tag:blogger.com,1999:blog-6891312687175550342.post251977575902235957..comments2024-03-27T13:53:17.950-07:00Comments on GM4FVM's radio world: IC-7300, split IF, RF attenuator, transverter and ALC power spikeGM4FVMhttp://www.blogger.com/profile/10794029618635259984noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-6891312687175550342.post-25103981942574158222020-05-13T05:06:09.868-07:002020-05-13T05:06:09.868-07:00Jim,
Thanks
JohnJim,<br />Thanks<br />JohnJohnhttps://www.blogger.com/profile/12652458156345939665noreply@blogger.comtag:blogger.com,1999:blog-6891312687175550342.post-15514973177453080702020-05-13T02:57:11.195-07:002020-05-13T02:57:11.195-07:00John. As I understand it what you are doing with t...John. As I understand it what you are doing with this device is putting a loop in the RX line between the tx/rx relay and the receiver. The loop comes out to the outside panel of the rig. On one side is a socket with the rx from the antenna, and on the other side is a socket which connects directly to the receiver. Thus you have the rx from the antenna as you describe on one socket. You could, for instance, put a splitter in the loop and feed two receivers. This would be 3dB down on each receiver, but you can get amplified and isolated splitters, or you could build one of those. Maybe 3dB doesn't matter anyway if you use lower bands.<br />I am going to try to contact you direct about the product itself and if you do not hear form me please contact me QTHR (email address is on QRZ.com. 73 Jim GM4FVMhttps://www.blogger.com/profile/10794029618635259984noreply@blogger.comtag:blogger.com,1999:blog-6891312687175550342.post-10522361296746257742020-05-11T07:58:51.186-07:002020-05-11T07:58:51.186-07:00Jim,
Do you know of an easy way to use the TX ante...Jim,<br />Do you know of an easy way to use the TX antenna on an IC7300 as a separate RX antenna feed when the 7300 was in the RX state? I would have thought it would have been part of this mod or the DB6NT mod, but they only appear to show the IC7300 RX disconnection and re-route of the RX input to a separate socket.<br />Also the French Ebay link is now missing unfortunately, do you have any other contact details of the supplier?<br />Thanks, 73<br />John (G(3)PQA)Johnhttps://www.blogger.com/profile/12652458156345939665noreply@blogger.comtag:blogger.com,1999:blog-6891312687175550342.post-72603759954550841212019-06-14T07:53:18.512-07:002019-06-14T07:53:18.512-07:00Jan
I remember the HW-100 but I never owned one. T...Jan<br />I remember the HW-100 but I never owned one. The guy with the dummy load was using a KW-2000. I never liked them much, very heavy too. Even when I was first into radio in the late 1960s KW gear seemed very old fashioned.<br />Yes, I used an FT-101 with the valve-based plug removed from the back.<br />Your idea for the FT0817 is good.<br />The split rx/tx could be very useful in the future for several things. Although the 7300 has a waterfall, when I had the TS-590 I added a dedicated SDR to the transverter rx line and had a big screen display too. I used to use a Flex 1500 as transverter driver and it was very good too.<br />If I could have disabled the power from the 7300 PA I might have gone that way, but it did not seem practical.<br />I will be looking for you on the bands.<br />73 JimGM4FVMhttps://www.blogger.com/profile/10794029618635259984noreply@blogger.comtag:blogger.com,1999:blog-6891312687175550342.post-3768864472755655272019-06-14T07:22:09.133-07:002019-06-14T07:22:09.133-07:00Jim
When I built my first 2m transverter I was usi...Jim<br />When I built my first 2m transverter I was using a HW-100. There I removed the anode voltage from the PA and used the driver output. No problem with self oscillation, then ;)<br /><br />Now I do have an older FT-817 with a blown PA. That I might modify for use with a transverter, and then use a RTL-SDR as a spectrum scope.<br /><br />BTW on the IC-703 I had to file a bit off the adapter, then it all looked good enough for me to use. At the moment I am using the 703 as 10m TRX and having two other receivers (signal splitter) connected for monitoring, then I can still use the 703 for 10m (or transverter) and monitor the FT8 frequency and 28.200 for the international beacon net monitoring - at least when I do not transmit on 10m. If I need more power, I can add a 200-250W PA (that I have), or I can use my 100W HF transceiver. <br />Good luck to you, too. 73, JanJan, OZ9QVhttps://www.blogger.com/profile/03992431305032081854noreply@blogger.comtag:blogger.com,1999:blog-6891312687175550342.post-82227112420935609662019-06-13T06:04:05.401-07:002019-06-13T06:04:05.401-07:00Jan
Yes, they say that great minds think alike. I ...Jan<br />Yes, they say that great minds think alike. I think the heatsink is needed. However, the Kuhne board does not seem to have one, or perhaps I do not understand it.<br /><br />https://shop.kuhne-electronic.com/kuhne/en/shop/accessoires/other-components/Transverterinterface+for+IC7300+KIT/?card=1820#_tab_content3<br /><br />I had thought that it takes out the tx line before the PA. If the PA is still powered but not driven, I am not surprised that it can self-oscillate. So, I decided to go for the attenuator method.<br />I remember in the 1970s seeing someone using a valve tx directly into a dummy load at 100W and taking a very low level feed from the dummy load. He did this by having the dummy load in a cage (KW Electronics dummy loads were like that) and then taking a very low level drive via induced RF from a wire he ran inside the cage. Others used a tap on the dummy load.<br />Thanks for that and good luck. 73 JimGM4FVMhttps://www.blogger.com/profile/10794029618635259984noreply@blogger.comtag:blogger.com,1999:blog-6891312687175550342.post-50932017292662606322019-06-12T08:04:15.339-07:002019-06-12T08:04:15.339-07:00Jim,
I have successfully installed one of those RX...Jim,<br />I have successfully installed one of those RX adapters in my IC-703, and I plan do do the IC-7300 mod, too. Yes, I found the French one, too.<br />Regarding the attenuator, I may make use of some 50W 50 ohms loads (adding a heat sink) I have, and add a relatively high value resistor for high attenuation to a transverter input.<br />I see that we have similar ideas in that respect.<br /><br />73, Jan, OZ9QVJan, OZ9QVhttps://www.blogger.com/profile/03992431305032081854noreply@blogger.com