OK Gang here's the day one report...Not very interesting I'm afraid...
Major POTENTIAL find of Day 1 - from the schematic and other
instructions:
IF filter caps are same value for all rig variations (15m 17m 20m
30m 40m) but IF frequencies are not the same..... Hmmmmm.
You don't suppose... Naaaahhhh.
Got the box about 4PM Saturday after being out to the Bastrop County
hamfest in the morning, and looking at new pick'um up trucks and
tops in the afternoon... Talk about sticker shock....
Bought the Radio Shack probe out there...Got to test it out....Small fest,
one of those that opens up at 8am and is done by noon....
Background:
Before the box came and in preparation for this joust I pulled all the
old K1BQT articles I could find and reviewed the schematic diagrams
and parts lists and building and tuning instructions....
Here are the articles for those interested:
The QRP Transceiver by Rick Littlefield, K1BQT CQ Sep 90 p43
(This is the basis for the RadioKit rig, same printed ckt board etc.)
An NE602-Based QRP Transceiver for 20-meter CW by Rick Littlefield, K1BQT
Box 114, Barrington, New Hampshire 03825 Ham Radio Jan 89 p9
(This is a three board rig from which the QRP 15 was developed by Rick.
This rig and the one described in the following reference have a 10k
resistor in the base-collector circuit of the TX-RX switching transistor
(a 2N3906) which is not in the QRP 15. The surrounding circuitry is
the same. Almost looks like a typo in the RP 15 article...Hmmmm)
A Compact 20-meter CW transceiver Ham Radio Jun 87 p8
(A 15 watt rig from which Rick developed the QRP 20.)
There were a couple of earlier articles listed in the references section of the
Jun 87 article which may also be of interest.
(Boy, Rick sure is a builder!!)
I found that I sure have a preference for schmatic diagrams which list both
a component ID and the value. It make life so much easier!!
I concentrated on the QRP 15 article and added component IDs and made
complete parts lists and reviewed these and the board layouts and the
building and tuning instructions....
Generated lots of paper and learned some stuff.
Read the Wes Hayward articles on crytal filters in QST May 82 and July 87.
Now for Day one activities....
First order of business upon box arrival was a complete
inventory of everything.
Box Inventory: (OH Boy... lots of bit and pieces.. The box is 7 x 9 1/4 x 12 inches
and had four dollars postage on it.)
Manila folder with manual and misc notes not all of which I have fully digested..
(One would not confuse this with a Heathkit instruction manual.. :-) )
White box 3 1/2 x 6 1/2 x 7 1/2 inches containig board and attached parts in
an anti-static bag.
Bag of 11 xtals - 5 - 12.000mhz and 6 - 6.0000mhz
5 x 8 1/2 sheet of paper with some caps taped on and labeled.
5 x 8 1/2 sheet of paper with some resistors, diodes, and choke taped on and labeled.
5 x 8 1/2 sheet of paper with some wire taped on it and labeled.
5 x 8 1/2 sheet of paper with some wire taped on it and labeled.
(it is obvious from the markings that other parts were on these sheets at one time.)
Four inch piece of 1/2 in PVC with two blue switches mounted, with 3 3/4 ft of cable
and a 1/8 stereo plug on the end... A paddle simulator I guess, wired that way...
2 x 2 1/2 inch pc board stock with uglies on it labeled "xtal osc for checking
freq of xtals - W1FB Design Notebook p181
2 5/8 x 3 1/2 inch pc board stock with pads cut and components labeled "Jig for
testing osc ckts used in RadioKit" (Somebody's been there, done that...
No results notes however.)
Tranceiver case and 2 bags of hardware and misc parts for the case.
Loose parts, some are new and some seem to have already been tried :-) ...
ECG235 NIB
ECG311 NIB
2 - NE602AN in foam
8 pin socket in foam
MC7812C
1K Bourns pot
10K Alpha pot
1K GC pot with switch
MRF479
This looks like a nice little rig if we can get it going.....
This inventory got interrupted by the OUTLAW NATIONALS Tractor Pull
in Austin at the rodeo grounds....NOISE!!! POWER!!! QRO fer sure !!
MONSTER trucks crunching old cars... What people won't pay to see...
Sarah and one of our sons and his wife and some friends (including
John Barleycorn) and I soaked up all this noise and excitement all evening,
which definitely brought out the badgers to see if I was going to continue
the debugging tonight!!! No Virginia not tonight....
Today (Sunday) finished the box inventory.
Performed a comparison of the RadioKit schematic with that of the
CQ article...
Some changes for frequency differences:
Table for 15m 17m 20m 30m and 40m frequency sensative parts.
(Interestingly the caps in the crystal filter are not in the table
even though the IF freq changes with the bands!! Same
value specified for all bands!!! Can this be correct??? I don't see
how it can... Will check the Wes Hayward article in May 82 QST
and the handbook...)
Most variable caps have a fixed padder added to set proper value and
still use same variable cap for all bands. These caps go on the foil side.
The TX driver device varies depending on band:
15,17m - 2N5109, 20m - 2N2219A, 30,40m - 2N2222A
Some changes for function:
Left out the CW pilot indicator circuit (Cost cutting??)
Changed the BFO and TX VXO circuits for "improved shift"
Added 100 ohm resistor to the two 2N3906 emitter circuits.
Changed 6 volt regulators for NE602s to 5 volt units.
Power for external keyer at key jack removed. (Accidently omitted???)
Some changes for ??
Audio coupling cap into LM386 changed from 1uf to 2.2uf.
Audio coupling cap between U3 and audio filter moved from
filter side of switch to U3 side of switch.
Performed a comparison of the QRP 15 article by K1BQT in theRadioKit
manual with that in Sep 90 CQ. Not identical, mostly editorial
changes.. But:
In the Final Alignment section step 4 is omitted. This section had references
to the CW pilot LED, but contained the instructions on how to set up the AGC
threshhold.... Hmmmm
In the Final Alignment section step 5 is omitted. This section defined how
to setup the RIT... More Hmmmmm...
In the Final Alignment section the step on alignment of the 11mhz trap is
lined out. Hmmm again...
Reviewed all the RadioKit documentation and other misc notes from previous
mystics included in the manila envelopment.....
Made some copies of the enlarged parts layout diagram and the enlarged
front and backside bare board diagrams to make notes on..
You never really appreciate a good silkscreen job til you try to work with
BARE boards...
Started inventory of installed parts on the board and inspection of all the
thingies stuck on there....
Next on the list:
Finish Inventory of parts installed on board and all jumper connections.
Figure out if the caps in the xtal filter are correct or need to be changed.
Try to check for solder bridges and other wrong things on the solder side.
Verify the toroid windings on all toroids.
If all the above goes well, attempt the INITIAL TESTING as specified
in the documentation....
Take a walk in the sunshine to ponder life and work off a few calories..
More later....
(I know.. I know... POWER UP!!!! Patience patience... don't want to
fry it all!!)
Larry
By the way how do you wind 1/2 turns on a toroid????
You know like "...1 1/2 turns on the ground end...".
KA5T - Larry Wise - Georgetown, Texas - lewise@inetport.com QRP-L 89
ex: KN8OSG K8OSG(1959-1967 MI) W6HED(1967-1968 Ca) W4ZTB(1968-1978 Fl)
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