Sunday, January 29, 2012

Doodle Labs DL435-30 Reports

A few hams have bought the Doodle Labs DL-435-30 transceiver.

The radio is capable of about 6 Mbps of data throughput utilizing a 5 MHz wide channel in the under-used 420-440 MHz ATV sub-band.

These were first made available in November 2011, so tests have been somewhat limited. However here are some initial conclusions:

At 20-30 feet using a 6 dBi gain omnidirectional antenna a couple different ham groups have seen 1/2 mile to 3/4 of a mile usable non-line of site mobile coverage using a 1/4 wave mag mount antenna. Both reports were in moderate to heavily mature tree neighborhoods.

Keep in mind at this low of a frequency, the height of the antenna will play a role to clear the large Fresnel zone and improve the performance.

The fact that you are not competing with your next door neighbors WiFi, makes these boards great for HSMM. If you can find a few hams in your area interested in it, there are bunch of possibility's for an OLSR network built on these things. Eliminating internet costs at repeater sites, repeater linking etc.

I'd appreciate hearing from other hams who are experimenting with this board wishing to share their reports.

Here is a short video that Kyle, N0KEW made:

Saturday, January 21, 2012

Minitor IV in the Ham Band

Our club repeater is capable of two-tone paging. It uses a CAT-1000 controller.

Many moons ago in the mid 90's we had some Minitor I's pagers re-crystaled for the repeater.

With narrow-banding affecting all public safety channels there will be scads of Minitor III and IV pagers out there, hopefully for cheap.

The municipalities will likely upgrade to the Minitor V as it's narrow band capable.

While the III and IV are frequency programmable, the ones that will be coming out of service will mostly be the 151-159 MHz subband (B) versions. My model: A03KUS9239BC

Never fear, if you use the engineer login function of the pager programming software, you can edit the engineering data, and change it to a 143-150 MHz (A) bandsplit.  (the password is "Taipei")

As for the versions 159-167 and 167-174 I don't think these will lock down in the ham band.

This message thread on radioreference gives you good info in making your own Minitor Programmer. It gives you the pinout diagrams for the Minitors III, IV and V.

When I get a chance to test the sensitivity more in-depth I will edit this page with the results, and mods that I may deem necessary to improve the sensitivity.

{Update}
Sensitivity is good. Near .4 uV



I haven't been able to track down a service manual, but this explains what to do if yours is not locking.


I have had success programming both M3 & M4's for ham freqs.