====== E-652: Rohde & Schwarz ET-001 / ESM-2 ======
**E-652**, [[VHF]] / [[UHF]] receiving equipment **Rohde & Schwarz ET-001** with the receiver **ESM-2**; developed and produced by [[Rohde Schwarz|Rohde & Schwarz, Munich]].

The [[VHF]] / [[UHF]] receiving system ET-001 from [[Rohde & Schwarz]] was not only part of the [[P-728]] VHF direction finding system, but also used separately as a monitoring receiver with army designation **E-652**. 

{{:images:p-728-e-652-et001.jpg?direct&400 |P-728: Empfänger ESM2}}
===== Technical Data =====
  * [[Principle]]: [[Double conversion]]; [[IF]] 199,3 or 339,3 MHz; 10,7 MHz
  * [[Modes]]: [[A1]], [[A3|AM (A3)]], [[F3|FM (F3)]]
  * [[Frequency range]]: 25 - 1000 MHz
  * **Analog dial**, optional digital **frequency controller EZK**: digital display 1 kHz
  * [[Sensitivity]]: [[A3|AM (A3)]] 1 - 2 μV / [[Selectivity]] -3 dB: 15, 30, 250 kHz; 1 MHz

==== Power Supply ====
  * [[Mains]]: 220 V AC

==== Dimensions ====
  * 560 x 358 x 216 mm; 28 kg

==== Accessories ====
  * **Frequency controller EZK**: digital frequency display 1 kHz
  * **Panoramic display EZP**

----

===== Operation =====
The [[VHF]] / [[UHF]] receiver system Rohde & Schwarz ET001 carried the Swiss Army designation E-652 when used as monitoring receiver.

{{:images:e-652-rohde-schwarz-esm2-front.jpg?400 |P-728: Empfänger ESM2}} The VHF-UHF receiver **ESM2** covers 25 - 1000 MHz in nine band segments, it has an analog dial with a conventional tuning knob, reception modes [[AM]], [[FM]] and PULS are selectable. The IF bandwidths are 15, 30, 250 kHz and 1 MHz, the receiver has several AGC and MGC options.

The frequency can also be controlled with the frequency controller **EZK** with an up / down tuning switch featuring different tuning speeds; the digital frequency display with a resolution of 1 kHz is part of the frequency controller. The receiver can be controlled alternatively via TTL signals with BCD code or in master-slave mode from another receiver.

{{:images:e-652-rohde-schwarz-ezp-front.jpg?400 |P-728: Sichtgerät EZP}}  In the panoramic display **EZP**, a smaller or wider frequency range at the level of the second IF of 10.7 MHz can be displayed.


===== Technical Principle =====

==== Semiconductors ====
The set is completely solid state.

==== Development ====

==== Field use ====
The [[VHF]] / [[UHF]] receiving system ET-001 from [[Rohde & Schwarz]] was not only part of the [[P-728]] VHF direction finding system, but also used separately as a monitoring receiver with army designation **E-652**.

{{gallery>:images?p-728-e-652*.jpg&0&80x80&lightbox&showtitle&titlesort}}

==== Manuals ====

==== Additional information ====
  * [[http://armyradio.ch/radio-d/p-728.htm|P-728 auf www.armyradio.ch]]
  * [[http://www.radiomuseum.org/r/rohde_vhf_uhf_empfaenger_esm_2e.html|Receiver ESM 2 on www.radiomuseum.org]]