More info from Bob WO6W and Marc, DL2KMA

Since David has posted... Here's a second Twin-T Code Prectice Oscillator (CPO) from the same vendor. This model has both volume and pitch controls for just a few dollars more:

This second unit (URL above) is one of several alternatives we share in the Sending Prep class. Two other alternatives, CW Hotline and Morserino, don't sound as good, but have additional functionality that can be useful after a new user has an HF rig providing a really nice CPO functionality.

The CW Hotline is especially nice as it is relatively inexpensive when purchased as an easy to build kit ($55 or so...). CW Hotline supports:

  Straight key as well as keyer functionality,

  > Vband connection over a USB port,

  > A wifi capability allowing CW Hotline functionality - operate CW with other Hotline users over the web,

  > A pair of Hotline boxes can be used to remote-key a radio using a manual key. (I use a pair of Hotlne devices along with Smart SDR on an iPad to remote operate a Flex transceiver)

Note that we cover all of the options above in the Sending Prep class. We also go into some depth on using an HF radio for code practice.

The next Sending Prep class is conveniently held tomorrow - Monday.

SENDING PREP! MONDAY at 6:00PM EST (2300 UTC)!

Mondays at 6PM Eastern (2300 UTC) in Zoom A.

Zoom A: 454 032 7566, PASSCODE: 941962, Zoom A Link

73

Bob WO6W

Also 

Maybe this is an alternative:

from UK, buyable ait ebay or under https://www.kanga-products.co.uk/

73

Marc, DL2KMA