Easily Heard Signals


DSC05943I received my converter kit from Down East Microwave, Inc. yesterday. As you can see in the picture it is labelled L144-28INAC. Unfortunately I ordered a L144-28IACK. The difference is the IACK includes the ApolLO synthesizer which is NOT in the kit shown here. I admit I don't completely understand the meaning of the DEMI suffix codes.

The instructions on how to install the ApolLO into the converter are in the package. The ApolLO is pre assembled so it is certainly packaged in a separate component bag.

I had a concern that perhaps the labels were switched between two orders and another ham received the IACK package.

An overnight returned email from DEMI confirms it was a shipping error and the ApolLO is already on its way. No big deal. I am not in immediate need. I do like to make sure I receive my complete order.

I operate a small mail order business myself and have personally made errors such as this one. The annoyance is usually overcome by my immediate action to make a correction. Shit happens. It's how fast you change the diaper that restores contentment.

Thanks to positive action from Sandra, DEMI is NOT on my "S" list... :)


DSC05891 I am playing with options for a 10 MHz standard and stable frequency reference for the microwave build. There is quite a range of options. One thing there isn’t is an off the shelf, reasonably priced and easy to use portable standard. That’s a lot of requirements in one sentence.

Now if I could just find some cesium, I could build the ultimate atomic standard. NOT! The closest is a rubidium gas frequency standard, but it has faults (high current, long warmup) as far as being easily portable. Very popular today is using a GPS receiver to stabilize a more earthly standard. But GPS needs to have a location for its antenna to see the sky and hear the satellites.

 57I decided to home my efforts to a heated oven (temperature) controlled crystal oscillator OCXO. It takes a while to warm up and stabilize but it is portable. I have ordered several OCXO modules from EBay. These items are not plug and play, but can be the basis for building what I need. The first one I have in hand is shown in the first picture and I just saw another one in the NTMS reflector that I ordered today, 2nd picture. It may be a month away as it is sourced from China.

All subject to change of course, as I have not started any construction. I just like the planning as much as the doing, and throwing my ideas on the table for review.

UPDATE: The second OCXO was shipped the same day it was ordered... on potentially the slow boat from China. Results can vary, but I'll post a note when it arrives. I also received notice that my DEMI L144-28IACK shipped today from Florida.

10 to 2 Xverter Update

I have been playing email tag with Sandra K4SME at Down East Microwave (DEMI) for a few days. My initial order for a L144-28INCK was over 25 days old. Sandra said I was sent an email about the delay, however I never saw it. Not unusual as I receive 100's of Spam because of my exposed email. I use a service, pobox.com to filter all my email. It filters out several hundred per day. Couldn't live without it.

The good thing is the delay started a conversation between Sandra and myself about exactly what I needed. I had changed my original plan and purchased the FLEX-1500 for my front end transceiver. This was after I first placed the order for the L144-28INCK that has a built in 116 MHz LO. No external 10 MHz standard required.

The Flex-1500 has the provision to be used with an external 10 MHz standard. A far better method for using the radio far into the microwave regions of the spectrum. The best microwave design has all stages tied to one standard 10 MHz stable master reference.

Sandra told me DEMI has a version of what I ordered with the built in ApolLO synthesizer, but it is not listed on the website.

I realized what I really want NOW is the L144-28IACK converter. It is the same as my original ordered unit with the ApolLO synthesizer built in. It requires the 10 MHz external standard.

That changed my thinking that I could convert my original L144-28INCK to an external 10 MHz at a later date. I wasn't sure how that would be done. Today I did find a Design Note on the DEMI site on how it's done. DEMi already had the plan. I would end up with the L144-28IACK, but would need to tear apart the INCK version to install it.

Sandra's great customer service revealed to me my thinking was a bit newbie short-sighted. She never SAID that. Ha! I came to my own conclusion. She was just making sure I ordered what I really wanted, thus meeting my expectations. What Sandra had actually done was taken the time to read this blog and realized I may be a bit off track. I was. Her guidance was very welcome.

Because of the delay, it was NOT too late change the order. So I have. The cost went up of course and DEMI has a better sale, but a much appreciative new customer. Thanks to Sandra, K4SME.

OK, so where is the L144-28IACK? ...It's coming. :)