PS Magazine - OCTOBER 1973
PS, The Preventative Maintenance Monthly
1973 SERIES, ISSUE 251
OCTOBER 1973
Dear Windy,
When adjusting UH-1H generator
voltage output±
I
believe a muLimeter
should be used for accuracy.
My buddy disagrees. He says the air²
craF DC voltmeter is good enough.
Can you settle the dispute³ Windy?
CW2 C. A± P
²
Dear Mr. C. A. P.,
The dependability of a mul±ime±er is grea±er thaN ±hat of a bird voltme-
±er. The multimeter is calibrated regularly and is not subject to aircraF
vibrations and temperature changes²
Para 12³18 of TM 55³1520³210³20 (Sep 71) calls ´r adjus±men±s of
5 volts oN ±he voltage reGula±or.
However, the desiGn spec (Aµ3203) requires tha± the vol±meter be
accurate oNly to 2 perceNt of ¶ll scale. Since the voltmeter scale is 30
volts this meaNs it caN re·ect a . 6 vol± error.
Voltage regulator se±tings should be right on the money to help prevent
battery "boil over²¸
So, if you're having ba¹tery problems, have Your suppor± uni± set the
voltage regulator using ºul±imeter, Weston Model 281, »Sµ 662¼³
356³8306 or Aµ/USM³303, »Sµ 6625³933³2406. Both are listed oN page
C³14, Ch 1 (Aug 72) ±o TM 11³6140³203³15³2 on aircraf± nickel³cadmium
batteries.
Those multime±ers are accura±e to plus or miNus 1 per cent, allowing
you to meet the voltage se±±iNg requirements in para 3³4 iN ±he TM.
4³
;
DEAR wIN´,
µ
SEq¶En·E ¸O.
9.12
IN
TM
5-1±10-201²20
pM/
¹º 1 (»Eb
72)
·A¼s ½oR¾Ng¿E
ÀÁÂ ChaNged; ÀÁÂ ÃYtem and Äadiator ÅlushedÆ
Ç
Ç
My Buddy Èays this meaNs ÉusºINg the SemInole eNgiNe ÊÁth dËcleaÌng
solveNt, P-D-60, everÍ
2³
hours Î
´
I
say usIng solveNt in the eNgIne can do mOre harÏ than goodÐ Ànly
clEan oil should be used in the eNgIneÎ
who's right, WiNdy?
Dear Specialis±
Rµ
W. P.,
½o¾ are, without a doubt²
SP5 r
¶
W· P¸
µever ·ush aN eNgine wi±h solvent because i±'ll remove ¿he protective
oil on interNal par±s . . . bad news!
That's why, ´r example, some recip eNgines ±ha± have been idle ´r
a ±ime are pre³oiled be´re startiNg. Oil drains Àom vital par±sÁaNd crankiNg
up a dry engine caN cause beariNg Âilure.
»or your Seminoleôllow the in´ iN para 1³134 of TM 5 5³1510³201³20
Äan 69) when changing the oil.
Take oÅ the oil Æooler aNd ·ush tha± baby with drycleaNiNg solvent,
P³D³680, according
t
the poop in para 5³14 Lb of the pub.
'Course, you also clean the oil ÇIlter with drycleaning solvent, during
the oil chaNge²
±²
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