Probing around for a powerful 48vdc supply solution I landed on a fair priced Eltek Flatpack2 rack unit. I know, it is an overkill for HAM shack use with its 8kw of DC output power. But as Jeremy Clarkson says; quote “Power and speed solves many things” 🙂
Anyways, this really is a part of a telecom UPS system, and telecom 48vdc system has negative distribution with positive common return rail. This is the opposite of what we HAM usual needs, so it has to be rewired, or re-bared rather.
This is a 2U rack module with a smartpack2 controller and 4 x Flatpack2 2000w HE rectifier units. You can run a single rectifier without the controller but it will default to about 53,5 volts. In order to change the operating output voltage, you need the smartpack2 controller.
With the factory access password, you can with the controller permanently write new settings down to the rectifier, and it will default to any valid voltage value. Of course it is possible to hack and reverse engineer the eltek CAN-bus protocol with other tools. I know the e-bike community has done it.
Here are some pix:
Smartpack2 rack without load fuses cover panel.
Smartpack2 rack unit
Original common positive (+) return bar.
Rewired to common (-) negative return bar.
PowerSuite for M$ windows config and monitoring tool.
This morning I decided to do some work on the good old Kenwood TS-2000.
The MULTI/CH encoder is operating erratic and has getting worse lately. I replaced that with new one.
Replaced the 144MHz UHF-type antenna connector with a N-type jack.
Installed the 1.2GHz Tx Distortion mod/fix by VE2ZAZ
I’ve got these cheap but good working wireless headphones branded Welltech 40699/FKH51a.
After several years of use the two AAA NiMH Rechargeable Batteries dies and I replace them with new ones. But hey, they will not recharge, what is wrong? Having a closer look at the headphones I discover that the battery cases have a protective device to prevent non-rechargeable batteries getting charged. This device is a simple contact spring that has to be grounded to the battery minus potential to enable recharging. So the solution was to remove some of the insulation material at the bottom of the batteries, and now the headphones again are recharging the batteries.
I have also done a small modification to the base unit. I have removed the small internal wire antenna and fed the signal to an external sma connector. This enables use of a better antenna which improves coverage when moving around. A simple antenna for the 850 or 900 Mhz GSM bands works good for this unit which operates on the 860 Mhz LPD band.
Here are some pix…
Battery holder. Upper left: Safety contact spring.
insulation prevents grounding of contact spring.
Bottom insulation removed from battery.
Modified battery on the right
External antenna connector mod
Opened up the ft-1000d today and discovered that the famous w8ji noise blanker modification was missing. Well, no need to dwell. Fired up the soldering iron, picked up three 1n4148’s and a 10k resistor and started to work the mod. And the modification went smooth as oil. The process can be seen in pictures below. I’m not going to discuss the technical detail of this mod, for this information please visit w8ji and n1eu. Oh yes, another thing I discovered was that the rig had the inrad roofing filter mod already installed, that was a nice surprise!
IF board area where the mod is going to be applyed
Connectors in the right corner removed for easier access.
Soldering diodes to connector J2001.
10k resistor soldered to ground lug and third diode soldered to TP2001.