|
Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members. |
|
Thread Tools |
25th Aug 2008, 9:01 pm | #1 |
Retired Dormant Member
Join Date: Dec 2005
Location: Wisbech, Cambridgeshire, UK.
Posts: 452
|
Receive converters
Hello all
Does anybody know where I could find some circuit diagrams for receive converters to convert 20 mtr and 40 mtr to my 80 mtr receiver. I would also like to convert 2 mtr, 4 mtr and 6 mtr if possible to any of the above, direct or otherwise. Many thanks Mike |
25th Aug 2008, 10:59 pm | #2 |
Rest in Peace
Join Date: Apr 2008
Location: Worcester, Worcestershire, UK.
Posts: 330
|
Re: Receive converters
Hi Mike. Do you want valves or transistors?
There are suitable circuits for converters both valve and transistors covering 2,4,and 6 metres in older ARRL handbooks and also in the RSGB handbook as well as in old RSGB and Short Wave magazines. If you are really stuck I could at least find the relevant copies. However don`t forget that the VHF bands are quite wide and therefore the tendency was to convert to 28 Mc/s. Pat |
26th Aug 2008, 7:56 pm | #3 |
Retired Dormant Member
Join Date: Dec 2005
Location: Wisbech, Cambridgeshire, UK.
Posts: 452
|
Re: Receive converters
Hello Pat
Thanks for reply, sorry should have said my receiver is all built from modern components including many ICs. Although I have a few ideas to try anything you can find would be a great help. Regards Mike |
12th Sep 2008, 10:43 pm | #4 |
Pentode
Join Date: Jun 2006
Location: Malaga, Spain.
Posts: 235
|
Re: Receive converters
Hi
see if you can get hold of some old copies of the ARRL or RSGB manuals, they had pages of converters and depending on the year were valve, transistor or both. mike |
13th Sep 2008, 8:43 am | #5 |
Retired Dormant Member
Join Date: Mar 2003
Location: Bishop's Waltham, Hants, UK.
Posts: 939
|
Re: Receive converters
there have been a lot of designs over the years, with several appearing in Practical Wireless.
It is more usuual to convert the VHF and UHF bands to 10m, as the 10m band is 2MHz wide, which gives easy tuning over 6m, 4m and 2m, and a small section of 70cm, however, most converters have a simple IF output stage, which is either untuned, or only consists of a low Q circuit at the IF frequency, so if you select a suitable crystal, it would be easy to modify for the IF frequency you want (3.5MHz), but you will only get a section of the new band that is the same as your receiver can tune. Jim. |
14th Sep 2008, 10:49 am | #6 |
Hexode
Join Date: Feb 2006
Location: Diss, Norfolk, UK.
Posts: 386
|
Re: Receive converters
Hi.
There is a circuit in the 1990 ARRL handbook for a double conversion receiver. The first mixer produces a 80m output which in turn is fed into the second mixer, this input is also used as a direct single conversion input at 80m. You could use the first mixer/converter circuitry to feed your existing 80m receiver. This combined with one of the many 2,4 & 6m to 10m converters should cover your requirements. Trevor |