Tuesday, March 30, 2010

Heathkit IP-18 Power Supply Use and Repair





Not being one to read the manual (RTFM) I bought a used IP-18 and tried to use it to charge a gel cel - don't do this!  Q4 will catch on fire!  Q5 will be crispy too! Flames and smoke come out of the case!  Q4/Q5 are 2N3393 which don't seem to be available any longer.  I substituted them with some MPSA06RLRAG somewhat generic NPN amplifier transistors.  The pin-out is different so observe any  change.

As I have two of these units I compared the working and non working voltages and resistances until they were about the same.  Here is the final chart of the 'stock' and the repaired units with Q4/Q5 replaced.

They both seem to be working at this point.

Heath HP-18

Some Voltage and Resistance Readings

Stock Repaired unit

Q3
E .7-16.1 .6-18.1
B 1.1-16.5 1.0-18.6
C 29.2 29.2



D5 + .6 .6
D5 -    .7              .6

#3(open) 20.1 21.1   Terminal Strip shorting bar removed

Q4
E O 0
c 18 1.5-18
b .6 .6


Q5
E .7-16 .6-18.1
C .6-17.1 1.5-19
B .7-16 16.6-16 .6-18 (4.1-18 CURRENT POT)

Q2
E 1.2-16.5 1.0-18.6
C 29.2 26.6
B 1.7-17 1.4-19.4

D3
- 23.9 22.7 OK
+ 19.6 18.0

D4
- .8 3.4
+ 19.3 17.6
ACCROSS 20.1 21.1    OK

Q1
G 1.7-17 1.5-19.2
D 28.6 26.2
S 1.7-17 3.5-21

AC REF
GR-GR 34AC 32AC OK


RESISTANCE
METER ON 200K
Q3
RED TO +
BLK TO

E 0 0
B 4 (VARIES) 4.2 (Varies)
C 22.4 23.4

RED TO -
BLK TO
E 3.5 2.2
B         (VARIES)      (VARIES)
C 23.4 23K (VAR)


Q4
RED TO +
E 3.4 3.4
B 7.4 5.7-11
C 23.4 VARIES UP

Thursday, March 11, 2010

Queen Anne County RACES


At the RACES meeting Certificates of Appriciation were awarded to all members who helped out with the Blizzard.

Ft. Tuthill 80 QRP Pt Two

Was lucky enough to get both a N/O and a N/C pushbutton Switch in the kit.  The N/O, in this case the RED one is the one that works!  Getting ready to wind the coils soon.

Snow Almost Gone




The 1st part of the Week provided us with temps in the 60's and Jack and I took a bit longer walk down the the nature trail near the head waters of the Corsica River a few hundred yards from the house.

Sunday, March 7, 2010

ARRL DX SSB Contest

 Band    QSOs    Pts  Cty
   1.8       1      3    1
   3.5      21      63   19
     7      79     237   51
    14     163     489   69
    21      99     297   44
    28       9      27    7
 Total     372    1116  191
Score: 213,156


eQSL Card from one of the weekend contacts to Sengal West Africa



The DX SSB contest was busy and the Alpha 78 worked for the entire weekend.  The biggest surprise was working KH6 using the Cushcraft R7 on 75M.  The 40-10 vertical antenna is very marginal on 80M but it loads up with the tuner when using a 130 feet feed line.

Friday, March 5, 2010

What is a S.E.M. QRM Eliminator ?


S.E.M QRM Eliminator is a phasing noise reduction device that I am trying out.  May have to make some cables for it and see if I can get it all wired up for the ARRL SSB Contest this weekend.  On a quick test on 80M it took a S8 noise level down to S1 with a bit of adjusting.  It has a T/R relay that needs to be wired up for transmit and a 12V supply line for the circuit.


AN INTERFERENCE CANCELLING SYSTEM FOR YOUR RECEIVER OR TRANSCEIVER


Lloyd Butler VK5BR


(From Articles originally published in Amateur Radio, September 1992, January 1993 and January 1994)

http://users.tpg.com.au/users/ldbutler/NoiseCancelling.htm


AMANDX PRESENTS

 M
FJ 1026 MODIFICATIONS  
 
 This review and the modifications were done by Mark Connelly. 


Another good link on mods on the MFJ 1226 and a bit of history of these type of units

http://74.125.93.132/search?q=cache:HQjJ-YsOZ4gJ:www.radiodx.qsl.br/ESCUTAS/mods%2520mfj1026/Mods%2520MFJ-1026.doc+Sem+qrm+eliminator&cd=45&hl=en&ct=clnk&gl=us

Tuesday, March 2, 2010

Winter Visit to Virginia


Springfield Arms XD-45



Trying out a brand new Springfield Arms XD-45 at the family range with my nephew.

Monday, March 1, 2010

'Car Trouble'


Took the Corvette out for a drive to Northern Virginia to go to the 'Vienna Hamfest' and visit family.  Turning into my son's development near Harpers Ferry. West Virgina the car lost power and I attempted to restart it.  After a min or so of trying I noticed smoke coming from the cargo area behind me.  This was the result.