Communicating With Satellites Like It’s 1957

When the first artificial satellite, Sputnik, was put into orbit around Earth, anyone in the path of the satellite could receive the beeps transmitted by the satellite provided they had some simple radio equipment. Of course, there was no two-way communication with this satellite, and it only lasted a few weeks before its batteries died. Here in the future, though, there are many more satellites in orbit and a few are specifically meant for ham radio operators. And, like the ’50s, it doesn’t take too much specialized equipment to communicate with them, although now that communication can be two-way.

The first step in this guide by [W2PAK] is to know where these satellites are in the sky. The simplest way to do that is to use a smartphone app called GoSatWatch and, when configured for a specific location, shows the satellites currently overhead. After that it’s time to break out the radio gear, which can be surprisingly inexpensive. A dual-band handheld is required since satellite uplink and downlink can be on different bands, and the antenna can be made from simple parts as well as [W2PAK] demonstrates in a separate video. Combined, this can easily be done for less than $100. [W2PAK] also goes over the proper format and etiquette for a satellite contact as well, so a new operator can pick it up quickly.

Using satellites as repeaters opens up a lot of capabilities when compared to terrestrial communications. Especially for operators with entry-level licenses who are restricted to mostly VHF and UHF, it adds a challenge as well as significantly increased range compared to ground-based repeaters and line-of-sight communications. There are plenty of activities around satellites that don’t require a license at all, too, like this project which downloads weather imagery from weather satellites.

 

 

Inside A Vintage Oven Controlled Crystal Oscillator

Crystal oscillators are incredibly useful components, but they come with one little snag: their oscillation is temperature-dependent. For many applications the relatively small deviation is not a problem, but especially for precision instruments this is a deal breaker. Enter the oven controlled crystal oscillator, or OCXO. These do basically what it says on the tin, but what’s inside them? [Kerry Wong] took apart a vintage Toyocom TCO-627VC 10 MHz OCXO, revealing a lot more complexity than one might assume.

Inside the insulated enclosure there is of course the crystal oscillator itself, which has a heating coil wrapped around it. Of note is that other OCXOs that [Kerry] took apart had more insulation, as well as other ways of providing the thermal energy. In this particular unit a thermistor is attached to the crystal’s metal case to measure its temperature and provide feedback to the heating circuit. The ICs on the PCB are hard to identify due to the conformal coating, but at least one appears to be a 74LS00, alongside a 78L05 voltage regulator which reduces the 12V input voltage.

As an older OCXO it probably is a lot chunkier than newer units, but the basic principle remains the same, with a heating loop that ensures that the crystal inside the unit remains at the same temperature.

 

 

Nieuw bestuur A23

Donderdag 30 januari 2025 vond de jaarvergadering van onze afdeling plaats. Daarbij waren twee bestuursleden van het VRZA bestuur aanwezig, namelijk Ron Goossen, PB0ANL en Freek Liefhebber, PD3FCA.

Het centrale thema van deze vergadering was het voortbestaan van onze afdeling. Er hadden zich geen kandidaten gemeld en het zag er aanvankelijk niet erg hoopvol uit.

Maar we zijn verheugd te melden, dat er toch een bestuur kon worden gevormd. De vergadering heeft zich unaniem achter het nieuwe bestuur geschaard.

De nieuwe bestuursleden zijn:

Voorzitter: Guido Reijntjens, PA4GR

Penningmeester: Mark Vroomen, PC9DB

Secretaris: Henk Schanssema, PA2S

Dinsdag 4 februari a.s. komen de nieuwe en afgetreden bestuurleden bijeen voor de overdracht.

Wij danken de aanwezige leden voor het vertrouwen. Ook zijn wij veel dank verschuldigd aan VRZA bestuursleden Ron en Freek, die de moeite namen om van “boven de rivieren” de reis naar Zuid-Limburg te maken. Hun aanwezigheid heeft zeker bijgedragen aan het bereikte resultaat!

Tevens danken wij het de afgetreden bestuursleden voor het vele werk, dat voor de afdeling is verricht.

Met vriendelijke groet,

Namens het bestuur van de VRZA afdeling Zuid-Limburg,

Thijs Has, PE1RLN

Henk Schanssema PA2S