This modification to the Acom 1000 is to add an additional Fan to the Amplifier.I have been aware recently of how the temperature is very high whilst running qro in the Digital Mode (RTTY) Contests. Although the Amplifier copes exceedingly well in the conditions, I thought i would feel a lot happier if i could reduce the cooling time down more efficiently. I have a colleague that had done a similiar modification in the Acom 2000 and thus the reason for this modification.The proceedure was very easy and did not require any soldering at all. It was however easier to have another colleague to assist though as it can be a bit tricky manouvering the transformer whilst trying to carry out the work on the circuit board within the Amp.The first job is to remove the top cover from the Acom. It is easy to do but as always, make sure you have plenty of space to work, some clean cloths and/or towels etc then as the cover and other items are removed you will have no accidents such as screwdriver scratches or dents as the proceedure moves on. Once the cover has been removed, familiarise yourself with the Transformer and the area of the Amplifier in which you are going to work. The fan itself will be attached to the outside of the case and to do this we need to remove the transformer. The are we will be working on is shown in the photograph to the right. I am sure you will be aware which part of the Amplifier is the Transformer so no need to insert a photograph to show that, by my non-tech standards even i know that hi!The next thing we need to do is to negotiate our way into the Amplifier to move the transformer and therefore gain access to the area where we need to be. We need to remove four screws which hold the rear grill in place and to do this it is easier to remove the Transformer rather than fiddling about with fat fingers and struggling as a result. It should be noted here that i bought the second fan from the UK Acom agent, Ron Stone at Vine Antennas. This fan already came with four longer screws which are needed to bridge the larger distance created by adding this new unit. The four screws in place at the moment are not sufficient to complete this task.If you turn the Chassis onto its side you will see there are a significant number of screws in the bottom cover however we are only interested in the four large bolts that are shown in the bottom left of the photograph to the left of this text. After removing the two connecting cables from the transformer, carefully remove the two farthest bolts. So still secured with two of the four bolts, move the amplifier over the edge of the bench and remove the other two and this will leave the transformer free to be moved. It is important not to take out all four bolts at the same time as that will leave the transformer unsecured and free to slide whereever inside the case and which would ultimately cause damage to the componants or chassis.Once the transformer is out you will see that you have a large amount of room now so you can manoeuvre about with ease. Next step is to remove the grill from the rear ventilation space. Just undo the four small screws and remove it.
Now comes the trickiest part of the job and that is to run the two wires from the new fan, through the hole and to pass them through a very small hole in the circuit board directly above the access hole and directly adjacent to the chassis of the amp.
We found it easier to pass both wires through some old wire sleeving and then to pass the sleeving through the hole in the circuit board to its designated position. Of course a small straw or something similar could be used should you feel it necessary. Once both wires are through the hole in the circuit board, you will see adjacent to the hole that there is a small 24v connection point which is ready to accept the wires from the fan.
At this point we can now secure both the fan and grill back in place and remembering to use the four long screws that we mentioned earlier in the project.
Two cautionary notes here! The first is regarding the grill which you can deal with now or leave until later. We have to be careful to ensure that the fan blades in the new fan do not catch at all on the rear ventilation grill when it is replaced. You will see in the Photo here that the after completion the grill is bevelled inwards which without doubt would catch the blades (Photo above). I found it easier just to add a little pressure to the grill in order that it would bevel out and avoid any chance of it catching at all when re-built.
If it does catch after it is putback together, a small self-tapper slightly screwed in to the grill will allow you to pull it away without a problem of damage.
The other note is to remember, have you fitted the fan in the correct orientation? The fan will have an arrow marked somewhere on its edge which shows in which direction the air will flow when connected. You must ensure you have it correct or the Amp will overheat instead of cooling down!
The correct way....
The fan should pull air into the Amplifier (the arrow points in). You may feel some turbulence around the
fan entry which can mislead you into thinking it is extracting air, but it is not.
I will post the results of the modification on here in a few weeks but certainly at this stage i can say the cooling time and resulting temperature is far less than without the mod.
And finally………….If your workbench and Acom now look like these two photo’s – you went wrong somewhere hi !
( Thanks to Ron Stone at Vine Antennas for supply of the Fan and also John G4RCG for the
help and use of his superior equipment to complete the task!!)
73 de Charles…..
Vine Antennas pride themselves on selling ONLY High Class radio products from a wide range of suppliers.
In late 1994, Ron, GW3YDX, (an active DX and contest operator) set up Vine Antenna Products, mainly to source antennas which were not available on the UK market, and to counter the very limited choice available to the UK amateur at that time.
Since then, the product range has expanded to include valve amplifiers from Alpha Power (Formerly ETO) and ACOM Ltd, VHF transistor amplifiers from T E Systems in California, rotators from several manufacturers, and the excellent crystal and mechanical filters from INRAD.
They have very recently taken another step forward, and started selling transceivers from TenTec. They are now UK and Eire main agents for several of the main USA antenna manufacturers such as Tennadyne, Force 12, M-squared, GAP Antennas, and SteppIR. Vine Antennas are also now the main UK retail outlet for Optibeam and the excellent Versatower range as well as being able to supply Tennamast masts. They now also produce their own range of VHF yagis for 6 and 4m, too.
Vine Antennas have a simple rule when selecting products – “NO RUBBISH”, even if it would produce a whopping margin.
”You get what you pay for”
Ron Stone GW3YDX
As mentioned to us at his recent presentation at Silcoates School in Wakefield, Mike McGirr (K9AJ) is now Qrv on the dxpedition to Coroa Vermelha Island in South America as PW6C.
The IOTA group SA-062 is composed by two islands: Coroa Vermelha Island and Coroa da Barra Island. These close by islets are situated on the coast of Nova Viçosa, State of Bahia. Coroa Vermelha, the biggest island, is located about 10 nautical miles from the coast.
This island is formed mainly by sand banks which form small beaches in the middle of the atlantic ocean. These sand banks are rounded by coral reefs, and in low tides are formed natural pools with very good places for scuba diving. The second island is just a small coral reef that only appears above the ocean on certain periods of the year, and is called Coroa da Barra Island or Sebastião Gomes Reefs as known by some natives.
The IOTA SA-062 Group is the actual 6th most wanted IOTA group in South America, and 2nd most wanted in Brazil.
This DXpedition will be qrv until November 17, by a group of 6 operators who will deal with around the clock operations giving the world wide IOTA community the opportunity to confirm this rare IOTA group.
Good luck to the group and we wish them all well, tnx for the new one Mike (# 461)!
73 de Charles
It was good to hear this week that Belgium now have activators ready to go in the World Flora Fauna programme. The ONFF numbers cover around 18 different National Parks and Nature reserves in Belgium and congratulations to Gino ON3SSB for his appointment as ONFF’s Co-ordinator for the programme.
I don’t believe any of these numbers have yet been activated so along with the GFF team, ONFF have plenty of ‘new ones’ to give away. Please keep an ear to the radio and an eye on the cluster and when you hear the ONFF team please give them their support.
Winter is fast approaching and all WFF activators need your support and encouragement to get wrapped up on a freezing cold day to activate these areas on our behalf. If anyone reading this blog has any interest in activating new areas (whichever Country you are in) please contact either myself, Gino or any other WFF representative and we can give you all the information you require.
Have a good weekend and batten down the hatches until the storms pass at the end of next week!
73 de Charles
Hats off to the P29 Team too (again see previous entries), I don’t think i have ever heard as many PNG stations in such short a time!! On various bands and modes i worked P29VSR (Gordon G3USR) on OC-008, P29VCX OC-116, P29VLR on Green Islands OC-231 & also P21NI (Derek G3KHZ) on Woodlarks Islands OC-205, all three new IOTA references for me so thanks guys, good trip!
It was also nice to hear Steve 9M6DXX/p on the air again from Labuan Island OC-133. Sadly it wasn’t a new one for me but nevertheless a great signal and always a pleasure to hear him on air. (Qsl via MØURX).
TX3A, the Dxpedition to Chesterfield Islands (OC-176) has so far eluded me. This has been far more difficult for me and to be honest i have never even heard them yet. This one i think will have to wait for another day. If nowt else, it looks amazin (Image – Below)! Have a good week whatever the weather, good dx’in,
Many of the Special Events that i am involved in can be found in this category.
The main two events over the last few Years have been with ‘GBØANT‘ and also ‘GB4IPY’.
‘GB0ANT’ has been running now once per annum as part of the Worldwide Antarctic Program (WAP) and we are currently just passed 10,000 q’s in the log as we starts 2010 event. ‘GB4IPY’ ran for two years (now ended) to help in raising awareness of ‘International Polar Year’ and total qso count for this station was 9,555 q’s.
More information is available on the respective pages which can be found in the main Menu to the left of this page.
Other Special Callsigns include those of short event such as ‘GB1TAN’, the activation of the ‘TanHill Inn’, Britains Highest Pub in Swaledale, Yorkshire Dales National Park and ‘GB0WFF’ for the World Flora Fauna programme.
More information on all these items can be found somewhere on the site and photographs can be found in the bank of Gallery Photographs again found via the main menu.
If you have any comments either positive or negative, I would be happy to receive them via the ‘Contact M0OXO’ form or alternatively by an entry in the Guestbook.
Please also check out the Awards that are available for these events. There are numerous Awards for the WFF Programme and also for the Antarctic Activity Week. They can be found by navigating the menu sidebar and for any other enquiries please email me.
73 for now, regards, Charles…
Page undergoing a facelift!
||Lydden & Tempell Ewell Downs
||Nor Marsh & Motney Hill
Cushcraft MA5B, great antenna for restricted area.