====== P-729 ======
**Visual direction finder P-729**, **Plath SFP 218.44**; manufactured by [[Plath|C. Plath GmbH, Hamburg]].

For the planned replacement of the VHF direction finder [[P-725_1|Telegon IV]] from Telefunken, troop trials were carried out in 1983/5 with two [[Plath]] SFP 218.44 direction finders installed in Pinzgauer trucks. The system itself was not introduced in this configuration, but led to the replacement of the Telefunken Sig 638 as part of the upgrade of the [[P-725 (2)]].

===== Technical data =====
{{ :images:p-729-plath-sfp-218-44-cplt.jpg?direct&400|}}
  * [[Principle]]: Visual direction finder [[Plath]] **SFP 218.44**
  * [[Receiver]] [[Plath]] **SFP 218.44**: [[Double conversion|Triple conversion superhet]], [[IF]] 400 MHz, 9 MHz, 470 kHz
  * [[Operation modes]]: [[A1]] with BFO, [[A2]], [[A3|AM (A3)]], [[F3|F3 (FM)]]
  * [[Frequency range]]: 20 - 180 MHz; digital display, 100 Hz
  * [[Sensitivity]]: [[A3|AM (A3)]] 0.6 - 1.5 μV / [[Selectivity]] - 3 dB: Hearing channel 5 / 80 kHz; DF channel 5 kHz

==== Power supply ====
  * Mains operation]]: 220 V alternating current mains

==== Dimensions ====

==== Accessories ====
  * **Direction finding antenna**: H-Adcock A 1262 V DF antenna with AA 1164 remote controller

===== Operation =====
The core component is the [[Plath]] SFP 218.44, the DF receiver and visual bearing indicator, in which a round cathode ray tube DP 10/14, is used. A round bearing dial is manually aligned with the maximum deflection on the visual display and the bearing is output digitally.

{{:images:p-729-plath-sfp-218-44.jpg?direct&400|P-729}}\\ For frequency input, the FD 5002 frequency decade, the FVV 219 / FDK 216 frequency multiplier and the AG 5002.4 tuning adaptor are required to set the direction finding system to the correct frequency.

Only these components allow the frequency to be entered directly via a keypad or set in 100 Hz steps using the tuning knob. The display unit alone does not have a frequency input or tuning facility.

The 8-fold H-Adcock antenna A-1262-V from AEG-Telefunken with eight dipoles is used as the direction finding antenna; the 10.5 m antenna mast was carried on a single-axle trailer.

===== Technical principle =====


==== Tube assembly ====


==== Development ====

==== Deployment ====
Two units of the [[Plath]] SFP 218.44 direction finding system dating from 1974 were procured around 1980. The system installed in a Pinzgauer 6x6 off-road vehicle did undergo troop trials in 1983/85, after which the Plath visual direction finder was used in the upgraded [[P-725_2|P-725/m (2)]] direction finder.

Both systems were liquidated in 2002.
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===== Technical documentation =====
  * {{ :manuals:p-725-plath-sfp218-4.pdf |Sichtfunkpeiler SFP 218.4, Plath GmbH, Hamburg}}
==== Further information ====
  * [[http://armyradio.ch/radio-d/p-729.htm|P-729 at www.armyradio.ch]]
  * [[http://www.radiomuseum.org/r/plath_sichtfunkpeiler_sfp_218_43.html|Plath SFP 218.43 on the website of www.radiomuseum.org]]