Direction Finding Receivers - Peilgeräte

[Yuri D.]

This is not a very sharp picture, but the controls and principle are similar to the EP2 machine. You have a switch with two positions: Peilen and Seiten. Peilen is the yellow dot. Seiten is the blue/red dot. You do have to turn the receiver on its base to find the minima for each side-cardioid. Yes looks like you don't have to rotate the EP2 antenna to find the direction because of the cross-loop.

[Funksammler]

Thanks, now I understand!

regards,

Funksammler

[Yuri D.]

Funksammler, do you have a manual for the EP2a that has a page with its antenna radiation patterns?

[Funksammler]

I do have a copy of the manual, but it does not contain the antenna radiation patterns. But since they are simple loops (albeit square loops), they will have the standard figure of 8 and heart shapes.

The main loop has a figure of 8 pattern ("B" below) and is used to find the minimum. The secondary loop is placed at a 90 degree angle, so if the main loop is at it's minimum, the secondary loop will be at it's maximum. If the signal from the sense antenna is now added to the signal from the secondary loop, the secondary antenna will have the heart shaped diagram, with the maximum point forward ("C" below, but turned 90 degrees); if the secondary loop antenna signal is substracted, the heart shape will be oriented with it's maxiumum backwards ("D" below, again 90 degrees turned) . So by simply switching the polarity of the secondary loop you get a strong signal at one position and a weak signal at the other which indicated if the transmitter is ahead or behind.

The sense antenna also has a second function: Due to reflections in nearby conductors false signals will occur so that the received signal is not always zero at the minimum. By mixing in a small proportion of the signal of the sense antenna via a capacitor, these false signals can be countered so that the minimum becomes sharper. The Germans call this "enttruebung"

regards,

Funksammler

[Yuri D.]

Better P57N photos. Note the "Peilung/Seite" switch and the red and blue arrows on top of the unit. Also note the red and blue dots on the rotation indicator. Once this is switched to the right (half blue/half red circle) the antenna can be turned to find the minima. I always liked the concept of physically turning the antenna.

[Yuri D.]

another photo

[Yuri D.]

And the two Luftwaffe units:

[lz1pv]

Spez975F

http://www.cdvandt.org/Tel-data-Spez2036.pdf
https://picasaweb.google.com/1097768...52745028278434
https://picasaweb.google.com/1097768...52900994484354



Nick

[Funksammler]

http://www.cdvandt.org/Tel-data-Spez2036.pdf
https://picasaweb.google.com/1097768...52745028278434
https://picasaweb.google.com/1097768...52900994484354



Nick

Thanks for sharing the information on the Impulspeilanlage. For a short while before the war, the FuG 10 installation in Luftwaffe aircraft were equipped with automatic Impuls generators for navigation purposes, I guess the Impulspeilanlage was particularly suited to work with this system. The disadvantage was that the enemy could as easily find the aircraft so the system was discontinued at the outbreak of war and replaced by transponder systems such as the X and Y-Geraete working on VHF.

regards,

Funksammler