DSP-10 Part Buying Information
NOTE: As of January 2018, I am trying to make some of this material more useful!! Part of this is to remove out-of-date and 404 links. The part source references have been removed for that reason. RSL
Rich Kellner, W5RXP, put the parts
list onto an Excel spread sheet. This is handy for tracking the prices
as well as an aid for placing orders with the various suppliers.
I have edited the list some, where I had information that Rich had not
yet located. If there are any errors, I probably was the one that
introduced them! In any event, you are on your own in using this data.
Check it over and make sure that it is doing what you expect when
you order something!
The spread sheet was revised 27 Oct 99. It now includes all the parts for the box, as well as the board. Check the revision notes at the bottom for details. Please note that this data is not the result of a lot of price shopping. It represents reasonable sources, but not necessarily the best. Send me feedback, if you find better sources, and I will attempt to get them posted.
The data is available here in HTML. If you have a real need for this data in Excel .XLS format, send an email and I will get it for you. This saves me work in that I am only putting corrections onto the HTML version. Further update - changes that I am aware of to 12 June 00 are now in the HTML version. RSL
Spread Sheet in HTML
is the same data as the spread sheet, but you can
read it with the columns lined up on your browser. It cannot be loaded into a
spread-sheet program, but it does have the information needed as an aid
to buying.
Tab separated text format,
suitable for loading into most
spread-sheet programs. Note that you will need to play with column widths quite
a bit, as this information is not in the file. This file is up to 10 Nov 99.
See the HTML Spread Sheet for later changes.
More General Parts Info:
C71 TEMPERATURE COEFFICIENT The wrong temperature coefficient was specified for C71. If your second conversion PLL does not work properly as it warms up (check the tuning voltage at the junction of C62 and R54), yours is not an NPO. The correct part is Digi-Key PCC221CGCT-ND, which is 0805 size. D-K does not list a 1206 (bigger) size. Mouser lists the 1206 size as 140-CC502N221J. I have not tried these, but they should be fine and are now shown on the spread sheet.
If you have access to any 220 PF NPO put it in there. There is a reasonable amount of space in the area around C71, and so a leaded cap would work. The little "via" by the one end of C71 is ground, if that helps. You should not need to remove the board from its mountings.
C220 and C221: Oct QST shows these as surface mount, but they really need radial leads. It also wouldn't hurt to get some margin on the Voltage. I would suggest 47 uF at 25+ Volts, like Mouser 140-XRL25V47 or Radio Shack 272-1027. 28 Oct
J208 8-Pin DIN: The part number was not listed. Radio Shack does not have this one. I got mine from Digi-Key, CP-1280. Interestingly, Radio Shack sells the mating plug, 274-026. 28 Oct
SPACER LENGTH: I would sugget you lower the main PCB and the EZ-Kit both by making the spacer under the boards 3/16 inch (5 mm) instead of the 1/4 inch listed in Fig 11. These can be aluminum if you stick these to the boards with a TINY spot of RTV. I used Digi-Key J166. 28 Oct
HSMP-3804's Tony, KE4ATO, indicated that diodes D1 and D2, HSMP-3804, may be available from Newark, P/N 83F5593.
IMPORTANT CORRECTION: Two of the values of chip cap, the 470 pF and the 0.01 uF
have pads on the board for 0805 size parts. I have been telling people that they can use
the 1206 size. This is problematic, since inspection becomes very difficult. Please use
the 0805 size for these two values. They are all bypass caps and can be 10 or 20%,
and any ceramic types (Z5U, X7R, etc.)
The supplier part numbers now on the spread sheet, for the 0805 parts, are:
470 pF: C9,...,C136 Digi-Key PCC471BNCT
0.01 uF: C7,...,C142 Mouser 140-CC501Z103M
Both values can be bought from either supplier. Check their catalogs.
Surface Mount (SMT) Inductors
The 32CS SMT inductors, listed in the original parts list, are being phased out by
Toko. Some values are still available from Digi-Key, others may not be. One
alternative is the API-Delevan Series 1210 Unshielded inductors, also
available from Digi-Key.
I bought some of each of the five values used in the DSP-10 and tested them.
The differences were measureable, but not big. For the DSP-10 I feel that
the API-Delevan parts should work fine. The biggest drawback for the
API-Delevan parts is that their values are NOT marked on the case. We have
lived with this situation on the caps, but it does require extra care.
Soldering, size, and ruggedness all seem fine. The API-Delevan parts are less
expensive. RSL 19 Apr 01, posted here 5 Sept 01.
Rough cost estimates for small quantities are: EZ-KIT $90, RF PCB $45, Parts for RF PCB $170, Box and Connectors $90. 28 Oct 99
The question comes up as to the suitability of low-cost computer crystals that are widely available for 10 MHz. First, I would not hesitate to put one in if you do not have a high quality crystal available. The problems that you can expect are temperature stability and the initial frequency setting. The frequency can adjusted with C110 along with a change in C109 value (more capacity is a lower frequency of oscillation.) But, the temperature stability can be anything with the cheap crystals. You can't do much about it without changing crystals.
An update on low-cost crystals:
As an experiment, I put one of the Epson CA-301 10 MHz crystals in at Y101.
The potential advantages are their available from Digi-Key (Part No SE3420)
and cost of only $1.17.
The CA-301 oscillated fine. I was able to put it on frequency at room temperature by placing 10 pF leaded capacitors across both C108 and C109 (in addition to the caps that are already there). I warmed it up to 35 deg C and measured the 2-meter frequency change as 58 Hz per deg C. This suggests that you could keep the 2-meter frequency within +/- 600 Hz, over a 20 deg range, which is certainly useable. Remember this is a sample of 1 and that they are spec'd rather loosely. But experience with the CA-301's has generally suggested they are better quality than most 'computer' crystals. Bob W7PUA, 18 Dec 99.
Motorola MC145170D2 PLL Motorola upgraded the part to revision 2. This changes the part number for U7 to MC145170D2. You do NOT want the same part ending in DT2 as this is the package with 0.025 inch pin spacing---very tight! If you have MC145170D1 it will work fine (they are what I used.)
This was last revised 20January18. Bob Larkin, W7PUA