…continuation of previous post. The frequency counter was made using an $18 module from eBay. It is accurate to 0.5KHz, however it will flatten an 9v battery < 4 Hours (Carbon-Zinc Type).
Sennheiser HD-25 Mark II (Headphones Pictured) Review Below
The Headphones are ‘special edition’ Sennheiser HD-25 Mark IIs. The HD-25 is an industry standard monitoring headphone, known for its very accurate bass response, clear to the point of harsh treble, and general inability to ‘hide’ any imperfections in audio. If you look closely, you will see them in use in most commercial television coverage of sporting events etc, especially motor car racing and afl football. That particular set was a special Adidas co branded promotion, which makes absolutely no difference to the product technically, however they included a better quality lead, and an extra set of velour earpads (not shown, in use on an older set that needed new ones). They also featured (garish?) blue styling and the Adidas logo, but I got them at a very special discount, so who is to complain?
If you are in need of a good station headphone, I cannot more highly recommend the HD-25. Many many times they have allowed me to work DX on a basic radio, such as my Alinco DX-SR8T, or my vintage FT-101E. They provide excellent isolation from the noise of the QTH, especially ‘AF QRM’, which I had a lot of due to a faulty XYL which exploded and became an XXYL. Anyway I digress in many ways. The Sennheiser HD-25 Mark II has an impedance of 70 Ohms, however other impedance versions are available, such as a 300 Ohm model, and the 16 Ohm ‘Amperior’ spin off. The driver is 30mm, and the headphones can handle A FULL WATT. My first pair was bought in 2005, and are still going strong as my primary station headset.