View source for AN/PRC-77 Portable Transceiver

{{Short description|Military tactical radio transceiver}}
[[Image:PRC-latrun-exhibition-1.jpg|thumb|AN/PRC 77 radio and handset]]
[[File:KY38Manpack.jpg|thumb|[[United States in the Vietnam War|American soldier]] using the KY-38 "man-pack", part of the [[NESTOR (encryption)|NESTOR voice encryption system]] that was used during the [[Vietnam War]]. The upper unit is an AN/PRC-77 radio transceiver. The combined weight of the units, 54 pounds (24.5 kg), proved an obstacle to their use in combat.]] 
[[File:BEST OF THE MARINE CORPS - May 2006 - Defense Visual Information Center (5354367147).jpg|thumb|[[United States Marine Corps|U.S. Marine]] carrying a PRC-77 during a training exercise in 1989]]

The '''AN/PRC-77 Portable Transceiver''', also known as '''AN/PRC 77 Radio Set''', is a man-pack, portable [[VHF]] [[frequency modulation|FM]] [[combat-net radio]] [[transceiver]] manufactured by Associated Industries<ref name="manuf">[http://www.associated-ind.com/], Manufacturer's website.</ref> and used to provide short-range, two-way [[radiotelephone]] voice communication.<ref>{{cite book| author=Mark Francis, KI0PF |title=Mil Spec radio gear - Korean War to present day |year=2005 |publisher= CW Communications, Inc |isbn=0-943016-33-9 |location=Hicksville, NY| pages=171–176}}</ref> 

In accordance with the [[Joint Electronics Type Designation System]] (JETDS), the "''AN/PRC-77''" designation represents the 77th design of an Army-Navy electronic device for portable two-way communications radio. The JETDS system also now is used to name all [[Department of Defense]] electronic systems.

== History ==
The AN/PRC-77 entered service in 1968 during the [[Vietnam War]] as an upgrade to the earlier '''AN/PRC-25'''. It differs from its predecessor mainly in that the PRC-77's final power amplifier stage is made with a transistor, eliminating the only vacuum tube in the PRC-25, as well as the DC-DC voltage converter used to create the high plate voltage for the tube from the 15 V battery. In addition, the PRC-25 could not support [[Secure voice|voice encryption]] devices, but PRC-77 transmitter audio bandwidth was widened to give it the ability to use the TSEC/KY-38 [[NESTOR (encryption)|NESTOR]] voice encryption system used in Vietnam, and the later KY-57 [[VINSON]] family. Problems were encountered in Vietnam with the combination as described in the NESTOR article. The transmitter's spurious emissions were cleaned up to create less interference to nearby receivers. The receiver's performance was also hardened in the PRC-77 to enable it to better reject interference suffered from nearby transmitters, a common operating set up that reduced the effectiveness of the PRC-25.<ref>Military Communications A Test for Technology CMH_Pub_91-12-B, pg 201 and Army procurement decision B-161031, JUN. 1, 1967</ref>  The receiver audio bandwidth was also increased to operate with the encryption equipment.<ref>B-161031, JUN. 1, 1967</ref>

There were no changes to the external controls or looks, so the two radios looked and the operating controls were the same. The equipment tag glued to the edge of the front panel was the main (external) way to tell the difference.  The original batteries had a 3 V tap (series diode-reduced to 2.4 V) for the PRC-25's tube filament. This remained unchanged so the batteries could operate either radio it was placed in, but the PRC-77 did not use the 3 V tap at all.  With the more efficient all-transistorized circuitry, and without the DC-DC step-up voltage converter for the tube, the common battery lasted longer in the PRC-77 under the same conditions.  "OF THE TWENTY-FIVE (25) ELECTRONIC MODULES ORIGINALLY USED IN BOTH THE TRANSMITTER AND RECEIVER PORTIONS OF THE AN/PRC-25, ONLY EIGHT (8) OF THE MODULES USED IN THE AN/PRC-77 ARE INTERCHANGEABLE WITH THE AN/PRC-25.'"<ref>B-161031, JUN. 1, 1967 https://www.gao.gov/products/b-161031</ref>

Today the AN/PRC-77 has largely been replaced by [[SINCGARS]] radios, but it is still capable of inter-operating with most VHF FM radios used by U.S. and allied ground forces.<ref name="olive-drab.com">http://www.olive-drab.com/od_electronics_anprc25.php AN/PRC-25 and AN/PRC-77, Olive-drab.com</ref> It was commonly nicknamed the "prick-77" by U.S. military forces.<ref name="Dickson2011">{{cite book|first=Paul|last=Dickson|title=War Slang: American Fighting Words & Phrases Since the Civil War|url=https://books.google.com/books?id=ixTBwQWX7F8C&pg=PA425|year=2011|publisher=Dover Publications|isbn=978-0-486-47750-3|pages=425–}}</ref>

== Technical details ==
The AN/PRC 77 consists of the [[RT-841]] transceiver and minor components. It can provide [[secure voice]] (X-mode) transmission with the TSEC/KY-57 [[VINSON]] voice [[encryption]] device, but is not compatible with the SINCGARS [[Frequency-hopping spread spectrum|frequency hopping mode]].<ref name="olive-drab.com"/> During the [[Vietnam War]], the PRC-77 used the earlier TSEC/KY-38 [[NESTOR (encryption)|NESTOR]] voice encryption system.

'''Major components:'''

*Transmitter/Receiver unit
*Battery

'''Minor components - CES (Complete Equipment Schedule):'''

*3&nbsp;ft antenna - 'bush/battle whip'
*10&nbsp;ft antenna
*3&nbsp;ft antenna base - 'gooseneck'
*10&nbsp;ft antenna base
*Handset
*Harness

{| cellpadding="2" cellspacing="0" border="1"
|- 
! colspan="2" style="background-color: #c0c0c0" |Technical characteristics<ref name="spec">[http://www.associated-ind.com/pdf/ANPRC77.pdf], Manufacturer Datasheet.</ref>
|-
! style="background-color: #dfdfdf;" | Channels: 
| 920 channels across two bands using 50&nbsp;kHz steps
|-
! style="background-color: #dfdfdf;" | Frequency Ranges:
| 30.00 to 52.95&nbsp;MHz (Low Channel);<br />53.00 to 75.95&nbsp;MHz (High Channel)
|-
! style="background-color: #dfdfdf;" | Estimated Range:
| 8&nbsp;km (5&nbsp;mi) Dependent on conditions
|-
! style="background-color: #dfdfdf;" | Power Output:
| 1.5 to 2.0 watts
|-
! style="background-color: #dfdfdf;" | Power Source: 
| Current (2015) military batteries:<br />BA-5598/U LiSO<sub>2</sub> nonrechargeable<br />BB-386/U NiMH and BB-2598/U Li-ion rechargeable<br /><br />Obsolete (unavailable) nonrechargeable military batteries:<br />BA-386/PRC-25 zinc-carbon, BA-398/PRC-25 zinc-carbon cold weather vest (use w/cable to radio battery connector), [[BA-4386]]/PRC-25 magnesium<br /><br />Discontinued but available military or equivalent batteries:<br />BA-3386/U alkaline nonrechargeable<br />BB-586/U NiCad and BB-LA6 SLA rechargeable
|-
! style="background-color: #dfdfdf;" | Antenna:
| AT-271A/PRC {{convert|10|ft|m|abbr=on}} multi-section whip "Static" [[Whip-a-way]], or<br />AT-892/PRL-24 3&nbsp;ft semi-rigid steel tape "Bush-whip",
|-
! style="background-color: #dfdfdf;" | Type of Service:
| 30K0F3E emission (FM)<br />Manpack field radio<br />[[land mobile service]]

|-
! style="background-color: #dfdfdf;" | Weight:
| 13.75&nbsp;lb (6.2&nbsp;kg)
|-
! style="background-color: #dfdfdf;" | Security
| Could be used with TSEC/KY-38 [[NESTOR (encryption)|NESTOR]] and, later, the KY-57 [[VINSON]] [[secure voice]] systems. 
|-
! style="background-color: #dfdfdf;" | Note:
| A modified version of the AN/PRC-77 is available and is designated<br />AN/PRC-1177.  This version has been enhanced to allow a smaller <br />channel step of 25&nbsp;kHz and to reduce voice bandwidth to 6&nbsp;kHz. These<br />features combine to double the number of available channels to 1840. 
|-
|}

== Users ==
[[Image:PRC-77.svg|thumb|right|250px|Control Panel of a PRC-77]]
{{more citations needed section|date=August 2023}}

*{{flag|Austria}}: The [[Austrian Federal Army|Austrian Army]] still uses the AN/PRC-77, though in a limited capacity such as training cadets in radio communications. For border patrol the Austrian Army now uses a new device called "TFF-41" (Pentacom RT-405), which is capable of frequency-hopping and digital encryption. The Austrian Army also uses the AN/PRC-1177 for example the Austrian AN/PRC-77 have a special switch for a 25&nbsp;kHz mode, which reduces the bandwidth of the selected channel by 25&nbsp;kHz and therefore doubles the number of available channels.
*{{flag|Bangladesh}}: The [[Bangladesh Army]] use the AN/PRC-77 as a section level communication equipment. In Chittagong Hill Tracts area it is still used for operations. Some modified/improvised local antenna concepts often increase the communication range up to 15–20&nbsp;km. Now being phased out by far superior Q-MAC's VHF-90M
*{{flag|Brazil}}: In Brazil it is used by [[Brazilian Army]] It was nicknamed EB-11 RY-20/ERC-110 manufactured by Associated Industries U.S.A and manufactured by [[AEG Telefunken]] do Brasil S/A, São Paulo 1970 the radio is used today but is now being replaced but still the PRC-77 remains stored in military units also used for training of technicians in military communications sergeants communications.
*{{flag|Chile}}: The Telecomm Regiments in the [[Chilean Army]] still using the PRC - 77. (In process of modernization).
*{{flag|El Salvador}}: Salvadoran military and security forces used both American and Israeli-manufactured versions during the civil war.<ref>{{cite web |url=https://www.soc.mil/ARSOF_History/articles/v3n1_paraiso_page_1.html |title=El Paraiso and the War in El Salvador: Part I (1981–1983) |website=www.soc.mil |url-status=dead |archive-url=https://web.archive.org/web/20190411234721/https://www.soc.mil/ARSOF_History/articles/v3n1_paraiso_page_1.html |archive-date=2019-04-11}}</ref>
*{{flag|Finland}}: The [[Finnish army]] uses this radio as a "battalion radio", using it as a common training device.  The radio is designated LV 217 'Ventti-seiska' ('ventti' is Finnish slang for '21', from the Finnish variant of [[blackjack]]), slowly being phased out of reservist service. FDF also operates '''PRC-1077'''<ref>{{cite web |url=https://www.radionerds.com/index.php/PRC-1077|title=PRC-1077|website=www.radionerds.com}}</ref> under the designation {{Interlanguage link|LV 217M|fi|LV_217M}}.
*{{flag|Israel}}: The [[Israel Defense Forces]] used this radio extensively from the early 1970s to the late 1990s, when it was gradually replaced by modern digital devices. However, it can still be found in some units, mostly in stationary temporary posts.
*{{flag|New Zealand}}: The [[New Zealand Defence Force]] used the '77 set' as its VHF combat arms communications equipment, both manpack and vehicle-mounted [[Land Rover series|Land Rover]] 'fitted for radio' (FFR) variants, from the late 1960s until the 1990s. It came into New Zealand service with a lot of other US equipment during New Zealand's contribution to the [[New Zealand in the Vietnam War|Vietnam War]], replacing the New Zealand-built ZC-1 and British equipment dating back to the Second World War. 
*{{flag|Norway}}: The AN/PRC-77 has been replaced as a main source of radio communication for regular forces of the [[Norwegian Army]] by indigenously developed radio sets called [[Multi Rolle Radio|MRR]] (Multi Role Radio) and LFR (Lett Flerbruks Radio) (Norwegian for Light Multi Role Radio), and other modern radios. However the Norwegian Army did not throw these radio sets away. Instead many of them were handed over to the Home Guard which still uses it as their backup radio as there is a limited supply of MRR sets for the force totalling 40 000 soldiers.
*{{flag|Pakistan}}: The [[Pakistani Army]] has used the set for the past 25+ years. Purchased from different sources including the US, Brazil and Spain, it is scheduled to be replaced in the next 5 years.
*{{flag|Peru}}: Used alongside the French [[TRC 372]].<ref name="sof90">{{cite magazine |last=Marks |first=Tom |date= January 1990 |title=Professionals In Paradise |magazine=Soldier of Fortune|publisher=Soldier of Fortune}}</ref>
*{{flag|Philippines}}: The [[Philippine Army]] made extensive use of the AN/PRC-77 for several decades until they were phased out of service with the introduction of newer manpack radios such as the Harris Falcon II during the 2000s.
*{{flag|Singapore}}: The Singapore Armed Forces formerly used the AN/PRC-77 up to around the 1990s.
*{{flag|Spain}}: The Spanish Army, Spanish Navy (Armada Española), Spanish Marines and Spanish Air Force formerly used the AN/PRC-77. It was replaced by the French PR4G since 2002
*{{flag|Sweden}}: In the [[Swedish Army]] the radio system goes under the name Radio 145 and Radio 146 (Ra145/146), predominately the Homeguard (National Guard) is issued the Ra145/146.
*{{flag|Swiss}}: The [[Swiss Army]] used the radio as SE-227.
*{{flag|Taiwan}}: The [[Republic of China Army|Taiwanese army]] nicknamed the radio as "77", and had used it for over 40 years when AN/PRC-77, along with AN/VRC-12,<ref>{{Cite web|url=http://city.udn.com/forum/article.jsp?no=59263&cate_no=0&pno=3&aid=2893526|title=立委：國產3武器明年量產|date=2010-09-17|website=國際軍武網友聯誼會|access-date=2018-11-17}}</ref> were replaced by indigenous radio systems in 2010s.<ref>{{Cite news|url=https://www.mobile01.com/topicdetail.php?f=37&t=1762028|title=超耐用通訊77終於要退休了 ...|date=2010-09-18|website=Mobile01|access-date=2018-11-17}}</ref>
*{{flag|Thailand}}: Still found in some units within the [[Royal Thai Army]]

==Photo gallery==
<gallery>
Image:EB-11 RY-20.ERC-110 of the Telefunken do Brasil S.A,DSCF69200.JPG
Image:EB-11 RY-20.ERC-110 of the Telefunken do Brasil S.A,DSCF6920.JPG
Image:EB-11 RY-20.ERC-110 of the Telefunken do Brasil S.A,DSCF6922.JPG
Image:EB-11 RY-20.ERC-110 of the Telefunken do Brasil S.A,DSCF6924.JPG
Image:EB-11 RY-20.ERC-110 of the Telefunken do Brasil S.A,DSCF6923 - Cópia.JPG
Image:Conjunto ERC 202 30Watts.DSCF6919.JPG
</gallery>

==See also==
{{Portal|Electronics}}
* [[List of military electronics of the United States]]

==References==
{{reflist}}

==External links==
{{commons category}}
*[http://www.olive-drab.com/od_electronics_anprc25.php AN/PRC-25 and AN/PRC-77 at Olive-drab.com]
*[http://www.prc68.com/I/PRC77.shtml PRC-77 Back Pack Squad Radio]

{{DEFAULTSORT:AN/PRC-77 Portable Transceiver}}
[[Category:Military radio systems of the United States]]
[[Category:Military electronics of the United States]]
[[Category:Military equipment of the Vietnam War]]
[[Category:Military equipment introduced in the 1960s]]