Hi, it measures 48.4 ohms.Analyser wrote:Before continuing, quickly check your dummy load is ok. Use a multimeter and it should measure close to 50 ohms when set to read resistance.
this: http://www.ebay.es/itm/262021256078
Hi, it measures 48.4 ohms.Analyser wrote:Before continuing, quickly check your dummy load is ok. Use a multimeter and it should measure close to 50 ohms when set to read resistance.
Hi, the data that RF-Head gave me are very different from the ones I have. According to him it should have between 30W and 40W and I have only achieved between 18W and 24W maximum. It also says that 5W of minimum when it drops me to about 0.3W. I'd rather not touch the coils, lest I spoil it.Analyser wrote:Ok, so you know that your dummy load is good.
I wouldn't worry too much about the power drop at the top of band, it's normal for no-tune amplifiers to have some variation with the frequency. I agree, a 10W drop on a 30W PA is a lot, but you may be able to gain some more power by opening the coils a little and see how this affects things.
The main point is that you've got it working again and that's a good starting point.
No, I'm using VHF1 but I've seen the other model and wanted to know if it can be used too or not.teckniqs wrote:Are you using the HUF1?
Thanks, I figured it would not work.teckniqs wrote:I've never tried but I doubt it as it's for UHF and many UHF transistors will not work for VHF frequencies.
I installed a RD30HUF1 that I have been given to test and it works just like the RD30HVF1.Sietedj wrote:Thanks, I figured it would not work.teckniqs wrote:I've never tried but I doubt it as it's for UHF and many UHF transistors will not work for VHF frequencies.
I have a DP-100 dipole.Albert H wrote:What kind of aerial are you using? A DC-shorted type like a Slim-Jim, J-Pole, or even a folded dipole helps to protect the output device against static.
Thanks Albert, I've been looking at this type of antennas but having to build it by myself is not easy for me. I do not have equipment to check that it is well done and it is something that I prefer to buy and to be sure that it is well. This dipole I have I know is not very good but to me it works quite well.Albert H wrote:You should consider a different type of aerial. You can easily build a J-pole, and they give a better match to your coax, a little bit of gain over a dipole, are truly omnidirectional, and provide a DC short. For a quick and easy aerial, there's nothing better!
Thanks Albert for your explanation. I think this type of antenna can not change frequency, it is done for a single frequency, and I need to be able to adjust to several frequencies, since where I live there are many pirates and you have to go changing from time to time. I was looking for a broadband but they are a bit expensive. I'll keep thinking what to do with the antenna, thanks again.Albert H wrote:A J-pole really is easy. All you'll need to get it right are an SWR Bridge, some wire wool and a tape measure! You'll also need either a heavy-duty soldering iron or a blowlamp.
The easiest way to make a J-pole is to use standard plumbing parts available in any hardware shop (even B&Q!). Buy two 3m lengths of copper plumbing pipe, a right-angle coupler and a "T" coupler. If the couplers are "Yorkshire" types, they come pre-loaded with solder - to join, all you have to do is clean the end of the pipe that you want to connect with the wire wool (you can't solder to dirty copper), poke it into the coupler and heat it up with the blowlamp until you see a bit of solder oozing out. Leave it to cool - it's easy to get your fingers burnt - and then carry on with the rest of the construction.
There are loads of instructions on the 'net for building a J-pole, and there are even really good on-line calculators which will give you all the dimensions that you need.
https://m0ukd.com/calculators/slim-jim- ... alculator/
http://www.hamuniverse.com/jpole.html
http://aa1zb.net/Antennas/J-Poles/J-Pol ... ewOld.html
Remember to coil up the last couple of feet or so of the feeder, so that you can make a roughly 5" diameter 6-turn coil of the coax about 6 inches from where it meets the copper. This simple choke isn't too critical, but will help to eliminate RF current running down the outer of the coax.
This is one of the very easiest aerials to get right. Your dipole won't match your feedline properly unless you have a Pawsey stub hiding there somewhere!
I'm going to study and try to make one see if I can, thanks Albert !!!Albert H wrote:The J-pole can be made adjustable. it will have a useful bandwidth of more than 1 MHz anyway if built correctly, so if you wanted to move from (say) 104.2 MHz to 104.7 MHz, the match would stay substantially the same.
If you're moving to different parts of the band,it's cheap and easy to build several J-poles - if you buy all the materials from a builder's merchant, you can make one for not much more than £5!