Login: GUEST @ JH4XSY.14.JNET1.JPN.AS [Tsuchiura]
home | newest check | boards | help index | log | ps | userlogin | send sysop | slog | status forward | bcm news | users | version | remove cookie
G8MNY > TECH 23.12.25 17:08l 160 Lines 7859 Bytes #6 (0) @ WW
BID : 47748_GB7CIP
Subj: Palstar AT1500CV ATU
Path: JH4XSY<JE7YGF<LU4ECL<LU9DCE<VE3TOK<VE3KPG<GB7CIP
Sent: 251223/0743Z @:GB7CIP.#32.GBR.EURO #:47748 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To : TECH@WW
By G8MNY (Updated Jan 19)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ FEATURES
ｳ ｳ/~~~\ｳ � � ﾞ ｳ 4:1 Balun transformer for balanced output.
ｳ ｳ__ __ｳ /~~\ /~~\ ....... ｳ Direct: coax 1, & 2, & bypass outputs.
ｳ ﾀﾄﾄﾄﾄﾄﾙ | () | | () | : : ｳ Tuned: coax 1, & 2, & wire outputs.
ｳ ::ﾜ:: \__/ \__/ : �: ｳ 300W & 3kW cross needle lit power meter
ｳ '' '' :.....: ｳ 60W & 600W reflected.
ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ The T arrangement C L C has verniers & a
counter on the inductor.
This unit is not fitted with the same sized capacitors, or smaller rotary
ceramic & wire roller coaster as shown in the 2 Radcom articles below (*), but
it uses slightly smaller capacitors (still 4.5kV rated) & a large surface area
static silver plated flat spiral coil (very high Q) with a rotating internal
2 surface griping roller, simular but bigger than the one used in the MFJ 989D.
_ _ INTERNAL LAYOUT SIMPLIFIED CIRCUIT
ﾚﾁﾄﾁﾂﾄﾁﾄﾁﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ Direct Outputs
ｳ S ｳ (\\\\\) v Fire ｳ Wire xﾄﾄｿ
ｳ W ｳ T ﾜﾜﾜﾜﾜﾜﾜﾜﾜｳ Tx(�)ﾄ[SWR]ﾄ>oﾄﾄﾄ(�)Coax1ﾄﾄﾄﾄｿ ｳ o<ｿWAFER
ｳ R ｳ ﾞｳ oﾄﾄﾄ(�)Coax2ﾄﾄｿ ｳ ｳ o ｳSWITCH
ｳ~~SW ======= ======= ﾞｳ oﾄﾄﾄ(�)Thu ｳ ｳ ｳ o ｳ
ｳ ﾜﾜﾜ ======= ======= ﾞｳ Via oｿ ｳ ｳ ﾀﾄo ｳ
ｳ ｺ ==C1=== ==C2=== ﾞｳ oｴ ｳ ﾀﾄﾄﾄo ｳ
ｳ ｺ ======= ======= ﾞｳ ATU oｴ RF HOT ﾀﾄﾄﾄﾄﾄo ｳ
ｳ ｺ ======= ======= ﾞｳ ﾀﾄﾄﾄｴﾃﾄﾄﾄﾂﾄﾄﾄｴﾃﾄﾄﾄﾄﾄﾄﾙ
ｳ ｺ ======= ======= ﾞｳ WAFER C1 ) C2 ﾚﾄﾄx
ｳ ｺ ======= ======= ﾞｳ SWITCH L)<ｿ _(|
ｳ ｺ ======= ======= ﾟﾟﾟﾟﾟﾟﾟﾟﾟｳ ) ｳ ｳ (|T
ｳ ｺ ｺﾚﾄﾄﾄﾄﾄｿｺ [ｺ] ｳ ) ｳ ｳ ﾀﾄﾄx
ﾀﾄﾄﾗﾄﾄﾄﾄﾄﾄﾗﾁﾄﾄﾄﾄﾄﾁﾗﾄﾄﾄﾄﾄﾄﾄﾄﾗﾄﾄﾄﾄﾙ ﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾁﾄﾁﾄﾄﾄﾄﾁﾄﾂﾄﾄx
ﾟﾟﾟ ﾟﾟﾟﾟﾟ ﾟﾟﾟﾟﾟ ﾟﾟﾟﾝ T ATU ﾁ
SWR CIRCUIT
Rig
(�)ﾄﾄﾂﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾂﾄ>Switch Ref 60W +1K2
=== Cal ((((() Cal === ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄo<ﾄﾄﾄﾄﾄﾂﾄﾄﾄﾄ(M)ﾄｿ
6p8ｳ / ｳ16T ｳ \ ｳ6p8 ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄo600W ===10n ｳ
ﾃﾄｴﾃﾄﾂﾄｴ<ﾃｴ ﾃｴ>ﾃﾄﾂﾄｴﾃﾄﾄｴ ｳ ｳ 300W ﾁ ｳ
10pｳ ) ｳ ｳ ) ｳ10p ｳ ｳ ﾚﾄﾄﾄﾄﾄo<ﾄﾄﾄﾄﾄﾂﾄﾄﾄﾄ(M)ﾄｴ
=== )680 22R 22R )680 === ｳ ｳ ｳ ﾚﾄo3KW === +1R2 ﾁ
ｳ )uH ｳ ｳ )uH ｳ CAL CAL CAL CAL For ﾁ10n
ﾃﾄｴﾃﾄｴ ﾁ ﾁ ﾃﾄﾄｴﾃﾄｴ 100K 100K 100K 100K
ﾁ 10nｳ ｳ 10n ﾁ ｳ ｳ ｳ ｳ
ｳFor Refｳ 6K8 47K 47K 100K
ｳ ﾀﾄBlackﾄﾄﾄﾄﾄﾄﾄﾄﾄﾁﾄﾄﾄﾁｴﾃﾂｴﾃﾁﾄﾄﾄｴ
ｳ 10n ﾁ 10n ｳ
ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄRedﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ
____ o
12V>ﾂﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄWhiteﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾂﾄｴ7810ﾃﾄo<ﾄﾄﾄﾂﾄﾄ>
=== 10n ===ﾀﾄﾂﾄﾄﾙ 10n=== Lamp
ﾁ 47uﾀﾄﾄﾄﾁﾄﾄﾄﾄﾄﾂﾄﾄﾄﾙ
ﾁ
HI Q ROLLER COASTER
Unfortunately this large 1500W QRO ATU flashed over & caught fire (smells of
burning), due to poor design of the QRO roller coaster coil mounting brackets,
flammable construction fibre board, & inexperienced user (me) when tuning up
with only 400 Watts.
On the back coil insulator combs, there are 3 right angle brackets, that have
sharp corners only a few mm away from the "RF HOT" top of the tuned circuit, &
are mounted on flammable thick fibre glass board.
_______________________1 of 3 Fiber Glass
ｳ ｺo o Combe Support Bars
(ｳ ｺ]____________________
Flammable(ｳ ｺ] RFｳｳｳｳｳｳｳｳｳｳｳ Contact
Fibre ｳ ｳ HOTｳｳSilver Plated ======H===ﾛ= Wheel Rod
Board ｳ ｳ ENDｳｳFlat Coil Spiral Wheel ﾛ
ｳ ｳ OFｳｳｳｳｳｳｳｳｳｳｳﾜﾜﾜﾜﾜﾜﾜﾜﾜﾜﾜﾜﾜﾜﾜﾜﾜﾛﾜﾜﾜAxil
ｳ ｳCOILｳｳｳｳｳｳｳｳｳｳｳ
ｳ ﾃﾄﾄﾄﾄﾁﾁﾁﾁﾁﾁﾁﾁﾁﾁﾁﾄﾄﾄﾄﾄ Flammable
"L" ｳ ｺo_o_________________ Support
Bracket ｳ ﾇﾄﾄﾄﾄﾂﾂﾂﾂﾂﾂﾂﾂﾂﾂﾂﾄﾄﾄﾄﾄ Combe Bars
Screws (ｳ ｺ] /^Sparks
(ｳ ｺ]v Jump Earth
ﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾁﾄﾁﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄChassis
The Caps C1 & C2 are designed for very high voltage & should be the first thing
that arcs over, but not these sharp cornered brackets!
REPAIR
The burnt fibre board & shaped mounting comb strip must be cleaned of any
charred material with a sharp knife. This may mean removal & part disassemble
of the roller coaster support comb bars.
MODIFICATION
To stop reoccurrence at the RF hot ends of the 3 "L" shaped brackets, they were
cut down in length & the redundant nuts & bolts left out of each.
__ ___ __ __ __
Screwｳ ｳ
holes ORIGINAL MODIFIED
ｳ 4 HOLE ｳ 2 HOLE
BRACKET BRACKET
ｳ
Doing this to all 3 brackets (even the top one not near to ground), adds about
1cm to the flashover arc distance! And has no effect on the sturdiness of the
roller coaster assembly as long as the bolts are kept tight.
OTHER BURN MARKS
The 3 combe supports bars can suffer. They are all different with the coil
slots all moved 1/3 of the pitch. But I have managed to reverse the top one so
the burnt RF hot end, is now the cold coil end.
LOOSE SCREWS
As this unit has been used for /P work, some other screws had soon rattled lose
despite locking washer nuts! These have been tightened up & threads painted.
IN USE
The "T" type ATU is easy to use, although it is not quite as good at removing
harmonics as the � (pi) type. But it does an excellent job of protecting the Rx
from DC static, & strong signals on lower bands, that some poorly filtered SDR
Rx can suffer from! (e.g. removing MW Broadcast signals as it is >-18dB for
each frequency halving.)
I use it for /P demonstration stations with a DRAKE L-4B PA or T500M PA & IC735
exciter, on mains or generator.
___________ptt+ALC
_____ ｳ ｳ _________ ______
ｳIC735ﾃﾄﾙ ﾚﾄﾄﾄｿ ﾀﾄｴDRAKE PA ﾃﾄｴ HF ｳ_ oﾄ>1kW Dummy Load
Micﾄｴ 12V ﾃﾄﾄﾄﾄﾄﾄﾄｴATUﾃﾄﾄﾄｴ_________ｳ ｳFilterｳ \oﾄｿ _____
ｳ_____ﾃﾄﾄﾄｿ ｳ ｳ ｳDRAKE PSUｳ ~~~~~~ ｳ ｳ QRO ﾃﾄ>80m Dipole
BatteryﾄｴPSU55ｳ _ｳ_ ｳ___ﾃﾄｿ ~~~~~~~~~ ｳ_ｳ1.5kWﾃﾄ>40m Dipole
~~~~~ ｳBHIｳ _ｳ_ Topband 160m ｳ ATU ﾃﾄ>3el Beam
HeadphonesﾄﾄｴLS ｳ /// long wire aerial ｳ_____ﾆﾍ>G5RV
~~~
The small ATU after the Rig (VECTRONICS VC300LP) can select an internal dummy
load or the long wire. On WARC bands the extra ATU is used to tune out the
DRAKE L-4B linear's bad SWR of its "out of tune" input matching circuits, the
PA output tank circuit matches quite OK.
The HF LP filter is sometimes used to make sure there are no VHF harmonics, if
the station is in a sensitive RF area & "direct no ATU" to aerials may be used.
With the G5RV then the ATU's transformer balanced output is used.
For public demos, a RF proof AF PA is used with mic audio from the AUX socket
of the IC735 & BHI noise reducing LS system, so that both sides of the QSO can
be clearly heard.
* RSGB Radcom Review Article May 2005 P26, & Comparative one to the MFJ 989D
Jan 2007 P30.
See also my Tech buls "HF ATU & SWR Bridge MFJ-904H", "HF ATU & SWR Bridge
VC300LP/QT-1", "Drake TC-3300-LP QRO LP Filter", "Drake WH7 QRO HF SWR Bridge"
& "QRO 1kW HF Metered Dummy Load".
Why don't U send an interesting bul?
73 De John, G8MNY @ GB7CIP
前のメール | 次のメール