can get an anonymous Rav-Kav on every bus.

Israeli here, you can buy an anonymous Rav Kav on any bus when you board it. It costs 5 NIS. In fact it's the only pay with cash when boarding the bus.

This is what it looks like (sorry for the poor photo quality from my computer). The "Dan" in the center is the bus company whose driver I bought it from and you will notice the lack of photo.

Quoting the Israeli Ministry of Transportation:

Anonymous Rav-Kav

Available for purchase for NIS 5 at sales points including: bus drivers, central bus station, large train stations, info and service centers and at the light railway service center in Jerusalem.

• Does not save travel information
• Does not insure the rest of stored value in case of loss and or theft.
• No reconstruction of tickets In case of expiration

Disributing Rav-Kavs is done by the transportation companies, quoting the largest one in central Israel hebrew source:

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Which is

An anonymous Rav-Kav is a ticket purchase-able from bus drivers for 5 NIS. The anonymous card holder is not ensured in the case the card is lost and card information cannot be retrieved.

And Egged (the other big one from Jerusalem) English Citation:

In contrast to the Personal Rav Kav Card, passenger's personal details are not required when applying for Anonymous Rav Kav Card. An Anonymous Card issued for a one-time payment of NIS 5.00 and may be purchased from the driver or at sales points.

Purchase the card from the bus driver or at one of the Al Ha-Kav issue stations for a one-time cost of NIS5.00

There is now a Rav Kav sales point at Ben Gurion airport, at terminal 3, in the arrivals hall, next to exit 2.

The Rav Kav website maintains a list of sales points with address and opening hours. I don't know how accurate or complete this information is.

You can also buy an anonymous Rav-Kav from a bus driver, with some initial stored value. (Note that since 2019, drivers will not recharge a Rav-Kav that you already have.) But beware that it's not guaranteed in practice that the driver will have spare Rav-Kav available.

As far as I know, you cannot buy a Rav Kav from a ticket machine at a train station (but you can recharge one), even an anonymous one. You need to visit a station with a service point during opening hours. The same applies to the Jerusalem light rail.

In Haifa, you can buy an anonymous Rav Kav from ticket vending machines located at many bus stops.

You can buy a Rav-Kav at many central bus stations around the country, and the Tel-Aviv train stations. However, the opening hours for the train station Rav-Kav booths are annoyingly limited! (not sure about the bus station booths.)

If you want to have everything prepared in advance, you can also head to Ebay and purchase a Rav Kav card in advance by having it shipped to your home address. Some sellers even offer pre-charged Rav Kav cards, so you won't even need to top them up on arrival.

This is obviously a more expensive option, as all resellers charge a fee for their services.