Dr8ton

Forgot about this post: Reversing the washer did not resolve the problem so I fitted a new pump. The washer idea might work for others though... Dr8ton

Good morning Pete, Yes - the wall plates are the old style ones. I'll fit modern ones as you suggest. I've got loads of F connectors. Cheers for the cable link. Dr8ton

Hi Pete, The 2-way splitter is passive. On my mooring with 25% gain and the antenna slightly raised it is possible to have the radio and TV on together with no static or picture break-up (with less than 25% gain I get zip, except if I raise the antenna). Unexpectedly, with the radio on standby or even unplugged I still need about 25% gain for the telly - not sure why. Anyway at 25 mA, winding up the gain is no problem so on the mooring it's good. But what about on the move? Well after a quick read of your links (brilliant!) I am learning that there might be a few ways to compensate for signal loss should the gain controller + antenna extension fail to cope: 1. Use lower loss cable - I think mine is "type C" with a solid dielectric but I'll check when aboard 2. Reduce the cable length between the antenna and the gain controller to about 15 feet (all I need) 3. Plug the antenna directly into the gain controller (at present there is a coax wall plate in-between) Also, should on-board interference become an issue, I can replace the boat's "pre-existing" coaxial wall plates: between the antenna and gain controller, between the gain controller and TV and between the splitter and radio. When the signal is too strong I will simply wind gain off manually (the amp is not automatic so won't work with an attenuator???). Thanks, Dr8ton

Thanks a lot Nick for answering all my questions. You have explained the observed difference in signal strength when I plug the antenna directly into the TV. Also very useful to learn that the gain controller draw is nominal even on full gain. This means I don't have to worry about a bypass. Best, Dr8ton

The following is my recently fitted Narrowboat TV and radio solution (12 volt supply): A single omnidirectional Glomex antenna feeds a Meos TV and Kenwood car radio at the same time with gain added (via a Glomex gain controller) when reception is difficult or if I can't raise the antenna sufficiently. Questions: Does signal strength reduce each time a coaxial cable is joined? I have 4 joins on mine. Does signal strength reduce significantly with a longer coaxial cable run? Mine is about 60 feet. Roughly how much of the signal is leaked by the coaxial connectors and is it worth buying only gold plated ones? Does it matter much that we have joined 75 Ohm cable to a very short run of inaccessible "pre-existing" (brown) coaxial cable from the boat's analogue TV days? How any mA (typically and very approximately) will my 12V Glomex gain controller draw on full gain? The tech. spec. cites 25 mA but for what I don't know (the gain controller model number is at the end of this post). If you want the background read on....... Thanks, Dr8ton The Glomex omnidirectional antenna is on an extending pole mounted on the outside of my cratch board. Seventy five Ohm cable carries the signal (via a 2-way cable splitter) to a Meos combi TV and to a Kenwood car radio. The total cable run is about 60 feet (though roughly 45 feet is currently coiled up so I can move the antenna about for testing purposes). On the antenna side of the splitter is a 12V Glomex gain controller. Note that my gain controller does not have a by-pass built in so it must be switched on to receive a radio and/or a TV signal. Yesterday I tested the finished system with the boat static on her mooring in a good reception area. After raising and lowering the antenna and messing about with the controller (e.g with the antenna lowered to cabin roof height I need to add about 25% gain) I got a strong signal on all Freeview channels and excellent FM from the radio, even at the same time. Then, as an experiment to test the effect of the cable joins, I simply plugged the Glomex antenna directly into the TV. I found I could lower the antenna completely and even bring it inside the cratch with no significant loss in signal quality. So on the mooring at least I do have this option (i.e. after rigging a gain controller bypass for convenience). That said, my simple experiment suggests that splitting the cable (e.g. to incorporate the gain controller) reduces signal quality. To compensate I wound up the gain (at the expense of mA). Of course this wasn't the point of fitting the gain controller! It's main function will be to help improve poor reception "on the move". Even so, I can't help wondering if splitting the cable to accommodate a gain controller is counter-intuitive, at least in part..... Equipment used: Antenna: Glomex V9125 12/24V Gain controller: Glomex 50023 / 98EC (with on / off switch wired to 12V panel) Cable: 75 Ohm (supplied by Glomex as part of kit) Two-way splitter: Glomex V9147 Coaxial connectors: F type TV: 19" Meos TV/DVD combi 192B (plugged into 12V DC socket) Radio: Kenwood Radio/CD/Aux KDC 24

Many thanks for all the input. It's very much appreciated. I managed to get hold of an Alde engineer today. The top washer on the circulation pump (the one the expansion bottle cap tightens on to) is made out of EPDM. These washers commonly sag with age. When that happens the pump drops a little so the gap between the impellor and the bottom of the well that it sits in becomes compromised. Then, when the washer is thin enough due to age, hotter water further increases its tendency to sag. Solution? Reverse the washer! I am back on the boat this Friday and I'll give it a go. Immediately afterwards I am away, so I'll let you know how I got on when I return to the UK in July. Apparently, for those wondering, the best place to buy the washer (in case one turns out to be needed) is Midland Chandlers. Jo_: At some point I will need to do a gas appliance test.There are a few Alde approved service engineers who do boat work in my area (the East of England). Graham Cutmore of "Graham Cutmore Engineering" is one. The Alde engineer I spoke to described him as a "top man". Ray: I believe all the Alde approved engineers are independent and their costs vary. As you will know, Graham is based in Northamptonshire but covers the country. I am speculating of course, but If Graham travels further than the local engineer and adds a supplementary mileage fee then his bill will be bigger, no?

Thought I should share this in the hope that someone will kindly help me out... I have an Alde 2920 "Comfort" boiler, fitted in 1994. I bought the boat in 2004 and the circulation pump (manually activated with an "on-off" slider on the thermostat) has run flawlessly and silently since. I believe it is the same pump used in all the original comfort boilers and has changed little (but don't quote me!). Anyway this little fellah has been happily doing his job pushing a mix of water and glycol around my CH system from inside his plastic expansion bottle. Until recently when he threw all his toys out.... It didn't whine, like a bust bearing or bush, but clattered. The clatter only became audible after 20 minutes or so with the Alde on "full bore". If you already know the answer then I'd love to hear from you. Otherwise, you can "bail" now or toil to the end of the post! I removed the pump and took a long hard look at it. The shaft and spindle seemed straight and true but the notched lower washer was a little worn (compared to the similar sized cap washer) and stuck with crusty residue. I carefully cleaned it off. Spinning the impellor by hand didn't reveal any "slap" so I clamping the thing in a bucket of cold water and wired the motor to an obliging boat battery. It ran smooth and quiet for a couple of hours - no problem at all, even after I "tortured" it with hotter and hotter water. This persuaded me there might be nothing wrong with the pump, mechanically or electrically, except of course the middle of a big bucket is not its natural habitat - so not the same load. The next step was to banish any particles in the CH system that might have been getting stuck between the impellor blades and the surfaces of the impellor well (at the bottom of the expansion bottle). So with the help of a plumber, we introduced flush points and trickle-rinsed the entire system (using just domestic tap water) until it ran out perfectly clear. That done, we removed the expansion bottle from the Alde boiler so I could clean it out thoroughly, especially the well-end of it where the impellor sits, minutely scraping off vulcanised rubber (detritus from the lower washer) and other stuck "grot". We needed a variety of cunning tools for this job (owing to the awkward shape of the thing), including an old half round file and some emery paper wrapped around a "Henry" vacuum cleaner tube. But in the end we did manage to clean it up "as good as can be". After I refitted the pump inside it's bottle I continued my torture regime in the bucket. Everything looked and sounded good. We then relocated the expansion bottle (with the pump already inside) and recharged the CH system using 50% Glycol. I reignited the boiler, switched in the pump and waited. As before, the pump ran perfectly for 20 minutes then "clatter-clatter" just before the boiler shut down (with the thermostat set at around 25 degrees C). The noise is like sticking your fingers between the spinning blades of a 12 volt miniature fan. All I can think is that hot water causes the shaft, the spindle or the washers to move just enough so the impellor catches (to function efficiently there is not much space in the well for the impellor to spin). But the odd thing is that there is no warning. The pump goes from silent to constant clatter - not a gentle transition as the temperature rises. Instead there seems to be a precise critical temperature that triggers the problem. It then goes away when the water cools just enough. Finally, and for what it is worth, I did discover that unscrewing the cap a turn or two seemed to stop the clatter, albeit briefly. So we banged an extra "spacer" washer inside the cap to see what that would do (in case somehow the blades were scraping the bottom of the bottle) but it didn't make a jot of difference. Unless I can begin to understand the problem I am reluctant to buy a new pump (they are expensive little blighters). But short of doing exactly that, I really don't know what else to try. I'm stumped, basically... Any thoughts? Thanks, Dr8ton PS I phoned Alde for a chat but am yet to hear back from their engineers.