The Reinartz Tuner

[ms660]

The original 1922 WW article can be found here:

http://www.americanradiohistory.com/...ld-1922-05.pdf

Many circuits claim to be the Reinartz circuit when they're not, at least that's wot I think.

Lawrence.

[Skywave]

Just for reference and to help others. That link loads a pdf that is over 100 pages long. The article in question appears on pdf page #35.

Al.

[Skywave]

Originally Posted by pwdrive

Many circuits claim to be the Reinartz circuit when they're not, at least that's wot I think.

I looked up the Reinartz cct. in the Practical Wireless Encyclopaedia, 12th. ed., 1951; page 251 refers. The cct. shown there is essentially the same as in that article in the given 'Net link.

The same P.W. Encyclopaedia also shows the Hartley cct. on p.148. The essential difference between the two seems to be that the reaction control in the Hartley is by a variable capacitor between anode and R.F. ground (with a fixed capacitor between anode and coil), whereas the in the Reinartz the variable capacitor is between anode and the coil itself: both circuits use only one coil for tuning and reaction. Hence there appears to be little essential difference between them - which might go some way to explain Lawrence's remark above.

Regarding the valve as an oscillator then, it seems that in the Hartley the variable reaction capacitor is in parallel with the valve output, whereas in the Reinartz it is series with it. Consequently, in the Hartley, increasing that variable capacitor reduces the amount of feedback, but in the Reinartz, it has the opposite effect: it increases it.

Now I do not have much experience of evaluating the difference in performance of these two circuits, but I would expect that difference to be marginal, with the most significant differences brought about by the physical and electrical nature of the single coil, knowing how critical the coil can be in such ccts. for short-wave work, with all other components and parameters remaining unchanged.

So much for my brief analysis & conclusions. What do others think?

Al.

[ms660]

The Reinartz has a few short comings by later standards but at the time it apparently caused quite a stir, something to do with some of the Trans-Atlantic tests at that time so far as I can gather so I suppose it could be called a milestone, hence the circuit in the post.

Looking at the circuit the key features seem to be the multi tapped inductors and the use of a variable capacitor to control the amount of feedback, I think the original used flat wound coils, many of the ones constructed during that period used coils wound in solenoid form to make construction easier.

Lawrence.