| Part
(numbers match the ND2X shematic but can easily be
applied to the others) |
Cost
|
Location |
| Tube |
about
$110.00
|
|
| Tube
Socket |
$125.00
|
We
will build this much improved mounting fixture |
Triode control
board
G3SEK and WD7S |
$135.00
to $159.00
|
(http://www.ifwtech.co.uk/g3sek/boards/triode/triode-3.htm)
http://home.earthlink.net/%7Ewd7s/triode_control.htm
|
Plate choke
- RFC2
1.8-30 MHz Amateur Bands including WARC. Ideal for amplifiers using
811A, 572B, 813, 833, 3-500Z, 8877, 3CX800A7, etc. Used extensively
in the Ameritron and similar Linear Amps. 1.5A, 225 uH, 4 KV max Size:
5 5/8” L x 1” diameter Ceramic coil form Part Number: RFC-3
|
$24.95
|
http://www.rfparts.com/choke.html#plate |
Cathode choke
- RFC1
Bifilar wound, broadband filament chokes. Suitable for 3-500Z, 3-500ZG,
3-1000A, 3CX800A7, 8877, 833, etc. 30A, 1.8 – 30 MHz 6” L x 0.7” OD
Part Number: FILRFC-30.
Note we do NOT need this high current choke.
Only 3 amps needed, not 30. |
$17.95
|
http://www.rfparts.com/choke.html#grounded
Wind this choke from two 48" lengths of #18 wire. These wires should be bifilar wound to fit a 3.5" length of 3/8" ferrite rod. Wind the wire on a metal rod slightly smaller than the 3/8" ferrite rod that the turns will live on.
The single turn cathode choke should be wound the same way with a single 48" length of #18 wire to fit a 1.5" length of 3/8" ferrite rod.
Both chokes will be about 25 to 30 uH. |
| Cathode coupling
caps - C7 & C10 and filament bypass caps C8 & C9 - .01 uf
each @ 300 volts or greater. |
$5
|
- |
Plate coupling
caps - C2
totaling roughly 2200 pf 10 Kv |
$25
|
- |
Plate bypass
caps - C5
totaling roughly 2200 pf 5 Kv |
$15
|
- |
Roller inductor
- L2 & L3
about 30 uh to cover 160 meters |
$85
|
- |
Strap inductor
- L1
A few turns for 10 meters |
-
|
- |
| Turns counter
dial |
$25-$35
|
No longer available from Max - Gain
Systems (Allen Bond) |
| Flexible shaft
couplings (2) |
$8
|
- to allow
for minor misalignment between the roller inductor and the vacuum
variable with their turns counter dials. |
Plate tuning
cap - C1
About 15-500 pf. Low end is limiting
factor. Voltage should be about 2 to 2.5 times plate voltage (7500
v for 3250 v plate. 10 KV to be safe). Vacuum variable
may be the best choice here (Jennings UCS-300-15S Vacuum Capacitor,
15-300 pf, 15KV) Click here for more info. |
$100
|
These are
either hamfest, internet (maybe Ebay), or buddy parts or see Allen Bond at MaxGain Systems |
Loading cap
- C3
About 1500 pf broadcast variable, 4 or 5 sections of 350 pf each works.
Broadcast variables work and at 2000 watts output into 50 ohms you
only see 316 volts. |
$10-$25
|
Old broadcast
variable capacitors are best for this. 4 or 5 sections of 350 pf work
nicely. You can also use a high value vacuum variable for a lot more money. |
Additonal
Loading - C4
1000 pf switched in as needed for 160 meters. |
$10
|
- |
Plate safety
choke - RFC3
2.5 mH to protect you in case plate coupling caps leak or short. |
$8
|
- |
| Knob for loading |
$5
|
- |
Vacuum t/r
relays - K1 & K2
Jennings RJ1A or
Kilovac HC-1. Also needed to switch additional capacitance across
plate tuning for 160 meters and the B2B is a good choice for that. |
$25-$35
|
Several sources.
Max Gain Systems is one.
Compare some of these relays |
| Plate voltage
meter - 5,000 volts - rescaled 50 or 500 ua meter |
$15
|
Meters may
have to be rescaled. Also some may want to use the WD7S bar graph
display instead of meters:
http://wd7s.home.att.net/ds-1.htm
|
| Plate volt
meter multiplier resistors and HV sense for triode board |
$15
|
- |
Plate current
meter - 1.5 amps
rescaled 50 ua |
$15
|
- |
Grid current
/ plate voltage meter - 500 ma / 5,000 volts
rescaled 50 ua |
$15
|
If you only
want 2 meters instead of 3, it is common to use the same meter to
measure grid current as you use for plate voltage |
| Meter switch
and knob |
-
|
- |
Blower - >100
CFM,
<1500 RPM |
$25-75
|
- Grainger
has Dayton 2C647 which is 134 CFM and 1500 RPM for under $50 |
| Filament transformer
- 12.6 VAC @ 3 amps for one tube, 6 amps for two tubes. |
$20
|
-Consider
using a regulated DC supply. NO center tap needed. |
| HV Connectors |
-
|
See Gordon's
comments and link about Millen connectors |
| Control connectors |
-
|
Some like
Molex connectors and others D style connectors. |
| RF Connectors |
-
|
Your choice.
Some recommend different types input and output so they will not get
swapped around. Example: BNC for input, UHF or N for output. |
| Variac for
filament adjustment |
$15
|
Use a 0.5
amp to a 2.5 amp variable transformer here. Some say use a rheostat
in series with the primary but that assumes that your filament voltage
will be high to start with. Not needed if you use a small switching supply. |
| Feed thru
caps for T/R relay box, triode control board box and meters |
$10
|
- |
| LEDs for status
indicators from triode control board |
$10
|
- |
| Various barrier strips to make connections for such things as the filament transformer etc. |
$10 |
- |
| Kanthal-Globar
Resistors |
|
Order desk - 716 286 7610 |