Archive for April, 2008

Progress

Wednesday, April 2nd, 2008

Last October I was at an event organised in Clifden to commemorate 100 years of Commercial radio. On October the 17th 1907 the worlds first commercial point to point wireless link opened for service between Clifden in Ireland and Glace Bay, Nova Scotia. This link remained in service until the Clifden station was destroyed in 1922
You can read some background on the type of transmitter used at Clifden on
OZ6GH’s pages

I recently came across traffic logs for the first few months of the station’s operation, these show that in the first ten months of operation that 129,614 words were sent and 116,633 words received over the radio link, a total of 246,247 words exchanged, approximately 820 words a day.

Traffic Log Page 1 Traffic Log Page 2

I expect that in the later years of operation that the data rates were much improved but even assuming that 12 words per minute could have been maintained for 18 hours per day, every day, this works out at approximately 331 Megabytes of data transmitted during the entire lifespan of the station

A little over 100 years later my company commissioned a new 155 Mbs wireless point to point link to connect to our Internet transit provider.
331 Megabytes of data can pass over this link in around 17 seconds. This link is just a tiny sliver of today’s telecoms infrastructure. What a long way we have come in the last 100 years.

The Elecraft K3 and an Audio Patchbay

Tuesday, April 1st, 2008

I have had the very nice elecraft K3 here in the shack since November 2007. It’s an absolutely fantastic radio and it also has a lot of I/O connections on it’s crowded rear panel.
Elecraft for user convenience sake make all the audio connections using 1/8″ Jack sockets. This is of course very handy in that using a single standard audio connector makes for quick and easy reconfiguration. Unlike DIN or Mini-din connectors 1/8″ Jack plugs are available almost everywhere too.
The downside is that in a permanent shack setup reaching around to the crowded rear panel may be tricky and with the tight spacing it’s easy to remove or losen the wrong mini-jack plug as they do not have much holding force.

I have made access to the K3’s wide range of I/O connectors much easier by connecting all of the Audio keying and PTT lines via a 1/2 Normalised balanced jack Patchbay.

1/2 Normalised is particularly usefull for this purpose in that you can plug into the upper (black) Socket and be connected in parallel with the normal signal path. if you plug into the Lower socket you interupt the normal signal path.
Parallel connections are usefull if you wish to route the line out audio to two devices, or hook up two Morse keys.
The interupting connection is usefull for connecting a different microphone as you would not want to have 2 microphones connected in parallel

Elecraft K3 with Patchbay

One of the problems with patchbays is keeping track of all the connections. I do this by using a simple wordprocessor table which looks like this (click on image to zoom in)

K3 Patch

As you can see I have plenty of unused inputs for future use.

Patchbays are easily available new or second hand at low cost on e-bay and make a most usefull addition to the shack.

A Blog

Tuesday, April 1st, 2008

Well I resisted Having a blog for a good number of years now, Finally it’s time to give in and follow the herd