[Repeater-Builder] Re: VHF Engineering Tx Help Needed
Hello Doug, I had a similar problem with a VHF Engineering Transmitter-PA. Incoming signals would key the repeater but there was no RF output. First you need to find out if the fault is in the TX or the PA. The output of the TX alone should be 1-1.5W. If that's ok, then you should focus on finding a problem in the PA. If I remember correctly the way I tested it was by connecting a power meter to the output of the TX to see if the output power was ok. I got 1-1.5W as expected so the next step was connect a 1W input signal taken from a handheld radio to the input of the PA. The output was almost zero. In my case the fault was with the final transistor (2N 6081). After replacing it the output was around 3-4W but after following the tuning procedure described in the manual it went up to 15W. You might want to do this first, just in case the low output is due to a misalignment problem. Now if the problem is with the TX module... I would check if the transistors are ok... You can get all the manuals from the Repeater builder website as pointed out by Eric. Hope this helps. 73, Andreas - 5B8AP --- In Repeater-Builder@yahoogroups.com, Eric Lemmon [EMAIL PROTECTED] wrote: Doug, The Repeater-Builder site has good info on VHF Engineering equipment. Here is the PA manual: www.repeater-builder.com/vhfe/vhfe-pa-144-220-450.pdf 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of dadavies3 Sent: Wednesday, November 07, 2007 2:24 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] VHF Engineering Tx Help Needed I have an old VHF Engineering 144 MHz. repeater transmitter that has very low output. I would like to find someone that has experience with one of these that can help me trouble shoot it. Any help is appreciated. Doug VE7DRF
[Repeater-Builder] Re: VHF Engineering Tx Help Needed
Hello Doug, I had a similar problem with a VHF Engineering Transmitter-PA. Incoming signals would key the repeater but there was no RF output. First you need to find out if the fault is in the TX or the PA. The output of the TX alone should be 1-1.5W. If that's ok, then you should focus on finding a problem in the PA. If I remember correctly the way I tested it was by connecting a power meter to the output of the TX to see if the output power was ok. I got 1-1.5W as expected so the next step was connect a 1W input signal taken from a handheld radio to the input of the PA. The output was almost zero. In my case the fault was with the final transistor (2N 6081). After replacing it the output was around 3-4W but after following the tuning procedure described in the manual it went up to 15W. You might want to do this first, just in case the low output is due to a misalignment problem. Now if the problem is with the TX module... I would check if the transistors are ok... You can get all the manuals from the Repeater builder website as pointed out by Eric. Hope this helps. 73, Andreas - 5B8AP Doug, The Repeater-Builder site has good info on VHF Engineering equipment. Here is the PA manual: www.repeater-builder.com/vhfe/vhfe-pa-144-220-450.pdf 73, Eric Lemmon WB6FLY -Original Message- From: mailto:Repeater-Builder%40yahoogroups.comRepeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of dadavies3 Sent: Wednesday, November 07, 2007 2:24 PM To: mailto:Repeater-Builder%40yahoogroups.comRepeater-Builder@yahoogroups.com Subject: [Repeater-Builder] VHF Engineering Tx Help Needed I have an old VHF Engineering 144 MHz. repeater transmitter that has very low output. I would like to find someone that has experience with one of these that can help me trouble shoot it. Any help is appreciated. Doug VE7DRF No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.15.27/1121 - Release Date: 9/11/2007 7:29 ìì
[Repeater-Builder] Re: VHF Engineering Tx Help Needed
I'm surprised there is not more interest in VHF Engineering Gear here on the Group... but their repeater receivers (modules) were/are kind of crappy so you don't often find them still in service. I've got a snot full of VHF Engineering TX strips around and a number of them still in service. Doug, I can help you off the Group if you need something. Their Transmitter boards were pretty straight forward so helping you with those issues is fairly straight-forward. cheers, skipp Eric Lemmon [EMAIL PROTECTED] wrote: Doug, The Repeater-Builder site has good info on VHF Engineering equipment. Here is the PA manual: www.repeater-builder.com/vhfe/vhfe-pa-144-220-450.pdf 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of dadavies3 Sent: Wednesday, November 07, 2007 2:24 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] VHF Engineering Tx Help Needed I have an old VHF Engineering 144 MHz. repeater transmitter that has very low output. I would like to find someone that has experience with one of these that can help me trouble shoot it. Any help is appreciated. Doug VE7DRF
