99.5% of the people who built at least one K1 enjoyed doing so and I am no exception. This article summarizes my K1 building experience hoping that other prospective K1 builderswill find it useful.
The Elecraft K1 is a small multiband CW transceiver kit with 7 watts of output, full QSK, variable IF width, audio derived AGC, and built-in antenna tuner. I have built mine for the 40, 30, 20, and 17 meter bands during the spring in 2006. Be sure to check out my pictures of the K1.
Some Thoughts About the K1
Doing some last minute QSO with the K1 before I head back to CPH. It was a rather joyful weekend with good test conditions of the K1. When the K1 gets back to the lab I’ll have following points on my TODO list:
Great Success with the K1
Today I made some more QSOs using the K1. Here are a few examples:
At 09:05 UTC I called EA6NB, Jim, on 10.108 MHz. He returned my call with 549, but then he lost me. The band was indeed strange with a lots of QSB.
On the Air with the K1
My K1 had a rather turbulent start in its career, I must admit. Somehow I managed to blow the final twice before it actually got on the air. Shame on me!
First Signals in the K1
It’s quite late and I really should have gone to bed but I simply couldn’t resist to turning on the K1.
K1 Problem Diagnostics
It’s been quite long since I last looked at the K1. To tell you the truth, I’ve been very busy with work and gpredict. But now it’s time to fix the K1 and get it on the air before the summer is over.
Elecracft K1 Resources
This page gathers some useful reference material about the Elecraft K1.
- The K1 pages at Elecraft
- Local copy of the K1 docs (versions applicable to my model)
- The K1 data sheet
- The K1 quick reference card
- The K1 assembly manual rev F and corresponding errata sheet
- The KFL1-2 two-band filter board assembly instructions rev H.
- The KFL1-4 four-band filter board assembly instructions rev A and corresponding errata sheet.
- The KAT1 automatic antenna tuner assembly manual rev C and corresponding errata sheet.
- The KNB1 noise blanker assembly manual rev C and corresponding errata sheet.
- Tom N0SS has a lots of usefull stuff for the K1.
- K1 reviews at eHam.
Elecracft K1 Multi-Band CW Transceiver
Small BoomBox and mojo to go… This is how NN6CW and many others describe the K1 – a small, lightwiegth QRP transceiver kit from Elecraft. The K1 has been a legend ever since it came out. It is easy to build, looks very professional, has a superb user interface, and offers great perfomance.
New Final for the K1
I have now waited more than two weeks for the 2SC1969 that I have ordered from El Supply. Since the Easter holidays are coming closer and closer and I want to have the K1 with me, I looked for another source. I found Brinck Elektronik who has a shop in Copenhagen city. I was lucky enough to get the last piece they had on stock. They can still order it for me later but it will cost twice as much.
K1 TX Signal Tracing
Yesterday I have done the transmitter signal tracing using my Velleman PCS500 pc-based oscilloscope. Here are the results:
PRE (0.04-0.09) 0.025 V
ATTN (0.02-0.05) 0.047 V
OSC (0.01-0.04) 0.019 V
MIX (0.1-0.2) 0.042 V
BUF (1.5-2.0) 1.74 V
TR1 (0.5-1.0) 0.66 V
BPF (0.5-1.0) 0.78 V
TR2 (0.5-1.0) 0.72 V
TR3 (<0.01) 1.5 mV
DRV (0.9-1.6) 3.7 V
PA (10-15) 0 V
ANT (10-12) 0 V
RFD (1.7-2.0) 0 VDC
That was enough to convince me that it the the PA stage that is doing something wrong. I took the chance and cut Q7 out and it was indeed dead. I couldn’t measure any BE/BC resistance in any direction and the hfe was 0, too.
First I wanted to order replacements from Elecraft but the postage and Danish VAT would have made it 4 times as much as the price of the transistors. Instead I ordered two of them from the Danish El Supply together with some 1.5 and 2.0 amp fuses 😉
Unfortunately, El Supply did not have them on stock so I will have to wait about two weeks. Well, I can concentrate on other projects in the meantime.