Repairing a Sennheiser freePORT radio mic

The Sennheiser freePORT radio microphone was a very popular vocal mic, being inexpensive and good quality. It is very much at the budget end of the Sennheiser range and doesn’t have all the fancy features of the more expensive models but still does a solid job.

We have a couple of these at our church which we use for portable use and they get quite a lot of abuse. One of them recently broke so I had a look at it, always being keen to repair rather than replace. The handset had got bashed and there was no audio coming through.

One difficulty with these mics is that it’s not obvious how to get into them. The best place to start it by unscrewing the top of the handset to expose the capsule:

The problem here is pretty obvious, in that one of (very thin) wires which runs from the capsule into the body of the mic has broken off. So a repair should be a simple matter of resoldering it, although there is no slack available here so the whole wire needs to be replaced.

The next thing to do is to remove a screw in the battery compartment, and the collar at the top which fits on to the pop shield:

Then you have to remove the shiny black plastic piece which says ‘Sennheiser Freeport’ and covers the electronics. This is much easier if you remove the collar as well:

I ended up replacing both of the wires on the right hand side of the picture by desoldering them from the board and replacing them with new. The wires are very fine, and I used two cores from a burglar alarm cable which were the thinnest thing I could find. You have to thread them through the collar to get to the capsule. The black wire goes to the pad marked with a blue dot on the capsule. Once done it’s a fairly simple matter of putting it all back together again.

The other problem I have had with these mics is that the power connector on the receiver tends to get worn out. This is also dead easy to replace. So with relatively little effort you can keep this working in spite of some quite rough handling.

 

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More Texecom Updates

There have been a couple more interesting updates lately.

Firstly there has been another minor firmware upgrade to v4.02:

I think that this is the last of the v4 upgrades, and it adds some features to do with tamper monitoring for the SmartCom unit and some changes to the translations. I’ve still not updated to 4.01 yet so probably time for a change, although in reality I probably won’t notice any difference.

The other news is that there is now an Android version of the Texecom Connect app:

This looks really nice and is a big improvement over the previous efforts, which I never really got working properly. However I can’t use it without getting a SmartCom in… which I really need to do.

It’s great to see that Texecom are developing the products still, and they have also rationalised the panel lineup as well and removed a lot of the integrated wireless panels. I’m looking forward to seeing what comes next.

Texecom release v4.01 firmware

Texecom have now released a minor update to the v4 firmware to v4.01.

I’ve not seen any specific release notes although from what is mentioned on the website it looks like mainly bugfixes and minor changes.

I’m not sure it’s really worth the effort of reflashing at the moment but I may do if I get an opportunity. I  need to do some maintenance on it as several of the USB serial devices have broken (note to self, avoid bargain basement serial interfaces!) and I want to replace them with a small USB hub and other devices.

I’m still contemplating getting some of the new kit in for review although not done as yet… maybe something for the New Year!

Choosing LED Bulbs

Although I’m keen on saving energy (hence the heating control project) I’ve never been much impressed with the various kinds of light bulbs that have come along purporting to be the energy-saving solution.

The first era was the compact fluorescent lamp:

There are loads of different types of these, as shown above. The earlier ones were straight (top left) and then there were various spiral designs. Although these clearly used a lot less power than old fashioned incandescent bulbs I didn’t like the colour of the light, and I particularly didn’t like the fact they took quite a few seconds to come on. Also of course you can’t use them with dimmer switches, and they don’t play well with the various home automation switches that I’ve been using.

More recently bulbs based on LEDs have been coming in. They have been around for a while but initially were quite expensive and couldn’t be used with dimmers. Also the colour of these was also a bit variable.

What has really prompted me to look at this properly has been the fact that it is increasingly difficult and more expensive to get hold of incandescent bulbs (around £1.50 each or more), and also the ones you get seem to last no time at all. I’m sure in the past they used to last for ages… but now seems only a few months at a time.

We have a lot of chandelier / candelabra light fittings, each of which uses at least 5 candle bulbs. These seem to be blowing all the time and not only does this lead to a dimly lit room it feels like it’s costing me a lot of money.

So I thought it was time finally to address the issue. It seems the market has moved on a lot since I last looked. I wasn’t keen on the ‘no name’ Chinese import brands and I also didn’t really like the ‘frosted’ look of the bulbs. Whilst you can find ‘filament’ style ones these are quite low wattage.

After a lot of digging around I finally found the Philips Master LED DiamondSpark:

There’s a lot to like about these – they are dimmable, they look good and in many ways resemble a real bulb (with the ‘DiamondSpark’ filament), and they weren’t very expensive. I got the 6W version from ledbulbs.co.uk whom I’d really recommend, and they were £4.50 each and actually cheaper because I bought a load of them plus had a discount code.

I wasn’t quite sure what to expect, but the results are really good – indistinguishable to my eyes from the candle bulbs they replaced, and the whole fitting now consumes less energy than a single one of the incandescent bulbs in it before. Also and just as importantly they work well with the Fibaro Z-Wave dimmers that I have scattered around. This is true for both the older v1 and new v2 versions, and I haven’t needed a dimmer bypass because the fittings have enough bulbs to be above the minimum load of 25W.

So all in all I’m very impressed and am glad to have finally made the switch. I’m hoping it will save time and money, especially given the bulbs are rated at 25,000 hours each!

Repairing a Miele Dishwasher

I’ve always been keen on buying quality stuff where I can because it tends to last much longer and give better results. This applies to white goods just as much as anything else. I have had bad experiences with buying cheap washing machines etc in the past and so I now buy the high quality although expensive German brands – Siemens, Miele etc. This has worked out well so far and I’ve had years of good service from them.

The dishwasher I have is a Miele G975 SC Plus which is now pretty old (I bought it about 10 years ago). It has worked pretty much flawlessly all that time although there is one recurrent problem. They use a fan system to dry the dishes (so-called ‘Turbothermic’) with a vent on the front. Sometimes instead of blowing out hot air the fan starts spitting out water which makes a racket and a terrible mess. The reason for this is that there is a hose between the fan unit and the drain which gets blocked up with bits of food. The solution is to strip down the door and clean everything out.

Removing the front panel is a fairly simple matter of removing all the screws from the inside of the door and then various others round the plastic front panel. You also need to pull off the plastic mode selector knob:

Then you can get to the hoses and fan assembly (fan at top left in the picture below). You then have to unscrew and fold down the metal front panel which you can do without disconnecting any of the many wires.

The fan itself can then be unplugged and removed. There is a trick to this – it is held in place not by screws but by a circular grille on the inside of the door. To release it you need to twist the grille and the fan drops out. Be careful doing this or it can drop out unexpectedly.

Then you can dismantle the fan completely and clean out all the muck and old food, as well as cleaning out all the hoses:

It is then a matter of putting it all back together again, and hopefully it will all now work properly. It seems to go for quite a number of years between needing doing again.

I love the fact that these machines are so easy to work on and in my view they are definitely worth the extra money up front.

Repairing a Casiotone 101 synthesiser

As I’ve mentioned in previous posts I am interested in sound engineering and technology, and I love all kinds of music tech although this far outstrips my musical ability. So I’m keen to take any opportunity to get hold of something interesting, even though this often involves working out what to do with it later. I have acquired a number of interesting items this way, some of which I have kept and some I sold on. I still have a Casio VL-Tone VL-1 and I also had a boxed Casio SK-1 although I did sell this one on.

I was at our local rubbish dump the other day, and out of the corner of my eye I saw someone with an obviously old and classic looking synthesiser in the back of the car which was clearly heading for the ‘electrical’ skip. It turned out that this had recently “gone bang” and had been left out in the rain for a few days. The owner was quite happy for me to take it off his hands. On closer examination I found that I had scored a Casiotone CT-101:

I’ve found a few references to this online which are mostly fairly derogatory, and whilst I suppose this is nothing like a Fairlight or even a DX-7 it is still an interesting bit of history, and from a similar era. It dates back to 1981 and must be one of Casio’s first attempts at a professional grade musical instrument. You can see the legacy of the 1970s era ‘home organ’ with the large multi-coloured controls and woodgrain finish. However the sounds are beginning to make the transition from organs to a classic 1980s style synth.

First impressions on getting it home were positive – it’s really well built with a solid wooden case, metal panels and very chunky controls and jack sockets on the back. Unfortunately there is evidence of water damage – mostly to one of wooden end pieces which are chipboard and have absorbed a lot of water leading to swelling and cracking. This is a real shame because this is obviously recent and the rest of it is in good shape.

Given this history of it going bang I didn’t try plugging it but stripped it down to find the problem. The obvious place to start is the power supply, and I was hoping to find a fairly simply fault.

The internal construction is again very well done and surprising simple. The wooden casing is very solid and the PCBs are slotted in to small guides with lots of discrete wiring. There is lots of room inside to work and it’s easy to find your way around. There are a lot of screws to remove at the back and underneath, and the keyboard itself plugs in via a ribbon cable which you can pull out gently from the PCB connector.

A close look at the power supply PSU quickly revealed this:

Most of it looks good but this component (labelled PME 265) has clearly failed. There were bits of it all over the inside of the case, and there was no sign of any other damage anywhere. The damage to the component made it quite hard to see exactly what it was, but after gathering together the broken bits and with a bit of searching around, I found it was a Rifa PME 265 0.02uF capacitor. I think these are used for smoothing / interference suppression in the mains supply.

This specific part is no longer made but a newer version (PME 271) is readily available on ebay. I was able to find a replacement (a PME271) for less than £3. I was surprised by the capacitance rating though, I’ve never seen them measured in Nf before:

The new part is almost identical in size and shape to the old one, and the manufacturer is the same. Replacing it was very easy, just a few screws to release the PCB and I was able to replace it in situ without removing any of the wires by twisting it around and resoldering it. This is the old and new part side by side. No prizes for guessing which is which!

Then it was simply a matter of reassembling and testing.

Then comes the moment of truth… and success! No bangs or smoke, and it works perfectly. I absolutely love the chunky controls (orange and blue toggles and press buttons as seen on the photo above) and the sound is very reminiscent of the early 80s. Now need to think of something to do with it… although looks great in my ‘home studio’!

Lots of new hardware!

After what has been quite a long wait since the original announcement, there is now finally a lot of new Texecom hardware and software released to go with the recent v4 firmware release.

The first of these is the ‘Texecom Connect’ app, which promises a significantly improved user experience over the former apps, which from my experience didn’t work well and were quite basic. The main problem with the app from my point of view is that it is for iOS only… and I don’t have any iOS devices at all. So until an Android version comes out I’m not going to be able to get any further with this.

There is more info about the app (and the rest of the range) here

The other and more interesting products from my perspective are the Texecom Connect hardware interfaces. The most important is the Texecom Connect SmartCom:

I’ve not quite got my head around this yet, but it appears to be provide quite a wide range of capabilities including an ethernet interface (so the same as the COMIP) but also provides an interface with an upcoming range of home automation products. I’m not sure if it interfaces with any other standards (ZWave etc) but it is using Ricochet protocols to communicate with the ‘SmartPlug’ (see below). I’ve been quite impressed with Ricochet for the sensors etc, and this is quite an ambitious move to take hold of the burgeoning home automation market.

The ‘SmartPlug’ as seen above is exactly as the name implies. This is a good start although from my own experiences of HA you really want something which can be ‘stealth’ installed and not lose the manual control. So for a table light it’s all very well switching it through the Texecom app but you also want to be able to switch it by hand. However, the idea of integrating HA with alarm sensors hasn’t been done very much and especially not by mainstream security companies.

What is also good news is that the pricing is a lot more sensible than before, with the SmartCom available for about £75 (from Alert Electrical among others):

Overall I think these are very interesting developments and it’s great to see Texecom developing their products and expanding their functionality. I’m still really interested in being able to use the whole range as part of a bigger HA system and I would love to be able to surface the sensor data into Fhem. I am sure this is possible and I have got some documentation but I will need brush up my programming skills quite significantly first!

I’m looking forward to seeing what else comes out, and maybe at some point I will get some of it in to play with.